To get the carbon off, you gotta blast those valves with the walnuts bro...any nuts that fall down into the combustion chamber and get roasted, you simply collect in a "catch can" and serve those caramelized nuts at your next party.
Old Mercedes engines had direct injection. The intake ports would clog with a substance nearly as hard as diamonds. 4 hours to bead blast one head clean. It would slowly loose power over the years till it would barley run. No walnut shells were going to get rid of that crud.
@@EngineeringExplained What is your opinion of catch cans? And if you think they're beneficial, do you think they aren't standard equipment because they need to be emptied periodically (or for some other reason)?
You got me curious, because I don't recognize it either. Mo is molybdenum. I don't blame you for not having that one memorized. It sounds more like a pop star's clothing line than an element.
It's used in high grade alloys and lubricants. Most people just call it moly. It's mined quite a bit in the north west, but South American mines and price crashes have slowed that down. It's a weird shiny purple
I had an BMW E90 335i with the DI N54B30 engine; had about 70K miles on it. One night I got bored and decided to pull the intake manifold off to see what my intake valves looked like after I had learned about the carbon deposit issue. OH. MY. GOD. The sheer amount of black carbon just caked and caked on every single one of them blew my mind. Luckily the problem was so well known on this car that there are valve blasting kits on the market that made the DIY job relatively easy. Still though, what a massive engineering oversight.
@@_aullik No for real, only people from some nations think it's hard to memorise. Some languages have things like PDK: Porschesdoppelkupplungsgetriebe.
thanks! i can usually follow your explanations of these and other somewhat complex, complicated systems--outstanding work!!! as a result i feel (as an older person buying used vehicles vs new) i have a better chance of selecting something that may be a little more reliable and less demanding on the pocketbook. i never cease to be amazed at how you get to the meat of the issue without putting me to sleep!
thanks! looks that way--i got all of my car trading hopefully out the way last century--now it's all about reliability and decent gas mileage--but still, if i come across a car with fins on it, i might be tempted...
I have a PI + DI motor and love it, good horsepower with great economy and no carbon build up, you can't ask for more really. Toyota Mark-x 350S. 2GR-FSE motor, 314hp.
My 2020 2.5 Toyota Dynamic Force Engine has both port and direct fuel injection. I am totally amazed at my 2.5 Dynamic Force engine in my 2020 Camry LE (8,350 total miles) I recently took a 445 mile trip that put my car through just about all the scenarios a car could face including, freeway, hills, mountains, long gradual inclines, long gradual declines, 78 miles of winding uphill, downhill, sharp turns, not so sharp turns, manually downshifting, manually upshifting, and driving around a small coastal California town of Fort Bragg for two days. After I came back home I filled up the tank to check for the first time my gas milage turned out to be...an amazing "35.8 miles per gallon." I had to redo the numbers on my calculator to double check...445 miles divided by 12.4 gallons of gas. I am totally amazed! And all these miles were not "easy interstate miles"...only about 125, or so. My car performed better than I anticipated and this engine...totally amazed me! The car is rated for 39 MPG (freeway) on the window sticker. It looks like it would do even better! Totally amazing!
Dual fuel injection, the best of both worlds. I had a feeling this system will become more common in the long run. The newer Ford Mustang GTs also has dual fuel injection, which is awesome, and once this system gets more improvements, I bet most of the automakers will convert to dual fuel injection. I wouldn't be surprised if I see more Toyotas, Fords, Chevys, Volkswagens, even Mazdas adopt this setup in the future
DI engines will build up much more carbon than PI engines, and Fuel Additives cant remove carbon on intake valves. And DI engines are very sensitive to temperature. In high temperature environments, more fuel needs to be injected to reduce the temperature of the cylinder. However, the cooling effect of the injecting fuel is not good, engine limits the power output in case of overheating.
The only way to clear the carbon deposits on the intake valve is to disassemble the intake system. DI engine need clear carbon deposits every 40k~60k miles.
Hey Jason! Thank you for the great content that you post all the time. I would be very interest in getting your take on the auto Start/Stop engine function found in most modern cars today. Is it good, or is it actually bad? Your input would be highly appreciated!
DI engines with walnut blasting may make the valve look good. However, if that blast does not touch valve seat, carbon build up will cause burnt valve.
Actually Toyota’s reliability comes from their engineers and their Kaizen philosophy in their whole design and auto assembly process. Everyone had port injection by the 90’s, and not every auto maker made reliable vehicles like Toyota.
Stratified charge: what's old is new again. I remember when the Honda CVCC engines made their appearance here in the States in the early 1970s along with Honda's television commercials touting its benefits. As for blow-by, with the electronification of today's cars, catch cans with a solenoid valve to the sump can solve the valve deposit issue for the most part, EGR excepted. This seems inevitable to me as engine makers reach higher for fruit. No more low-hanging stuff to tweak.
If you look underneath the valve cover of many direct injected engines today, they already have an extensive oil separation system for the PCV, plus a direct pathway to the engine sump for oil drainoff (no valves required if the tube goes straight down below the oil level). One example of this is the Ford 2.7T, and another is the Honda Civic Type-R engine. Catch cans aren't really a great solution, because for the most part they either aren't catching enough oil particles (today, proper PCV oil separation systems are capturing sub 1 micron particles), or they are too restrictive. And in the winter, they freeze (which is really bad for your car as crankcase gases go out the fresh air tube... and when that freezes... blows your seals). All of those catchcan ads you see on forums are only telling part of the story when they say "LOOK HOW MUCH WE CAUGHT!!!11!" when they show off the fluid, because the fluid is a mix of water, gas, and oil. Gas and water you don't typically care about because they burn off when you drive, but the oil is what causes the deposits (the proper way is for those catchcan companies to actually heat the fluid so that only oil is left).
VW 2.0TSI engine owner knows the carbon build up problem. At +/-50 000miles theres a 2mm. crust behind the valves causing cold start missfire. Hope VW will change to PI and DI combo soon :)
You can just buy a oil catchcan and reduce the problem. And if VW's TFSIs actually met Toyota's specification about valve clearance from the 1980, then you would have less oil on your valves too. By the way, if you don't drive your car for a while (like weeks to a month) then the carbon deposit can dry out and flake of, these flakes CAN get in your engine when starting it again. p.s. I said "can", not "will". But engine builders say that if you leave an engine disassembled for a week or 2, the carbon fall off as soon as you pick up the valves standing on your desk.
ICE is so clean and efficient these days! Considering what they were like with carburetors these modern engines are almost miraculous. I wish the EPA would back off and stop raising the bar.
D4-S training talks for my job specifically mentioned carbon buildup. D4-S has an injector cleaner cycle that shoots a high-pressure air-fuel mixture laterally across the notch in the injector tips to clean them. It happens during idle every approximately 17k miles.
Got a real laugh out of the Moe for Molybdenum, I have a feeling you're pulling our collective leg there. As a mechanic my eye went immediately to the right side of your white board. I was bouncing out of my chair until you mentioned valve deposits, the bugaboo of DI! Ask anyone who has had to have their BMW's DI intake valves blast cleaned how big (expensive) a problem DI resultant intake valve deposits can be.Always enjoy your videos. If you weren't kidding about "Moe", well chem wasn't my strong suit either.
This video makes me wonder if Atkinson cycle DI engines might avoid carbon buildup issues because they force gasoline into their intake runners, where the gas can clean the valves. Perhaps this could be a video in the future?
Mine sounds normal as during idle (when you will hear them outside the car) only one set is used at a time. You can hear the change when it suddenly switches from one to the other as it warms up, but overall it's no noisier than any other fuel injected engine.
At about 5:15 you mention that you start injecting fuel (port injection) during the exhaust stoke when the exhaust valve is open and the intake valve is closed. Would this not just have the effect of spraying fuel on the back of a closed valve?
lexus already knew about carbon build up of DI only design, that why when they released their flagship sedan 13 years ago, both DI and PI is used on their LS460. As the LS460 needs to be their most reliable model.
Suppose that’s why Ford added port to the ecos. But to be fair carbon build up isn’t a big issue for most people… some people will melt down with that comment but it’s true. Just drive. Change your oil 5-8k.
Use top tier gas. Ford people are installing catch cans to collect crank case blow by. Lets not forget drilling a hole in your turbo Intercooler intake to drain fluid from you turbo intake air. Lets not forget 1.5 liter Eco boost 2016 to 2018 that loves to put coolant from the head gasket to the cylinder. Can watch videos of Ford Eco boost pickup motors rebuilds all day long. and then watch Ford Eco boost rebuilds because the first rebuild was done wrong. Or watch "Ford Boss Me" videos that says change your synthetic oil every 3,000 miles or else. Beats me why people are lining up to buy Mavericks and Broncos with Ford's track record.
The legal department likely advises engineers to not mention the fact that the engines they are developing have inherent flaws in them and as a result could open them up to legal problems and possible settlements.
@@EngineeringExplained Is there any other brand than Toyota and they D4-S who are using double injections direct and port ? Never heard anybody else doing that, since Toyota introduced Its D4-S.
@@MrNangu Ok good to know! But compare to Toyota It's only 1 engine in VW. While Toyota already many engines. So I would go for a Toyota rather than a VW which isn't reliable at all!
A lot of engine oils have Molybdenumdisulfite as an anti-friction additive..... Now guess what that "Mo" stands for and how it gets onto your valves....
I have two questions: -for a PI+DI do you need two differentes fuel system of differents pressures ? -does that work with diesel engine cause diesel only uses DI right ?
single source, the DI injectors are driven by a secondary high pressure pump that is mechanically driven off the cam. In DI only it's the same way actually, 2 pumps.
As they said one system, two pumps. But if you have a diesel engine you can get many of the same benefits with even more efficiency by using a propane injection system that puts propane in the intake system and causes a more homogeneous charge of fuel to be burned by the diesel fuel when it is injected. Then the diesel fuel becomes like the sparkplugs controlling the timing of the combustion.
@@davidscott5903 You're right, except methane is actually better for diesels. A diesel engine can work on 45% propane/butane and 55% diesel, OR it can work on 10% diesel and 90% methane. A diesel engine that runs partially on methane will have increased power output and decreased emissions because of the homogenous a/f mix. The only drawback is that you need another tank to be placed in your car/truck and you need the system to be setup and tuned in. That's not to big of a deal when you factor in propane, butane and methane are all a lot cheaper than diesel.
@@sasjadevries The only reason that I mention using propane is because of the availability of propane in the USA, and the fact that it is in liquid form in its tank. I didn't know about the amount of difference in ratios. Do you know the reason for the difference? I would like to know if you can find out. Thank you.
He forgot to mention Mazda engines run the intake valves at 700 degrees to burn off carbon deposits on intake valves. And he didn't mention oil catch cans can capture the blow by. Maybe someone can make an EGR filter now too. I love how electric cars don't have any of these problems though. I'm just waiting til an electric car has a 600 mile range!
@@tails300 good question. I'd like to know as well. I know Ford and Toyota have engines with both port and direct injection. Not sure if any other manufacturers are doing that.
Great explanation. I wish I knew how my Coyote chooses to utilize both its port and direct fuel injectors, and at what RPM ranges. Thanks for your excellence once again on the whiteboard!
Hello, First of all thanks for sharing video. I do have few query, appreciate your reply 1. Does this video is apt for gasoline only or for CNG also. 2. In PI, during injection of fuel it will displace incoming air thus affecting volumetric efficiency, considering Atkinson cycle.and thus less power will be produced.
manish mishra Yes, in CNG there is a displacement of air in PFI, but the required pressure for DI is quite high which usually needs a high pressure fuel pump. Usually this is done only with LNG. Westport Power does a dual fuel (diesel plus DI LNG) which has one of the lowest CO2 for a combustion engine. Generally for SI engines, though, turbocharging is cheaper than DI for CNG and that is what most engine manufacturers do for CNG, though some don’t turbocharge but instead raise the compression ratio to roughly 12:1 and the efficiency improvement can offset the air charge loss from fuel displacement. The air displacement for petrol PFI is lower than the air density improvement from cooling, but this is not the case with CNG which has roughly 10% air volume reduction.
Obviously depending on the application, it seems as though you get the best of both worlds with Port + Direct Injection, thank you for the explanation on all of the variants. It trips me out that all of these ways to inject fuel were all from the minds of engineers. It's pretty rad if you ask me.
Thanks for tackling this, Jason. I have been curious about some of the specific techniques used in the D4-S system on my FA20 and found there is little info out there. Wherever you got this info thanks.
Hello! Big fan of your videos. One thing got me curious, for more power isn't it better to use port injection at high rpm? My thought is that direct injection is limited by it's opening time. As far as I know Vw 1.6 fsi engine is ok at low rpm and it's quite torky, but at high rpm is not brilliant... a port injection engine may be not so efficient but for power it's more useful (ex: Lamborghini Aventador v12 6.0 mpi)
jack GB the valve lifters can get noisy sometimes making a ticking or tapping noise when in park or idling at a red light but its really only once in a great while it does it. The gx460 though with the 1ur-fe is notorious for it (like the guy above me says)
And don't forget throttle body injection! That one was probably the most revolutionary of all... And there were electronically controlled carburetors, with oxygen sensors. And my favorite, mechanical fuel injection. ;)
Engineering Explained, and Savagegeese reviews, are the only ones I have seen address the problems with Direct Injection and carbon build up. Some vehicles have severe build up as early as 20,000 miles, they then have to spend about $1,000 to fix it, until the next time. Hopefully Dual Injection will become standard in the future. Until then, some Toyota's and Ford's F-150's have Dual Injection, or a few still have Multi-Port, like Chrysler/Ram.
In the future? It already is a standard. Only some very low end models are still MPI only. The worst carbon deposit problems I've seen so far on the internet seem to be on turbo engines
That's because carbon build-up can vary from engine to engine- and yes, that means not every DI engine has valve deposits. Most newer engines are utilizing a sub 1 micron PCV oil separation system, which in most cases is sufficient to keep intake valve deposits away on DI engines. There are a couple of systems out there, you can youtube search "Dana Multitwister" for one type.
As a mechanic, I've noticed my wife's Mazda2 Skyactiv engine doing its retarded timing catalyst warm-up cycle too. The car sounds cool, it's got a gruff, slightly raised idle speed like a poor man's world rally car! It is linked to the wheel speed sensors, so if we roll it back down the driveway during warm-up it cuts out & returns to a normal quiet idle before you drive off.
Dangermouse Usually these days they will use a software model of the catalyst temperature to switch the catalyst light off mode, at least that’s what my software does. On cars with this algorithm if you drive off that mode kicks out earlier than if you just let it idle.
Good job on this vid. I never nod off watching your stuff. My solution for my new 3.6 V6 was a catch can and you should see all the crap it catches, none of which should be ingested by any engine port injected or not🤮
Thanks for the video :) really explained a lot. Wonder if the whole DI issue is the same for diesel engines? I've never experienced modern Diesel's torque (been meaning to for years 🙁) but we have an old Peugeot 405 indirect injection turbo diesel which has decent torque compared to most modern cars here; the 1.5 liter petrol engines in Toyota Allions, Premios, and 1 litre Indian cars; and has lasted 25 years without any major engine repair... I wonder if modern diesels would last like them
So from what I understand is port injection is the way to go. Deposits are reduced by a landslide but still possible from the image shown in the video. My question is will an engine still benefit from an oil catch can or oil separator even if it’s port injected or is it overkill and not necessary? Thanks in advance!
Manually cleaned the intake ports/valves my 2010 gti twice... I wish VAG brought the euro motors over to the US because those came with 2 sets of injectors (like in the new rs3)... Whether or not the car has a dual injection system will influence my next vehicle purchase.
Hey. Is it possible,or do they do this already. Ok. So idk much about cars or how they work. So please don't make fun. I watched your video but could only follow so much. Now I know they spray gas into the engine. My question is can they or do they harness the gas fumes and send it separately to the cylinders and if so how. And if not why not? Wouldn't it be basically free fuel? Possibly being able to just start the car,or idle the car, or give it a power boost? Again,I'm not a car guy and never given them any real thoughts. But I'm guessing the fumes are probably not being utilized efficiently and if you could create a system to gather them and distribute them appropriately, wouldn't it improve the average car? I might seem like I'm not very smart ,but I love inventing and fixing problems. I didn't go to college and have zero experience in this area. I just think about a lot of things and hope to become an inventor one day. I don't have anyone to talk to about this. But yea, any feedback would be cool.
This video was very well done for someone like myself fascinated and curious about the internal functionings of the combustion engine but not a full on gear head by any stretch of the imagination. I gotta subscribe so that I can learn more! 😉
@Engineering Explained I wonder how the "D-4S Injection" in all Toyota's newest engines, such as the one found on the M20A-FKS (corolla hatch), work to reduce the carbon build up on the intake valves... they state it has a "low-pressure" port injector unlike the higher power port-only injected engines of yesteryear. I know that the 2UR-GSE (Lexus 5.0L V8) had both port and direct injection as well upon its inception, but they never specifically called out the port injector to be "low-pressure". I know many ISF owners whom have viewed their intake side and upon inspection for carbon build up noted there to be very minimal amounts if not nearly any present; as crazy as that sounds. I'd be curious to see if Humble Mechanic would also have an opinion on this. All this to say I'm not sure if Toyota even got it right, as at least on my e210 hatch with the above engine I'm experiencing cold start misfires indicative of carbon DI issues.
Thank you for this informative video about DI and PI engines. Could you also do a video on how to reduce or clean carbon deposits on DI engines? Much appreciated!
Hi, great clip, but i have few questions. Maby it depend on car brand, but do PI and DI its own map in ECU? Also, if you check wolkswagen engine EA888 3gen. and 3gen+, they used dual injection on engine CJEB, but on newer version 3gen.+ its not used anymore. Do you have ideas what are cons to use it?
This video makes me think of Ford 2.3 EB ranger/mustang/explorer engine is only DI. The 1st gen 3.5 EB was DI only now the gen 2 3.5 EB is PFI/DI along with 2.7 EB. They will never tell you about the carbon but slowly all their motors are changing over even the 3.3 non turbo v6 has both injection methods.
Thank you for this video. I am a long time subscriber. I just bought a 2018 Hyundai Sonata Limited with a 2.4 GDI engine as a family sedan. This car currently has 16,000 miles on it. I really want to take car of it, as I payed cash and have never owned a car this nice in my life. Do you have any recommendations/videos on Mitigating carbon deposit issues on the intake valves? I plan on replacing the PCV valve every 20k miles. I really appreciate the effort and diligence you put into your videos. any help would be greatly appreciated.
Is this normal to carbon buildup which is dry in exhaust tip in (petrol) gasoline Toyota yaris sedan 2019???? car driven only 4000 miles In my finger little amount of dry black carbon came out when I touches the exhaust tip .... Please reply
Very awesome video! This made me super happy to hear when Toyota was pushing the D4S dual injection system because it is so efficient. You get the best of both worlds without being stuck with the compromises of DI.
Hello Can a mpfi engine be converted to direct injection?? If yes which company does and the kit?? And Can a GDI engine be fitted with CNG kit?? If yes which company?? Kindly send links if possible.
Are there any manufactures that only use port fuel injection system? I'd rather stay away from any direct injected systems because of the cost ,(labor, parts, time down, money), to remove the carbon buildup on the intake valves.
Direct injection reduces knock. Isnt this the same term some use for detonation which is bad? And happens alot more on direct injected due to higher compression and carbon buildup? Surprised the DI crosstrek you have hasn't had this issue yet. My motor spent its whole 25k miles of life in the lower rpms driven slowly. by 15k it had such bad carbon buildup causing LSPI that Subaru condemned the motor and told me drive it till it goes. Sounded like bolts in a glass jar being shaken.
I always appreciate the time and effort you put into making these videos. Thanx man... All the way from 🇿🇦
Thanks! Got engaged to my wife in your beautiful country a couple years ago! :)
@Jeffrey Cheng what
Jeffrey Cheng weird place to vent these types of thoughts...
To get the carbon off, you gotta blast those valves with the walnuts bro...any nuts that fall down into the combustion chamber and get roasted, you simply collect in a "catch can" and serve those caramelized nuts at your next party.
A proper roast.
lol
Get that guy from Ice Age to handle it for you and you're good to go.
Old Mercedes engines had direct injection. The intake ports would clog with a substance nearly as hard as diamonds. 4 hours to bead blast one head clean. It would slowly loose power over the years till it would barley run. No walnut shells were going to get rid of that crud.
@@EngineeringExplained
What is your opinion of catch cans? And if you think they're beneficial, do you think they aren't standard equipment because they need to be emptied periodically (or for some other reason)?
You got me curious, because I don't recognize it either. Mo is molybdenum.
I don't blame you for not having that one memorized. It sounds more like a pop star's clothing line than an element.
CrMo-steel? Ring a bell? :p
I had it memorized for god knows what reason
@@flyfaen1 piston rings
It's used in high grade alloys and lubricants. Most people just call it moly. It's mined quite a bit in the north west, but South American mines and price crashes have slowed that down. It's a weird shiny purple
@@danielrouw2593 I pronounce it moly-bend-um. Easier to say.
Jason, kind of dude that polishes his white board after every use
Cleaner than my cars for sure!
Doesn't everybody???
I had an BMW E90 335i with the DI N54B30 engine; had about 70K miles on it. One night I got bored and decided to pull the intake manifold off to see what my intake valves looked like after I had learned about the carbon deposit issue. OH. MY. GOD. The sheer amount of black carbon just caked and caked on every single one of them blew my mind. Luckily the problem was so well known on this car that there are valve blasting kits on the market that made the DIY job relatively easy. Still though, what a massive engineering oversight.
Does hours of research about fuel injection. Not interested enough to type "Mo element" into google. I see your priorities :).
.. Molybdenum btw
To be fair. He might have forgotten the name during the recording of the video. It really is an annoying name.
@@_aullik No for real, only people from some nations think it's hard to memorise.
Some languages have things like PDK: Porschesdoppelkupplungsgetriebe.
Kogo: was that the important part of this video? I thought it was about the injection system? Stop complaining just to get noticed...
Molybdenum is an important element in high tech steel metallurgy.
thanks! i can usually follow your explanations of these and other somewhat complex, complicated systems--outstanding work!!! as a result i feel (as an older person buying used vehicles vs new) i have a better chance of selecting something that may be a little more reliable and less demanding on the pocketbook. i never cease to be amazed at how you get to the meat of the issue without putting me to sleep!
Really appreciate it, thanks for watching Greg!
Greg, the answer to the question is easy . dont buy a direct inject engine car.
thanks! looks that way--i got all of my car trading hopefully out the way last century--now it's all about reliability and decent gas mileage--but still, if i come across a car with fins on it, i might be tempted...
@@jhndijkman Most engines are direct on the market today.
@@justd02ofus yes, that is a real problem.
I have a PI + DI motor and love it, good horsepower with great economy and no carbon build up, you can't ask for more really.
Toyota Mark-x 350S.
2GR-FSE motor, 314hp.
Toyota makes awesome v6 engine
BACK IN MY DAY WE JUST USED GAS HOSE THAT SQUIRT GAS ON THE VALVE COVER
Modern cars and the dang electo-units.
AND YOU LIKED IT~!
My 2020 2.5 Toyota Dynamic Force Engine has both port and direct fuel injection. I am totally amazed at my 2.5 Dynamic Force engine in my 2020 Camry LE (8,350 total miles) I recently took a 445 mile trip that put my car through just about all the scenarios a car could face including, freeway, hills, mountains, long gradual inclines, long gradual declines, 78 miles of winding uphill, downhill, sharp turns, not so sharp turns, manually downshifting, manually upshifting, and driving around a small coastal California town of Fort Bragg for two days. After I came back home I filled up the tank to check for the first time my gas milage turned out to be...an amazing "35.8 miles per gallon." I had to redo the numbers on my calculator to double check...445 miles divided by 12.4 gallons of gas. I am totally amazed! And all these miles were not "easy interstate miles"...only about 125, or so. My car performed better than I anticipated and this engine...totally amazed me! The car is rated for 39 MPG (freeway) on the window sticker. It looks like it would do even better! Totally amazing!
I had a coworker that has the 2018 Camry with the dynamic force 4-cylinder and they got 44 mpg-hwy
@@matthewmiller2268I have a 2018 Camry and I can get close to 50 on the highway. Amazing!
Dual fuel injection, the best of both worlds. I had a feeling this system will become more common in the long run. The newer Ford Mustang GTs also has dual fuel injection, which is awesome, and once this system gets more improvements, I bet most of the automakers will convert to dual fuel injection. I wouldn't be surprised if I see more Toyotas, Fords, Chevys, Volkswagens, even Mazdas adopt this setup in the future
Very complicated and expensive. Is it worth the complexity??
@@brysortho Yes, and a lot!
Dont buy gdi engine.
Buy normal engine = 0 problems
Carbon build up with DI engines is a disadvantage...
DI engines will build up much more carbon than PI engines, and Fuel Additives cant remove carbon on intake valves. And DI engines are very sensitive to temperature. In high temperature environments, more fuel needs to be injected to reduce the temperature of the cylinder. However, the cooling effect of the injecting fuel is not good, engine limits the power output in case of overheating.
The only way to clear the carbon deposits on the intake valve is to disassemble the intake system. DI engine need clear carbon deposits every 40k~60k miles.
@@plumwolf280
Now I have realised this is probably what killed my Mazda 6 gen 1 at 120,000 miles. 😭
Direct Injection Sucks, OK! Got it....
Hey Jason! Thank you for the great content that you post all the time. I would be very interest in getting your take on the auto Start/Stop engine function found in most modern cars today. Is it good, or is it actually bad? Your input would be highly appreciated!
Its a nightmare , Already seeing chewed up flywheels,Benix and starter gears.. They all have to work 20 times harder than a standard start truck.
DI engines with walnut blasting may make the valve look good. However, if that blast does not touch valve seat, carbon build up will cause burnt valve.
That is why 80's and 90's Toyota engines were reliable - port injection
symmetry08 honda says hi
Actually Toyota’s reliability comes from their engineers and their Kaizen philosophy in their whole design and auto assembly process. Everyone had port injection by the 90’s, and not every auto maker made reliable vehicles like Toyota.
Stratified charge: what's old is new again. I remember when the Honda CVCC engines made their appearance here in the States in the early 1970s along with Honda's television commercials touting its benefits.
As for blow-by, with the electronification of today's cars, catch cans with a solenoid valve to the sump can solve the valve deposit issue for the most part, EGR excepted. This seems inevitable to me as engine makers reach higher for fruit. No more low-hanging stuff to tweak.
If you look underneath the valve cover of many direct injected engines today, they already have an extensive oil separation system for the PCV, plus a direct pathway to the engine sump for oil drainoff (no valves required if the tube goes straight down below the oil level). One example of this is the Ford 2.7T, and another is the Honda Civic Type-R engine. Catch cans aren't really a great solution, because for the most part they either aren't catching enough oil particles (today, proper PCV oil separation systems are capturing sub 1 micron particles), or they are too restrictive. And in the winter, they freeze (which is really bad for your car as crankcase gases go out the fresh air tube... and when that freezes... blows your seals). All of those catchcan ads you see on forums are only telling part of the story when they say "LOOK HOW MUCH WE CAUGHT!!!11!" when they show off the fluid, because the fluid is a mix of water, gas, and oil. Gas and water you don't typically care about because they burn off when you drive, but the oil is what causes the deposits (the proper way is for those catchcan companies to actually heat the fluid so that only oil is left).
no, I do not see dual as increasingly common. most car brands have GDI. so which engines and cars have direct+ported injection engines?
It’s really not common. Toyota and some fords motors a mpi rn and certain Audi engines.
What about the VW 1.0 TSI engine...the turbocharged gasoline engine with direct injection... Is it known to have carbon buildup on the inlet valve?
Can't tell you how happy I am that I found your channel. You explain things so incredibly well. You've opened up a whole new world to me thank you!
VW 2.0TSI engine owner knows the carbon build up problem. At +/-50 000miles theres a 2mm. crust behind the valves causing cold start missfire. Hope VW will change to PI and DI combo soon :)
EA888 Gen 3 has both port and direction injection.
You can just buy a oil catchcan and reduce the problem.
And if VW's TFSIs actually met Toyota's specification about valve clearance from the 1980, then you would have less oil on your valves too.
By the way, if you don't drive your car for a while (like weeks to a month) then the carbon deposit can dry out and flake of, these flakes CAN get in your engine when starting it again.
p.s. I said "can", not "will". But engine builders say that if you leave an engine disassembled for a week or 2, the carbon fall off as soon as you pick up the valves standing on your desk.
How about 140k miles on my A3 and no issues. At least for now...
I show seafoam and crc vs direct injection
@@ianpolo5673 Is there a list of PI+DI engines?
How about using oil catch cans on D.I. engines to minimize the ill effects of blow-by ??
Could you do a video about this ?
VALVE GUNK!!! I show crc & seafoam vs direct injection with the worst intake valves from carbon buildup so ee is correct
So if you want to see what cleaners work and what doesnt check it out
Talks about carbon deposits: has flash backs of caked BMW valves and intake manifolds 😩
ICE is so clean and efficient these days! Considering what they were like with carburetors these modern engines are almost miraculous. I wish the EPA would back off and stop raising the bar.
D4-S training talks for my job specifically mentioned carbon buildup. D4-S has an injector cleaner cycle that shoots a high-pressure air-fuel mixture laterally across the notch in the injector tips to clean them. It happens during idle every approximately 17k miles.
Got a real laugh out of the Moe for Molybdenum, I have a feeling you're pulling our collective leg there. As a mechanic my eye went immediately to the right side of your white board. I was bouncing out of my chair until you mentioned valve deposits, the bugaboo of DI! Ask anyone who has had to have their BMW's DI intake valves blast cleaned how big (expensive) a problem DI resultant intake valve deposits can be.Always enjoy your videos. If you weren't kidding about "Moe", well chem wasn't my strong suit either.
This video makes me wonder if Atkinson cycle DI engines might avoid carbon buildup issues because they force gasoline into their intake runners, where the gas can clean the valves. Perhaps this could be a video in the future?
Title should be.....Why Everyone is Following/Copying Lexus???🥳
Why are the Pistons all angled to the left for all strokes?
Those are the CNN pistons. In the next video we might have Fox pistons?
*Connecting Rods
To minimise the piston slap during combustion. Because due to force it change can position. It’s a kind of offset given to the piston
I wonder how clicky those engines get with twice as many fuel injectors doing their thing.
Mine sounds normal as during idle (when you will hear them outside the car) only one set is used at a time. You can hear the change when it suddenly switches from one to the other as it warms up, but overall it's no noisier than any other fuel injected engine.
At about 5:15 you mention that you start injecting fuel (port injection) during the exhaust stoke when the exhaust valve is open and the intake valve is closed. Would this not just have the effect of spraying fuel on the back of a closed valve?
Roger Saumure Yes. The fuel pools on the back of the hot valve briefly before evaporating.
So a engine with both PI and DI would be best keeping valves cleaner etc ?
How about elaborating Mazdas approach on using heat to prevent carbon?
Damn... the white board got upgraded as well. Best part of port injection is the intake valves got cleaned
Which manufactures have the best DI engines for low carbon build up.? You said some do yet you did not mention the manufactures.
is it true that the Porsche 911 boxer 6 engines have direct injection but the injector is positioned so that the mist hits the intake valves??
lexus already knew about carbon build up of DI only design, that why when they released their flagship sedan 13 years ago, both DI and PI is used on their LS460. As the LS460 needs to be their most reliable model.
I have a 2008 GS 460 with the same engine. Decent gas mileage and clean valves. Not sure if it works like the D-4S though.
what about the ES?
@@bullzeye1423 I think the newest 2GR have the D4-S. The older ones are port only.
what kind of fuel injection system does the newer toyota corolla use pls answer
White Board: Bigger, Longer & Uncut
Suppose that’s why Ford added port to the ecos. But to be fair carbon build up isn’t a big issue for most people… some people will melt down with that comment but it’s true. Just drive. Change your oil 5-8k.
Use top tier gas. Ford people are installing catch cans to collect crank case blow by. Lets not forget drilling a hole in your turbo Intercooler intake to drain fluid from you turbo intake air. Lets not forget 1.5 liter Eco boost 2016 to 2018 that loves to put coolant from the head gasket to the cylinder. Can watch videos of Ford Eco boost pickup motors rebuilds all day long. and then watch Ford Eco boost rebuilds because the first rebuild was done wrong. Or watch "Ford Boss Me" videos that says change your synthetic oil every 3,000 miles or else. Beats me why people are lining up to buy Mavericks and Broncos with Ford's track record.
The legal department likely advises engineers to not mention the fact that the engines they are developing have inherent flaws in them and as a result could open them up to legal problems and possible settlements.
Ha, probably the real answer! And yeah, I would assume it's because they sell engines with purely direct injection, or plan to in the future.
Do carbon deposits end up as solids after combustion? What does this do to turbochargers?
Great stuff as always Professor👍
Thanks!
@@EngineeringExplained Is there any other brand than Toyota and they D4-S who are using double injections direct and port ? Never heard anybody else doing that, since Toyota introduced Its D4-S.
@@djorksolo8544 VW is using it on the EA888 Gen3 2.0L TSI engine sold outside USA
@@MrNangu Ok good to know! But compare to Toyota It's only 1 engine in VW. While Toyota already many engines. So I would go for a Toyota rather than a VW which isn't reliable at all!
@@djorksolo8544 Yes, It's your choice. I only answered your question ;)
A lot of engine oils have Molybdenumdisulfite as an anti-friction additive.....
Now guess what that "Mo" stands for and how it gets onto your valves....
I have two questions:
-for a PI+DI do you need two differentes fuel system of differents pressures ?
-does that work with diesel engine cause diesel only uses DI right ?
single source, the DI injectors are driven by a secondary high pressure pump that is mechanically driven off the cam. In DI only it's the same way actually, 2 pumps.
As they said one system, two pumps.
But if you have a diesel engine you can get many of the same benefits with even more efficiency by using a propane injection system that puts propane in the intake system and causes a more homogeneous charge of fuel to be burned by the diesel fuel when it is injected. Then the diesel fuel becomes like the sparkplugs controlling the timing of the combustion.
@@davidscott5903 You're right, except methane is actually better for diesels.
A diesel engine can work on 45% propane/butane and 55% diesel, OR it can work on 10% diesel and 90% methane.
A diesel engine that runs partially on methane will have increased power output and decreased emissions because of the homogenous a/f mix.
The only drawback is that you need another tank to be placed in your car/truck and you need the system to be setup and tuned in. That's not to big of a deal when you factor in propane, butane and methane are all a lot cheaper than diesel.
@@sasjadevries
The only reason that I mention using propane is because of the availability of propane in the USA, and the fact that it is in liquid form in its tank. I didn't know about the amount of difference in ratios. Do you know the reason for the difference? I would like to know if you can find out. Thank you.
The 3.6 DI engine from gm has the carbon issue bad. Had it happen in a 2010 enclave in 2018. Steer clear of DI without port injection.
How much did it cost to have the valves cleaned?
He forgot to mention Mazda engines run the intake valves at 700 degrees to burn off carbon deposits on intake valves. And he didn't mention oil catch cans can capture the blow by. Maybe someone can make an EGR filter now too. I love how electric cars don't have any of these problems though. I'm just waiting til an electric car has a 600 mile range!
How do Kia and Hyundai tackle this problem I can’t find any solid information on it. They don’t seem to be having any problems with DI.
@@tails300 good question. I'd like to know as well. I know Ford and Toyota have engines with both port and direct injection. Not sure if any other manufacturers are doing that.
I believe my 2021 Highlander has both the port and direct injection. Glad to see Toyota is the industry leader.
Toyota DS4 has been on the market for at least 8 years
Saw the title and thought:
Whiteboard video!
Tx!
Is there a list of vehicles that use both port and direct injection?
I'm learning so much from these videos. Have been for years. Thank you Jason!
Great explanation. I wish I knew how my Coyote chooses to utilize both its port and direct fuel injectors, and at what RPM ranges. Thanks for your excellence once again on the whiteboard!
Me too.
Ein wunderbares Video, vielen Dank für ihre Bemühungen, ich habe viel gelernt und bin immer noch erfreut darüber.
Honda was doing something very similar to what Toyota is doing but with carburetors back in the 80s. Look up Honda CVCC engine
well before the world war erupted honda and toyota are business partners
Which company engines are available with port+ direct injection system in 2019(India)
Hello, First of all thanks for sharing video. I do have few query, appreciate your reply
1. Does this video is apt for gasoline only or for CNG also.
2. In PI, during injection of fuel it will displace incoming air thus affecting volumetric efficiency, considering Atkinson cycle.and thus less power will be produced.
manish mishra Yes, in CNG there is a displacement of air in PFI, but the required pressure for DI is quite high which usually needs a high pressure fuel pump. Usually this is done only with LNG. Westport Power does a dual fuel (diesel plus DI LNG) which has one of the lowest CO2 for a combustion engine. Generally for SI engines, though, turbocharging is cheaper than DI for CNG and that is what most engine manufacturers do for CNG, though some don’t turbocharge but instead raise the compression ratio to roughly 12:1 and the efficiency improvement can offset the air charge loss from fuel displacement. The air displacement for petrol PFI is lower than the air density improvement from cooling, but this is not the case with CNG which has roughly 10% air volume reduction.
Could this be one of the reasons cars are getting LESS, and LESS RELIABLE?🤔
It's definitely one of them, and also adds to to overall maintenance costs.
@@R777-RLM Totally agree with you! More moving parts=more change for stuff to brake
Never go full direct injection. Only buy combined injection or port injection.
Back in my day people use to spit homogenous fuel mixture in the air intake just like you see in Mad Max.
what manufacturers use both injection methods?
I just realized you don't wear the ring on your pinky finger, how are strangers in public supposed to know that you're an engineer??
Or drive a volvo
Wasn’t it Saab’s they drove back in the day?
@@fourtysix4646 that too
@@fourtysix4646 thought that was dentists
Obviously depending on the application, it seems as though you get the best of both worlds with Port + Direct Injection, thank you for the explanation on all of the variants. It trips me out that all of these ways to inject fuel were all from the minds of engineers. It's pretty rad if you ask me.
I propose cleaning up the blow-by gases and venting them outside. Problem solved.
Can you compare am DI engin that doesn't have the carbon problem with one that it has.
Two main questions: what cars with direct injection do NOT have carbon build up problems and why/how?
Thanks for tackling this, Jason. I have been curious about some of the specific techniques used in the D4-S system on my FA20 and found there is little info out there. Wherever you got this info thanks.
This is the first time I know about positive crankcase ventilation. Thanks man
Hello! Big fan of your videos. One thing got me curious, for more power isn't it better to use port injection at high rpm? My thought is that direct injection is limited by it's opening time. As far as I know Vw 1.6 fsi engine is ok at low rpm and it's quite torky, but at high rpm is not brilliant... a port injection engine may be not so efficient but for power it's more useful (ex: Lamborghini Aventador v12 6.0 mpi)
We don't want no Mo.
Do Mazda DI engines get a lot of carbon buildup? I wonder if their new skyactiv X engine will run into carbon buildup issues.
Stewart Morley they do if you run the car mostly in the city you can have bad deposits even at 30 k miles.
2gr-fse. Love my 2gr-fse in the is350
The 2GR engines are gems
Are those the ones with the loud injector ticking
@@jackb6794 Not sure about the 2GR, but the 1UR-FSE is quite noisy.
jack GB the valve lifters can get noisy sometimes making a ticking or tapping noise when in park or idling at a red light but its really only once in a great while it does it. The gx460 though with the 1ur-fe is notorious for it (like the guy above me says)
And don't forget throttle body injection! That one was probably the most revolutionary of all... And there were electronically controlled carburetors, with oxygen sensors. And my favorite, mechanical fuel injection. ;)
More and more complex... the end of gasoline cars is getting near
Electric motors are far more simple mechanically. :)
Gonna guess before watching. Is it to reduce or eliminate carbon buildup by the valves?
Also better mpg
Also more power
Engineering Explained, and Savagegeese reviews, are the only ones I have seen address the problems with Direct Injection and carbon build up. Some vehicles have severe build up as early as 20,000 miles, they then have to spend about $1,000 to fix it, until the next time. Hopefully Dual Injection will become standard in the future. Until then, some Toyota's and Ford's F-150's have Dual Injection, or a few still have Multi-Port, like Chrysler/Ram.
In the future? It already is a standard. Only some very low end models are still MPI only. The worst carbon deposit problems I've seen so far on the internet seem to be on turbo engines
That's because carbon build-up can vary from engine to engine- and yes, that means not every DI engine has valve deposits. Most newer engines are utilizing a sub 1 micron PCV oil separation system, which in most cases is sufficient to keep intake valve deposits away on DI engines. There are a couple of systems out there, you can youtube search "Dana Multitwister" for one type.
As a mechanic, I've noticed my wife's Mazda2 Skyactiv engine doing its retarded timing catalyst warm-up cycle too.
The car sounds cool, it's got a gruff, slightly raised idle speed like a poor man's world rally car!
It is linked to the wheel speed sensors, so if we roll it back down the driveway during warm-up it cuts out & returns to a normal quiet idle before you drive off.
Dangermouse Usually these days they will use a software model of the catalyst temperature to switch the catalyst light off mode, at least that’s what my software does. On cars with this algorithm if you drive off that mode kicks out earlier than if you just let it idle.
@@dale116dot7
Yep, confirmed 👍
Good job on this vid. I never nod off watching your stuff. My solution for my new 3.6 V6 was a catch can and you should see all the crap it catches, none of which should be ingested by any engine port injected or not🤮
Thanks for the video :) really explained a lot. Wonder if the whole DI issue is the same for diesel engines? I've never experienced modern Diesel's torque (been meaning to for years 🙁) but we have an old Peugeot 405 indirect injection turbo diesel which has decent torque compared to most modern cars here; the 1.5 liter petrol engines in Toyota Allions, Premios, and 1 litre Indian cars; and has lasted 25 years without any major engine repair... I wonder if modern diesels would last like them
Molybdenum
k I'm just showing off, but I don't care. I loved chemistry lol.
So from what I understand is port injection is the way to go. Deposits are reduced by a landslide but still possible from the image shown in the video. My question is will an engine still benefit from an oil catch can or oil separator even if it’s port injected or is it overkill and not necessary? Thanks in advance!
Would've liked to see a description of the VW TSI dual injection system and not just Toyota
I hope that VW brings the 1.5 TSI Evo with both types of fuel injection when the Golf Mark VIII comes to Canada.
Manually cleaned the intake ports/valves my 2010 gti twice... I wish VAG brought the euro motors over to the US because those came with 2 sets of injectors (like in the new rs3)... Whether or not the car has a dual injection system will influence my next vehicle purchase.
Jason R I have a 2016 GTI 2.0 turbo and it came with a dual system.
@@dale116dot7 you must not be in North America. The North American market only received the single direct infected fuel system; no port injectors.
Hey. Is it possible,or do they do this already. Ok. So idk much about cars or how they work. So please don't make fun. I watched your video but could only follow so much. Now I know they spray gas into the engine. My question is can they or do they harness the gas fumes and send it separately to the cylinders and if so how. And if not why not? Wouldn't it be basically free fuel? Possibly being able to just start the car,or idle the car, or give it a power boost? Again,I'm not a car guy and never given them any real thoughts. But I'm guessing the fumes are probably not being utilized efficiently and if you could create a system to gather them and distribute them appropriately, wouldn't it improve the average car? I might seem like I'm not very smart ,but I love inventing and fixing problems. I didn't go to college and have zero experience in this area. I just think about a lot of things and hope to become an inventor one day. I don't have anyone to talk to about this. But yea, any feedback would be cool.
This video was very well done for someone like myself fascinated and curious about the internal functionings of the combustion engine but not a full on gear head by any stretch of the imagination. I gotta subscribe so that I can learn more! 😉
@Engineering Explained I wonder how the "D-4S Injection" in all Toyota's newest engines, such as the one found on the M20A-FKS (corolla hatch), work to reduce the carbon build up on the intake valves... they state it has a "low-pressure" port injector unlike the higher power port-only injected engines of yesteryear. I know that the 2UR-GSE (Lexus 5.0L V8) had both port and direct injection as well upon its inception, but they never specifically called out the port injector to be "low-pressure". I know many ISF owners whom have viewed their intake side and upon inspection for carbon build up noted there to be very minimal amounts if not nearly any present; as crazy as that sounds. I'd be curious to see if Humble Mechanic would also have an opinion on this. All this to say I'm not sure if Toyota even got it right, as at least on my e210 hatch with the above engine I'm experiencing cold start misfires indicative of carbon DI issues.
moooo!!!!!!!!!!!!! its Molybdenum, love you broo......keep up the work. good knowledge..thanks
Thank you for this informative video about DI and PI engines. Could you also do a video on how to reduce or clean carbon deposits on DI engines? Much appreciated!
TLDR: To avoid carbon build-up on the valves while retaining the benefits of GDI.
Hi, great clip, but i have few questions. Maby it depend on car brand, but do PI and DI its own map in ECU? Also, if you check wolkswagen engine EA888 3gen. and 3gen+, they used dual injection on engine CJEB, but on newer version 3gen.+ its not used anymore. Do you have ideas what are cons to use it?
Carbon deposits. Why I don't own a V8 S8 or V10 S6/S8. :-(
This video makes me think of Ford 2.3 EB ranger/mustang/explorer engine is only DI. The 1st gen 3.5 EB was DI only now the gen 2 3.5 EB is PFI/DI along with 2.7 EB. They will never tell you about the carbon but slowly all their motors are changing over even the 3.3 non turbo v6 has both injection methods.
Thank you for this video. I am a long time subscriber. I just bought a 2018 Hyundai Sonata Limited with a 2.4 GDI engine as a family sedan. This car currently has 16,000 miles on it. I really want to take car of it, as I payed cash and have never owned a car this nice in my life. Do you have any recommendations/videos on Mitigating carbon deposit issues on the intake valves? I plan on replacing the PCV valve every 20k miles. I really appreciate the effort and diligence you put into your videos. any help would be greatly appreciated.
Is this normal to carbon buildup which is dry in exhaust tip in (petrol) gasoline Toyota yaris sedan 2019???? car driven only 4000 miles
In my finger little amount of dry black carbon came out when I touches the exhaust tip ....
Please reply
Very awesome video! This made me super happy to hear when Toyota was pushing the D4S dual injection system because it is so efficient. You get the best of both worlds without being stuck with the compromises of DI.
Hello
Can a mpfi engine be converted to direct injection?? If yes which company does and the kit??
And
Can a GDI engine be fitted with CNG kit?? If yes which company??
Kindly send links if possible.
Are there any manufactures that only use port fuel injection system? I'd rather stay away from any direct injected systems because of the cost ,(labor, parts, time down, money), to remove the carbon buildup on the intake valves.
Direct injection reduces knock. Isnt this the same term some use for detonation which is bad? And happens alot more on direct injected due to higher compression and carbon buildup? Surprised the DI crosstrek you have hasn't had this issue yet. My motor spent its whole 25k miles of life in the lower rpms driven slowly. by 15k it had such bad carbon buildup causing LSPI that Subaru condemned the motor and told me drive it till it goes. Sounded like bolts in a glass jar being shaken.