Oh how I long for the days of plugs , points ,Carburetors . Life and engines were so much better in every way. Thanks for the great sharing of knowledge. Very good and informative.
One thing to mention for those who couldn't find a vacuum leak but idle is still rough: Clean maf/map sensor, check spark plug gap and overall condition and check coil packs. The last is harder than the rest but sometimes even visual inspection can tell that they are busted: the core can look burned or wire connection is loose/broken. More sophisticated way is to test them with multimeter. Next step I would say will be fuel injection cleaning. And if your car has fuel filter built in fuel line then replace that. It's cheap and relatively easy job.
The video isn't about why your car has a misfire. The video I watched was about how to find a vacuum leak. He has videos about fixing a misfire. try to keep up .
You're a god! Not only was this video incredibly informative and well-explained to someone (me) who is hardly a mechanic, but it helped my son and I find a leak associated with the PCV valve in his 1986 F-150 truck - the day before he goes away to school.
How can anyone give this guy a thumbs down?! The cause and effect explanations are wonderful. RUclips has changed the world for the better and you are part of that. Awesome Dude!
Man iv been trying to figure out my problem on this 2010 mazda 3 for almost a year now and watching your video helped me learn my issue is a vacuum leak. From me running it that long result in engine failure ? And i replaced the spark plugs and MAS sensor recently. Haven't found the vacuum leak yet but thanks to you i am now blessed with honest knowledge ! Much appreciated
Great instructor: detailed information on type and severity of vacuum leaks with differing symptoms, associated systems, causes, and tests to use. Awesome.
As a technician of the electronic repair persuasion with foot-steps in alot of different areas over the last 30-yrs, this guy knows what he's talking about - the quick tutorial on using a small propane-supply versus starting fluid is SPOT-ON. I'm watching and learning here too :) Thanks R&W Guy :-D
Very appreciative of the explanation on vacuum leaks. Had a rough idle on my 2009 Honda CRV. Started looking for leaks, didn't notice any hose problem until I removed the manifold top cover. Then found the leaky hose right on top of the manifold.
You know your videos are so much better than others because you cut to the point and explain very carefully and in a sense that others can understand and listen too. 1 out of 10 I would say your vids are 8.5 to 9.0 that's really high up. Good job. My 350z has a lot of new mods and I have lots of vacuum issues from bad torque sequencing and over seen loose hoses. So I will try you method.
Dude!! U rock!! This helped me sooo much. One thing you should mention in the video though is that a vaccum leak can effect youre brake booster if its large enough. My brake pedal wont come all the way back up when im going beyond 40mph. I have to stick my foot under the pedal and tap it back up. I couldn't figure out where the leak was so im really glad I seen this video. Thank you
Awesome methodical explanations! Not just one sentence answers but explaining why and how each effect causes and effects other systems and simulating the problems! Thumbs up!
@@javierherrera8782 Your replied question was written as a phrase and vague as well. Why are you attempting to teach ppl grammar on a Comment page? Especially when our presenter is doing such an excellent job of instructing us in finding and repairing our rough idling engines!
I have watched all of his videos i believe. He is in my opinion the best source for automobile info. Very easy to follow and understanding of the entire subject. YOU are the BEST.
Best how to find a vacuum leak video. You saved me a lot of time. Sounds like my truck has a large one. Rough idle at stops, sluggish at speeds under 10mph.
No, you don't want soapy water to get sucked into your engine, thats why he's using starting fluid, not water, he does not risk his safety for nothing.
totally agree , water and soap in engine bad. also method is very finite in its uses. water naturally drips off so and hose or area where the water or sight to that water is difficult will not be effective.
@@huyvuquang9533 the only problem about using starting fluid is if you use a lot of starting fluid it can burn out your heads it's not good for the heads
Thank you for this, because you went through and showed the symptoms of different types of vacuum weeks I was able to figure out that I had a large vacuum leak, and a simple inspection of the large intake hose revealed a crack right at the connection, you saved me hours of time and frustration with your video. So thank you very much
The safest way to find a vacuum leak is a smoke generator. The "store bought" ones are mighty expensive but there's lots of " homemade" ones on here that should work. I've never needed one so, best of luck on it! They work on a hot or cold engine and there's no chance of fire. One thing most people overlook is a leak at the fuel cap. If you need to replace one, buy OEM because the cheap store ones don't always seal properly. If the leak is bad and your vehicle is newer, you will get a check engine light. Get the code read at any national parts store for free, or just check the cap first. You have some great tips on all your videos! Thanks for posting them!
Arkansas Man there is a lot of disagreement about this but some say a bad or incomplete sealing of a fuel cap can give a P0171 code...is that what you are saying ? After changing both o2 sensors , MAF, the PCV valve , I’m still getting the P0171. My gas cap keeps spinning if you keep turning it but o keep reading that it has nothing to do with that code . I am not sure if my shop has actually done vacuum leak tests except visually . Are smoke machines a pretty standard machine shops use to test for leaks? I’m reluctant to keep spending money on just replacing more parts only to find that I’m still getting the code. I’m broke and the second mechanic has only done visual inspections of all the hoses and lines as far as I know and didn’t find any obvious leak except and bent PCV valve which he replaced and still the service engine soon light came back with the OBD saying running lean. Frustrated .
If you answered, I would be very happy. I’m curious how the vacuum leaks hook up on my truck. I swapped the whole power train into an f250 xlt lariat. I did everything you showed. I changed 02 sensor, spark plugs, spark plug wires, coil, and distributor. Changed the fuel filter and I got my other map sensor from an 1991 f150 custom that’s the old sensor and cleaned it out. Everything is good, runs like crap. Can barely run on 500 rpm and will die. Used to run on 1.5rpm and would rough idle. Change the vacuum lines and it made it run on 500rpm. Have to give it gas to make it not die or it’ll just backfire. We took the smog pump and Emissions off and don’t know if I should hook some of the lines to vacuum lines so the Ecm knows it’s off and doesn’t read a false reading. The fuel pressure is really good, but it backfires still. I don’t know if I should change the vacuum lines for try to find vacuum leaks. The motor sat for 10 years and it sat out in the winter for a year before we got it into the other truck. Changed the water pump/oil pump. The intake valves could be rusted and stuck. I just don’t know. If anyone knows what it could be, I would be happy. Engine is a 1991 4.9l 300c i6 from a ford f-150 that is my grandpas old truck, I put it into a 1989 ford f-250 that had a 460 v8 in it. Your video makes me think it could be something simple, but very hard to figure out.
You can take two plastic bottles, cut one in half, cut two holes in the second with one in the cap, then you can light a cigarette put it in the cap, screw it down, put the other bottle over the lit cigarette then blow air into the bottle with an air gun to create a smoke machine, you can connect the cap of the second bottle to a tube and connect it to your vacuum system. This way you can see any vacuum leaks you have when you see smoke coming from a tube or fitting.
Good info. I bought a car with a known bad egr and put a new one on. The result was still erratic cold start revs but at warm ran like silk. Took car for a test drive and wow the whistle of big vacuum leak. I think it is the silly Idea of rubber rings and plastic upper intake manifolds on V6 engines.
1991 Lancer GTI 16v, lumpy idle. Other than that, car runs great for 31 years, and the sport clutch and recently cleaned throttle body plate really makes it wanna go, very responsive 4G67 engine. ❤
best video I've seen on vacuum leaks. well explained. thanks,it really helped me. first time I see any of your videos and i already subscribed and consider me a fan.
I attempted to use brake fluid. I turned the engine on and started spraying anything that connected to a vacuum hose. The speed of the engine never changed. However, I did see a bunch of smoke coming out of the exhaust. Then I revved the engine until the smoke cleared. Then, I went step by step spraying different places and checking for smoke. Finally, I found a massive separation in the corrugated portion of the mass air flow sensor air boot. I ordered one. Thanks internet.
This video helped me out so much. A shop did some work on my car and they had to remove the air hose attached to the intake. They didn't tighten the clamp enough, and once I found that, tightened it, then turned on the car, and it roared back to life.
HELP - Your videos are AWESOME ! I have a 1994 Chevy 1500 giving me a lean code 44 yet it fails inspection because it is too rich(High HC and CO)...I have replaced the catalytic converter, the EGR valve, the o2 sensor, the spark plugs, intake manifold gasket( vacuum leak), changed the oil. and fuel filter...After 7 minutes, the check engine light comes on throwing the code 44. Dry compression was 175 to 180 on all 8 cylinders. PCV valve is good, MAP sensor is good, Throttle Position sensor is good, new o2 sensor is good all of them with correct voltages when bench tested. I even used Sea Foam and another guaranteed to pass bull crap and nothing... I can't find anymore vacuum leaks either via smoke test. SOMEBODY HELP ME PLEASE !!!
I replaced the timing chain and the check engine light still came on after 7 1/2 minutes. A week later I pulled the break booster check valve from the break booster leaving it intact in the vacuum line and capped it. The check engine light came on at 12 minutes. I killed the engine and stepped on the brake several times really hard to test the break booster and it worked properly. I uncapped check valve and reinserted the check valve into break booster gromit then I started the engine and the brake peddle went down like it was supposed to because of the vacuum assist. The check engine light still came on. I gave up again angry. I let it set a couple of days then had to drive it 100 miles and noticed the light didnt come on. I immediately got it inspected and it passed with flying colors ! I don't know if it was the replacement of the timing chain and the computer just needed time and mileage to reset or me jacking with the break booster that fixed it, but it's DONE ! Hallelujah ! It took two years and my gas mileage went from 12.5 to 16 mpg !
Thanks! You really explains this process in a very easy understandable way! It was very helpful to me! Im going to try this and save me some money. I was just going to have my Oxygen sensors changed. Thanks to you and RUclips I can do some checks myself. Thanks again! Great job!
Super useful!!! My '95 Contour has idled rough and low since I bought it for $500 fifteen years ago. I'd like to fix it (finally!) and this video gives me several things to try.
As you showed in the video, the large diameter section between the air filter and intake manifold is a frequent offender. Also, if you've just finished fixing something and are having issues, retrace all your steps/work. Chances are it's something you did during the last repair. Don't ask!
Use carb cleaner/starting fluid to spray around all vac hoses and intake areas while your car is at idle, if idle speed ramps up asap, then the last place you sprayed will be your leak
@@myRatchets hello brother, i changed valve cover gasket of my 2002 corolla and after replacing i road tested my car it was all good and then i parked it for three days and after three days i started it and found it misfiring on all cylinders with check engine light flashing with p0300 and p0301&2 &3 &4 codes.....all vaccum lines i removed were connected back...... please help
@@letmethinkv Not to brag... I have two cars Hyundai and Honda. Hyundai is like my backup and I use in case my old Honda with 277,000 miles won't run. Okay, not running for three days makes it hard to start b/c I believe the distribution of oil in the engine is not good enough. I ounce started my Honda it started but the engine vibrated like crazy... like telling where I have been and not using her for so long. What I do is run it for 5 or 10 minutes once a day whenever I plan not to use it for a while.
Another thing to know is always feel your intake hoses if they feel hard they are already rotted and won't hold the air pressure air will slip out so check your hoses make sure they are soft and flexible
Wow. That had to be the most informative video and I will add NOT a booting drawn out thing, that I have seen in a long time! Very nice job, thank you!!
Thanks for the video. Can i use lysol spray instead of starting fluid? Lysol is flammable, but not super flammable. That way, it might be more safer than working with starting fluid, if u know what I mean. Thanks
Thanks for this vodeo. I am fighting a PO300 error code on my nissan pathfinder 1999. As you know, this is the one of the most complicated error codes that can happen to any car, which I gave it a name "" horrible 300"" . Also, it gave me a headache. Many error codes came up and I was fighting one by one. The last one was PO300 which can be 10 or more different things to look for. Fixing and checking a lot of components I was able to get to the one which I haven't noticed earlier and that is PO303 which means cylinder no.3 off. I tried to clean the injector but I ended up buying one which is unbelievably expensive $ 100. I replaced the injector and engine still hesitate to accelerate , also , engine idling poorly like it will turn off. So , I took of the plenum and disconnected all plugs and hoses . Tomorrow I will continue to connect everything and anything to find the error in this misfire code. Thanks to your video, you gave me some ideas what to check and how to do it properly. Any suggestions, please reply to help me so I can finish this to go to try to pass smog / emission test so I can finally get registration for this car. Thanks once again. BTW, I replaced , EGR, valve, Distributor cap, changed oil, air filter, spark wires and cables, .
Great video. I’m having issues with my HVAC system mode control (vacuum-operated), it’s not working even at idle. Probably an issue on the cab side of the firewall. I’m trying to watch a bunch of different videos to bang vacuum systems into my head.
Honestly when I first saw the video I almost selected a different one but he started talking, Within a few seconds I was completely understanding what he was saying and I have a very small understanding of the combustible engine in general terms relating to it, it meaning Anything under the hood. He really is awesome at explaining and showing.
i know this is old but i have the same engine and im having that engine rattles during idle. same as the one you did when you removed that small hose on your first demo,. now i know what to look, doesnt raise my idle, but i think i have a cracked hose that lets a little bit of air in the system... THANK YOU!
Hello, I always liked your way of explaining things! Thanks for your time and effort. I am having very weird issue, no rough idle, no hesitation, no stalling nothing, the car drives perfectly but I keep getting P0410 code and long term fuel trim is about -14 at idle and goes back to -9 when accelerating. Ive already changed the secondary air pump but the code is back. Any suggestions?
some vacuum hoses are dealer only, odd size etc... some can be a lil pricey, a pain to find etc... for those or any hose you need to fix quick & easy is to wrap them properly with silicone tape. You dont need to the clean the hose except maybe if its very greasy. This Tape doesnt stick to the hose, it bonds to itself. Stretching the tape as you wrap activates it. Spiral wrap the tape, over lapping itself (if the leak is under more pressure use more tape & spiral wrap tape with closer turns) hold it for about 30 secs so it can cure well. You can use a zip tie on ends to make sure it wont unravel if it isnt fully cured. I never leave the house without silicone tape
I use water to find vacuum leaks. Not quite as effective as starting fluid, brake cleaner, carb cleaner or propane, but free, will not damage components and will not cause a fire.
spraying water mist into an engine compartment full of electronics and electronic sensors just isn't a very smart idea. Not dangerous, but can very easily short out these very sensitive devices.
Thank you after seeing this video now i can confirm i have a leak what u mention explains my car symptoms when i take it it for a drive it start to stall and dies but it starts right up
Love your videos and I'm thankful you take the time to do them. I have the same problem with a very rough idle and a major leak somewhere, but the system is trying to point me out to the EVAP system. The vehicle is a 98 Mercedes, would you have any advice to give me on how do diagnose the evap system. I will appreciate any feedback and thanks again for all the videos!
Thank you for this video I am actually having these symptoms on my truck right now and it is causing my map Center the trip and my check engine light to come on and my engine started sputtering also while I was driving down the road and turned off my Stabilitrak and traction control and reduced engine power. I am also having this problem with RPM gauge going back and forth at idle speed my truck actually turned off on me going down the road when I was at a stoplight. Thank you for the video
Genius using propane to find the leak ! Nice job showing examples of minor and major leaks, and what happens to RPM's. Code reader doesn't always give a straight answer. Should have seen this before taking to the dealer (den of thieves) they changed 2 batteries in the 2017 jeep, had a loose connection on a headlamp fixed*, a brake job* including rotors (at 33,000 miles???) Both starred items were wife add ons that were unneeded, and the car still went into limp mode within 1/4 mile of leaving their shop.... All because of a leak in a vacuum hose. which the fixed the following day "at no cost".
Ratchets and Wrenches, I have an 1997 acura cl 3.0 . I had a code which required cleaning out the egr passage ways of carbon. The carbon was caked up with no way for air to get throug. I cleaned out it by using a drill bit but I never removed egr valve. When I sprayed carburator cleaner into the passage way it filled the passageway to the egr valve. After reassembling the intake plenum and starting up the car it began to increase in idle speed going from 1500 to 2500 rpms. Before I cleaned it it maintained a stable 600 rpms. So there must be a vacuum leak. I made the mistake of listening to another youtube post which said it was a common problem with my car and recommended changing the idle air control, which I did and it made no difference at all. Just wasted $32 on a part which was good. Oh well, such is life. I tried blowing smoke in a tube to see if I could see any leaking air which I couldnt, maybe I need to get more smoke in it with a cigar, I tried Old Skool Funks method but proved no leak. Thinking about it and others such as yourself saying vacuum leak causes the increase. This was more of a increase drop , increase drop, constant flucuating continuously. I was wondering could a small piece of carbon from my initial cleaning found its way to my egr valve and kept it from seating thus a small leak from exaust to intake at ilde and parked.
Finally. All in one video that can be used on most of the cars! Thank you. I suspect it's air intake hose in my case (7gen Honda Accord 2.4l. their hoses are prone to cracking during air filter replacement). I fixed it once with duct tape but I guess there are more cracks :)
Awsome techniques, I lost all my hair and eyebrows, my engine blew up. I guess I was a little too sure it was a vacuume leak, But seriously, good ideas!! Loved the video
Oh how I long for the days of plugs , points ,Carburetors . Life and engines were so much better in every way. Thanks for the great sharing of knowledge. Very good and informative.
Well, I don't know about going back to those PITA points...🤮
One thing to mention for those who couldn't find a vacuum leak but idle is still rough:
Clean maf/map sensor, check spark plug gap and overall condition and check coil packs. The last is harder than the rest but sometimes even visual inspection can tell that they are busted: the core can look burned or wire connection is loose/broken. More sophisticated way is to test them with multimeter.
Next step I would say will be fuel injection cleaning. And if your car has fuel filter built in fuel line then replace that. It's cheap and relatively easy job.
The video isn't about why your car has a misfire. The video I watched was about how to find a vacuum leak. He has videos about fixing a misfire. try to keep up .
@@dannyflanagan2681lmao savage my guy
😊
You're a god! Not only was this video incredibly informative and well-explained to someone (me) who is hardly a mechanic, but it helped my son and I find a leak associated with the PCV valve in his 1986 F-150 truck - the day before he goes away to school.
How can anyone give this guy a thumbs down?! The cause and effect explanations are wonderful. RUclips has changed the world for the better and you are part of that. Awesome Dude!
they thumbs down probably because he talked like he has marbles in his mouth
@@stevew278Get your hearing checked, Stevie.
@@ho5zk maybe you and him can enroll in an english class together?
@@stevew278 What’s wrong with my English? I really want to know because unfortunately it’s the only language I know.
@@ho5zk Funny thing is, you didn't make an english mistake but steve made 4 mistakes in 1 sentence.
Man iv been trying to figure out my problem on this 2010 mazda 3 for almost a year now and watching your video helped me learn my issue is a vacuum leak. From me running it that long result in engine failure ? And i replaced the spark plugs and MAS sensor recently. Haven't found the vacuum leak yet but thanks to you i am now blessed with honest knowledge ! Much appreciated
I stalled my car this morning, which is fine whatever everyone does it. Except oh, it's an automatic :P
hahaha
Pro gamer move
😂😂
Ngl you had me in the first half
I did that too first time driving my mustang, when I was test driving it
Great instructor: detailed information on type and severity of vacuum leaks with differing symptoms, associated systems, causes, and tests to use. Awesome.
You truly have a talent for teaching. Out of all youtube repair videos I have watched, you are actually a professional that knows his stuff.
And 6 yrs after this video still the best video on RUclips explaining vaccum leaks .. Great/gold information brother tyvm 👌👌
As a technician of the electronic repair persuasion with foot-steps in alot of different areas over the last 30-yrs, this guy knows what he's talking about - the quick tutorial on using a small propane-supply versus starting fluid is SPOT-ON. I'm watching and learning here too :) Thanks R&W Guy :-D
should engine be running while testing with propane?
Dude everyone of your videos are great!! Helped me in school for mechanics and 5 years later still on my project car! Thanks!
Very simple to learn from. A sincere teacher. Love his “no nonsense” approach…
Very appreciative of the explanation on vacuum leaks. Had a rough idle on my 2009 Honda CRV. Started looking for leaks, didn't notice any hose problem until I removed the manifold top cover. Then found the leaky hose right on top of the manifold.
You know your videos are so much better than others because you cut to the point and explain very carefully and in a sense that others can understand and listen too. 1 out of 10 I would say your vids are 8.5 to 9.0 that's really high up. Good job. My 350z has a lot of new mods and I have lots of vacuum issues from bad torque sequencing and over seen loose hoses. So I will try you method.
Dude!! U rock!! This helped me sooo much. One thing you should mention in the video though is that a vaccum leak can effect youre brake booster if its large enough. My brake pedal wont come all the way back up when im going beyond 40mph. I have to stick my foot under the pedal and tap it back up. I couldn't figure out where the leak was so im really glad I seen this video. Thank you
Awesome methodical explanations! Not just one sentence answers but explaining why and how each effect causes and effects other systems and simulating the problems! Thumbs up!
John Smith affects or effects?
@@javierherrera8782 Your replied question was written as a phrase and vague as well. Why are you attempting to teach ppl grammar on a Comment page? Especially when our presenter is doing such an excellent job of instructing us in finding and repairing our rough idling engines!
I have watched all of his videos i believe. He is in my opinion the best source for automobile info. Very easy to follow and understanding of the entire subject. YOU are the BEST.
This is one of the best how-to repair videos I've come across in a long time. Great editing and video work.
- Dan
Best how to find a vacuum leak video. You saved me a lot of time. Sounds like my truck has a large one. Rough idle at stops, sluggish at speeds under 10mph.
I've also been known to use soapy water to find a vacuum leak which works very well you can tell when it starts bubbling or if it sucks the water in
Sounds a lot safer than the other methods this guy in the video suggested.
No, you don't want soapy water to get sucked into your engine, thats why he's using starting fluid, not water, he does not risk his safety for nothing.
totally agree , water and soap in engine bad. also method is very finite in its uses. water naturally drips off so and hose or area where the water or sight to that water is difficult will not be effective.
@@huyvuquang9533 the only problem about using starting fluid is if you use a lot of starting fluid it can burn out your heads it's not good for the heads
Soap and water is cool for finding leaks but causes your rubber hoses to deteriorate if you don't clean it up afterwards.
this is the most complete video I have found in days of looking regarding vacuum leaks. Excellent work.
Thank you for this, because you went through and showed the symptoms of different types of vacuum weeks I was able to figure out that I had a large vacuum leak, and a simple inspection of the large intake hose revealed a crack right at the connection, you saved me hours of time and frustration with your video. So thank you very much
The safest way to find a vacuum leak is a smoke generator. The "store bought" ones are mighty expensive but there's lots of " homemade" ones on here that should work. I've never needed one so, best of luck on it! They work on a hot or cold engine and there's no chance of fire.
One thing most people overlook is a leak at the fuel cap. If you need to replace one, buy OEM because the cheap store ones don't always seal properly. If the leak is bad and your vehicle is newer, you will get a check engine light. Get the code read at any national parts store for free, or just check the cap first.
You have some great tips on all your videos! Thanks for posting them!
Arkansas Man there is a lot of disagreement about this but some say a bad or incomplete sealing of a fuel cap can give a P0171 code...is that what you are saying ?
After changing both o2 sensors , MAF, the PCV valve , I’m still getting the P0171. My gas cap keeps spinning if you keep turning it but o keep reading that it has nothing to do with that code .
I am not sure if my shop has actually done vacuum leak tests except visually . Are smoke machines a pretty standard machine shops use to test for leaks?
I’m reluctant to keep spending money on just replacing more parts only to find that I’m still getting the code. I’m broke and the second mechanic has only done visual inspections of all the hoses and lines as far as I know and didn’t find any obvious leak except and bent PCV valve which he replaced and still the service engine soon light came back with the OBD saying running lean.
Frustrated .
I have a similar kind of sound in my vehicle. I am not sure yet if it is a leak. Great video. Now I have some idea how to diagnose my issue.
2:16 you’ve already taught me more then anyone has about vacuum leaks. 2 minutes in.
Well done sir.
If you answered, I would be very happy. I’m curious how the vacuum leaks hook up on my truck. I swapped the whole power train into an f250 xlt lariat. I did everything you showed. I changed 02 sensor, spark plugs, spark plug wires, coil, and distributor. Changed the fuel filter and I got my other map sensor from an 1991 f150 custom that’s the old sensor and cleaned it out. Everything is good, runs like crap. Can barely run on 500 rpm and will die. Used to run on 1.5rpm and would rough idle. Change the vacuum lines and it made it run on 500rpm. Have to give it gas to make it not die or it’ll just backfire. We took the smog pump and Emissions off and don’t know if I should hook some of the lines to vacuum lines so the Ecm knows it’s off and doesn’t read a false reading. The fuel pressure is really good, but it backfires still. I don’t know if I should change the vacuum lines for try to find vacuum leaks. The motor sat for 10 years and it sat out in the winter for a year before we got it into the other truck. Changed the water pump/oil pump. The intake valves could be rusted and stuck. I just don’t know. If anyone knows what it could be, I would be happy. Engine is a 1991 4.9l 300c i6 from a ford f-150 that is my grandpas old truck, I put it into a 1989 ford f-250 that had a 460 v8 in it. Your video makes me think it could be something simple, but very hard to figure out.
The three holy mechanics on RUclips. ScannerDan, Eric o from south main, and ratchets.
what about chris fix?
@@chrisj2308 thats what I was thinking
You can take two plastic bottles, cut one in half, cut two holes in the second with one in the cap, then you can light a cigarette put it in the cap, screw it down, put the other bottle over the lit cigarette then blow air into the bottle with an air gun to create a smoke machine, you can connect the cap of the second bottle to a tube and connect it to your vacuum system. This way you can see any vacuum leaks you have when you see smoke coming from a tube or fitting.
Great video! Thanks for the help. I loved the line when you were explaining the propane torch, "Don't light it obviously!" :)
Always very informative and presented straight forward without any silly music .Thank you
Because of your video I found my problem and replaced a leaky hose. Thanks man....very helpful!
This is a massive sigh of relief man, thank you so much. My symptoms match exactly with a large vacuum leak.
I like the way you go over and explain problems. You cover them great, keep it up.
Good info. I bought a car with a known bad egr and put a new one on. The result was still erratic cold start revs but at warm ran like silk. Took car for a test drive and wow the whistle of big vacuum leak. I think it is the silly Idea of rubber rings and plastic upper intake manifolds on V6 engines.
I learned ALOT from this video, Thank You.
1991 Lancer GTI 16v, lumpy idle. Other than that, car runs great for 31 years, and the sport clutch and recently cleaned throttle body plate really makes it wanna go, very responsive 4G67 engine.
❤
best video I've seen on vacuum leaks. well explained. thanks,it really helped me. first time I see any of your videos and i already subscribed and consider me a fan.
Jorge Antrax Almaraz that's what's up
////j7
I attempted to use brake fluid. I turned the engine on and started spraying anything that connected to a vacuum hose. The speed of the engine never changed. However, I did see a bunch of smoke coming out of the exhaust. Then I revved the engine until the smoke cleared. Then, I went step by step spraying different places and checking for smoke. Finally, I found a massive separation in the corrugated portion of the mass air flow sensor air boot. I ordered one. Thanks internet.
Saving this to my playlist. Simply good bananas and a leak in the brake booster would never have crossed my mind in 100 life times.
This video helped me out so much. A shop did some work on my car and they had to remove the air hose attached to the intake. They didn't tighten the clamp enough, and once I found that, tightened it, then turned on the car, and it roared back to life.
HELP - Your videos are AWESOME ! I have a 1994 Chevy 1500 giving me a lean code 44 yet it fails inspection because it is too rich(High HC and CO)...I have replaced the catalytic converter, the EGR valve, the o2 sensor, the spark plugs, intake manifold gasket( vacuum leak), changed the oil. and fuel filter...After 7 minutes, the check engine light comes on throwing the code 44. Dry compression was 175 to 180 on all 8 cylinders. PCV valve is good, MAP sensor is good, Throttle Position sensor is good, new o2 sensor is good all of them with correct voltages when bench tested. I even used Sea Foam and another guaranteed to pass bull crap and nothing... I can't find anymore vacuum leaks either via smoke test. SOMEBODY HELP ME PLEASE !!!
I replaced the timing chain and the check engine light still came on after 7 1/2 minutes. A week later I pulled the break booster check valve from the break booster leaving it intact in the vacuum line and capped it. The check engine light came on at 12 minutes. I killed the engine and stepped on the brake several times really hard to test the break booster and it worked properly. I uncapped check valve and reinserted the check valve into break booster gromit then I started the engine and the brake peddle went down like it was supposed to because of the vacuum assist. The check engine light still came on. I gave up again angry. I let it set a couple of days then had to drive it 100 miles and noticed the light didnt come on. I immediately got it inspected and it passed with flying colors ! I don't know if it was the replacement of the timing chain and the computer just needed time and mileage to reset or me jacking with the break booster that fixed it, but it's DONE ! Hallelujah ! It took two years and my gas mileage went from 12.5 to 16 mpg !
Check the timing.
This was the best video I’ve seen on vacuum leaks especially on how to test the brake booster and valves
Thanks! You really explains this process in a very easy understandable way! It was very helpful to me! Im going to try this and save me some money. I was just going to have my Oxygen sensors changed. Thanks to you and RUclips I can do some checks myself. Thanks again! Great job!
This is by far the most informative and easy to understand video I've seen. Well done.
Super useful!!! My '95 Contour has idled rough and low since I bought it for $500 fifteen years ago. I'd like to fix it (finally!) and this video gives me several things to try.
woww I love that you showed us exactly how it would sound and how the RPMs would change thank you in doing this test right away.
This has to easily one of the best DIY mechanical video I've ever seen. Great job man!
As you showed in the video, the large diameter section between the air filter and intake manifold is a frequent offender. Also, if you've just finished fixing something and are having issues, retrace all your steps/work. Chances are it's something you did during the last repair. Don't ask!
What about using smoke to check for a vacuum leak? Wouldn’t that tell him exactly where the leak is?
Thats how I had one checked for by a mechanic, smoke.
I'm assuming the mechanic watched for smoke movement due to the leak. Is that right?
Use carb cleaner/starting fluid to spray around all vac hoses and intake areas while your car is at idle, if idle speed ramps up asap, then the last place you sprayed will be your leak
@Budget Boost DIY can u make a video on how to do a smoke machine?
Yes but not everyone has access to a smoke machine
Your video was more helpful then all the other 20 I watched
I know nothing about bac systems and now I do thank you
this helped so much .. just made my night
+Trevor Owens Glad to hear, thanks for commenting.
Hell yeah!!! Im a subscriber NOwLol 🤟😃
@@myRatchets hello brother, i changed valve cover gasket of my 2002 corolla and after replacing i road tested my car it was all good and then i parked it for three days and after three days i started it and found it misfiring on all cylinders with check engine light flashing with p0300 and p0301&2 &3 &4 codes.....all vaccum lines i removed were connected back...... please help
@@letmethinkv Not to brag... I have two cars Hyundai and Honda. Hyundai is like my backup and I use in case my old Honda with 277,000 miles won't run. Okay, not running for three days makes it hard to start b/c I believe the distribution of oil in the engine is not good enough. I ounce started my Honda it started but the engine vibrated like crazy... like telling where I have been and not using her for so long. What I do is run it for 5 or 10 minutes once a day whenever I plan not to use it for a while.
Excellent, comprehensive presentation of how to find them in any car .. !
Starter fluid works great. Spray all vacuum lines and when you hit a bad spot, the engine will rev up
I'm so grateful for this video. I was starting to become hopeless but your teaching is wonderful. Thank you!
Great video, minus the fact that I think it missed the “fix” part of it. Super informative, thanks
Ronnie J. Main fix the vacuum leak
@@mrwess1927 🤣
Thanks for the tip. The first method really helped me out finding a leaking egr valve on my 04 forester.
Decent videos get about 1% likes per view. This has about 1.4%. It deserves 5%.
Another thing to know is always feel your intake hoses if they feel hard they are already rotted and won't hold the air pressure air will slip out so check your hoses make sure they are soft and flexible
The gas one is great, good tip im doing this tomorrow.
Great video, quick, simple, informative, NO BLA BLA BLA! Just liked and subscribed!Thank you!
This guy teach me so much I became a machine.Great expectations one of the best.
As an addition... Smoke machines are extremely helpful about $100-200. Was worth it for me on the 1st fix and going on the 6th.
Very helpful and informative video.
Appreciate it..thanks I'll change the EGR valve it's old..stalling in the morning checked everything changed everything..
Thank you man!!!i love how you performed simulations do describe different problems😃😃🤟helped me a ton.🙏🙏🙏
Wow. That had to be the most informative video and I will add NOT a booting drawn out thing, that I have seen in a long time! Very nice job, thank you!!
Thanks for the video. Can i use lysol spray instead of starting fluid? Lysol is flammable, but not super flammable. That way, it might be more safer than working with starting fluid, if u know what I mean. Thanks
Thanks for this vodeo. I am fighting a PO300 error code on my nissan pathfinder 1999. As you know, this is the one of the most complicated error codes that can happen to any car, which I gave it a name "" horrible 300"" . Also, it gave me a headache. Many error codes came up and I was fighting one by one. The last one was PO300 which can be 10 or more different things to look for. Fixing and checking a lot of components I was able to get to the one which I haven't noticed earlier and that is PO303 which means cylinder no.3 off. I tried to clean the injector but I ended up buying one which is unbelievably expensive $ 100. I replaced the injector and engine still hesitate to accelerate , also , engine idling poorly like it will turn off. So , I took of the plenum and disconnected all plugs and hoses . Tomorrow I will continue to connect everything and anything to find the error in this misfire code. Thanks to your video, you gave me some ideas what to check and how to do it properly. Any suggestions, please reply to help me so I can finish this to go to try to pass smog / emission test so I can finally get registration for this car. Thanks once again. BTW, I replaced , EGR, valve, Distributor cap, changed oil, air filter, spark wires and cables, .
by the way, i must say this was an awesome video!! currently trying to track a vac leak (i think) after replacing a switch. i think i broke it :)
Thanks for the info! I am having brake booster leak symptoms. Your video has given me more ways to test booster vacuum.
Thank you for teaching me stay blessed
Great video. I’m having issues with my HVAC system mode control (vacuum-operated), it’s not working even at idle. Probably an issue on the cab side of the firewall. I’m trying to watch a bunch of different videos to bang vacuum systems into my head.
Great video.... probably the most simplified and exact! PERFECT EXPLANATION.... THANK YOU
TRUE
You sir have the best" how to" video's online. TY
Honestly when I first saw the video I almost selected a different one but he started talking, Within a few seconds I was completely understanding what he was saying and I have a very small understanding of the combustible engine in general terms relating to it, it meaning Anything under the hood. He really is awesome at explaining and showing.
Very helpful. Thank you man!
i know this is old but i have the same engine and im having that engine rattles during idle. same as the one you did when you removed that small hose on your first demo,. now i know what to look, doesnt raise my idle, but i think i have a cracked hose that lets a little bit of air in the system... THANK YOU!
Great video. Got a 2002 Crown Vic LX SPORT with 33k miles giving me a 0171 & 174. Have you encounter this and what is most common on this car.
I have the same codes.i am stuck and can't find any more vacuum leaks so I guess ride and die.
awesome video...clear explanation with easy to understand language...and great overview....fixed my vaccum leak in 3 min after watching...tku:)
Hello, I always liked your way of explaining things! Thanks for your time and effort. I am having very weird issue, no rough idle, no hesitation, no stalling nothing, the car drives perfectly but I keep getting P0410 code and long term fuel trim is about -14 at idle and goes back to -9 when accelerating. Ive already changed the secondary air pump but the code is back. Any suggestions?
Wow great video , I learned from this more than I have with 50 to 100 videos .
great video. very helpful. very much info!
lol
some vacuum hoses are dealer only, odd size etc... some can be a lil pricey, a pain to find etc... for those or any hose you need to fix quick & easy is to wrap them properly with silicone tape. You dont need to the clean the hose except maybe if its very greasy. This Tape doesnt stick to the hose, it bonds to itself. Stretching the tape as you wrap activates it. Spiral wrap the tape, over lapping itself (if the leak is under more pressure use more tape & spiral wrap tape with closer turns) hold it for about 30 secs so it can cure well. You can use a zip tie on ends to make sure it wont unravel if it isnt fully cured. I never leave the house without silicone tape
Gracias paisano, your English is awesome by the way. Great instructions and tips.
This may seem dangerous to some people but it’s actually safer than my next method, buddy you earned a thumbs up with that statement haha. Great video
I use water to find vacuum leaks. Not quite as effective as starting fluid, brake cleaner, carb cleaner or propane, but free, will not damage components and will not cause a fire.
It can rust out components.
sirtimatbob It will not cause rust for the small amount of time it will be on the engine. It will evaporate very quickly from the heat of the engine.
Avery Alexander Like the amount of water from a garden house or water from a spray bottle?
jbkaufman water spray bottle
spraying water mist into an engine compartment full of electronics and electronic sensors just isn't a very smart idea. Not dangerous, but can very easily short out these very sensitive devices.
Thank you after seeing this video now i can confirm i have a leak what u mention explains my car symptoms when i take it it for a drive it start to stall and dies but it starts right up
Love your videos and I'm thankful you take the time to do them. I have the same problem with a very rough idle and a major leak somewhere, but the system is trying to point me out to the EVAP system. The vehicle is a 98 Mercedes, would you have any advice to give me on how do diagnose the evap system. I will appreciate any feedback and thanks again for all the videos!
Thank you for this video I am actually having these symptoms on my truck right now and it is causing my map Center the trip and my check engine light to come on and my engine started sputtering also while I was driving down the road and turned off my Stabilitrak and traction control and reduced engine power. I am also having this problem with RPM gauge going back and forth at idle speed my truck actually turned off on me going down the road when I was at a stoplight. Thank you for the video
that was flippin' awesome.
Thank you for the video! This helped me find out whats wrong with my fathers Corolla! The clamp was loose around the big hose!
Good stuff man!
I just had a vacuum line replaced and the symptoms were all as this guy describes. Nice work!
keep it up bro!!..
Hanafi Arifin I will
Genius using propane to find the leak ! Nice job showing examples of minor and major leaks, and what happens to RPM's. Code reader doesn't always give a straight answer.
Should have seen this before taking to the dealer (den of thieves) they changed 2 batteries in the 2017 jeep, had a loose connection on a headlamp fixed*, a brake job* including rotors (at 33,000 miles???) Both starred items were wife add ons that were unneeded, and the car still went into limp mode within 1/4 mile of leaving their shop.... All because of a leak in a vacuum hose. which the fixed the following day "at no cost".
Great video man keep it up!
Sepasgozaram!
Ratchets and Wrenches, I have an 1997 acura cl 3.0 . I had a code which required cleaning out the egr passage ways of carbon. The carbon was caked up with no way for air to get throug. I cleaned out it by using a drill bit but I never removed egr valve. When I sprayed carburator cleaner into the passage way it filled the passageway to the egr valve. After reassembling the intake plenum and starting up the car it began to increase in idle speed going from 1500 to 2500 rpms. Before I cleaned it it maintained a stable 600 rpms. So there must be a vacuum leak. I made the mistake of listening to another youtube post which said it was a common problem with my car and recommended changing the idle air control, which I did and it made no difference at all. Just wasted $32 on a part which was good. Oh well, such is life. I tried blowing smoke in a tube to see if I could see any leaking air which I couldnt, maybe I need to get more smoke in it with a cigar, I tried Old Skool Funks method but proved no leak. Thinking about it and others such as yourself saying vacuum leak causes the increase. This was more of a increase drop , increase drop, constant flucuating continuously. I was wondering could a small piece of carbon from my initial cleaning found its way to my egr valve and kept it from seating thus a small leak from exaust to intake at ilde and parked.
Finally. All in one video that can be used on most of the cars!
Thank you.
I suspect it's air intake hose in my case (7gen Honda Accord 2.4l. their hoses are prone to cracking during air filter replacement). I fixed it once with duct tape but I guess there are more cracks :)
this video is very informative. Thank you for your time.
Wow that was great explanation I feel smarter already!
Awsome techniques, I lost all my hair and eyebrows, my engine blew up. I guess I was a little too sure it was a vacuume leak, But seriously, good ideas!! Loved the video