The cranking waveforms show much more difference between cyl 1 and 5 than the running ones, probably because at low cranking speed there is more time for air to leak out of the cylinder during the compression and expansion strokes. The cranking test also has atmospheric pressure at the start of the compression (due to WOT rather than idle manifold vacuum) so the cylinder pressures will be higher, increasing the amount of leakage. On the cyl5 cranking trace the pressure at the bottom of the expansion stroke is lower than at the bottom of the intake stroke, if the pressure is lower and the volume of the cylinder is the same (piston at BDC in both cases) then physics says there must be less air in the cylinder by the end of the expansion stroke - as there is no combustion you would expect the compression and expansion strokes to cancel out (you take a fixed amount of air at BDC intake, compress it to TDC firing, then expand it again to BDC expansion and end up back where you started....assuming a slightly idealised case where the intake valve closes exactly at BDC and the exhaust valve also opens exactly at BDC). I don't think the pressure trace can tell you where the leak is (inlet valve, ex valve, rings) - just that there is/isn't a leak.... Thanks for sharing the scope data, really interesting to have a look at
It depends on environment that you're in and you're in a if you're in a dealership you have more customers well in the waiting area and I'm waiting for their cars you don't have time to make videotapes you can only do this in private shops where you have one two cars a day
As a first year apprentice technician I love watching your case studies and learning more about the electronic diagnostics instead of just cranking wrenches! Keep up the extremely hard work, we are still extremely grateful 🙏
Wow ! i have been an Electronic tech for over 50 Years and I am so impressed at your skills to understand how these modern cars use electronics to do everything ! The days of the shade tree mechanic are forever gone. If you're successfully fixing modern cars, you understand the electronic components involved ! Kudos to you, and to the handful of techs out there with your knowledge ! I know that you will do well and your videos are teaching many would be techs about what's needed to diagnose these newer vehicles. Love watching your videos and what it takes to resolve problems that did not exist 25 years ago.. Amazing. Thanks ! Keep up the great work..
HiEric I won;t say you missed your calling as you are definetly atop grade mechanic. However you may not have noticed yuar also grade a Instructor. People just seem to understand sometimes difficult concepts easily from your videos. Please keep them coming and say hi to Sheba for me as well.
He's famous and has a huge following and a solid platform, so he made the right decision. I can't name a single Grade A car repair instructor. Can you?
My arthritis began around 43 in my lower back , It's now pretty much everywhere to a degree . We humans are far more fragile than I had ever thought when I was younger . TheReaper!
Rj Aquaponics - That’s a load of nonsense. We’re literally made of animal protein - the most compatible, extremely bioavailable protein for human consumption is animal protein. We need animal protein and fats for proper function of our endocrine system among other systems in the body. The only reason people live, “well,” as vegans is because the body is incredibly resilient and can still survive on almost anything you can feed it. I’d venture to say the OP could eat an elimination diet of solely red meat for a month or two and see improvement in his condition. I’m speaking from personal experience.
@@JosephQPublic Because we are made of proteins, our bodies have a hard time digesting animal protein. It is a constant battle of eliminating the acid loads while fighting autoimmune issues. It is not our proteins that digest the animal proteins, it is our microbiome that makes the animal flesh and fats available. The cholesterol in meats are not the cholesterol used by our brains, we manufacture that type of cholesterol. Bar none, everyone who eats a meat, cheese, milk and eggs diet will eventually grow slower, sicker, weaker bones, and suffer as a big pharma cash cow. I learned this for personal experience.
Fantastic diagnostic. I do not know anyone in this area that can to this type of thorough diagnostic AND be able to repair the vehicle - take off the head. Thumbs up video.
I had a 'Frozen Shoulder (Adhesive capsulitis) last year, my primary care doctor referred me to an Orthopedic doctor . The Orthopedic doctor recommended PT instead of a cortisone injection. Did 8 months of PT and my frozen shoulder went away. Good luck with your PT and get well soon. Great video and explaining how to diagnose low compression.
After 10 years I went yo my GP Cortisone injection cleared mine it came back but nothing like as bad after a couple of years but another cortisone injection did the trick -- now 12+ years free of that horrible ache.
Pretty dang cool. Here I am thousands of miles away on a business trip overseas and still get to watch Eric O videos at 3 am. Total cure for jet lag and time changes! Thanks Eric. Very much appreciate all you put into making these great videos. I am a decent car, boat, and landsacape mechanic, (no where near your experience), but watch every video just for the sheer enjoyment. Still learn something every session. You should be teaching full time someplace probably like NASA. As one NY'er to another, awesome.... Mike B
Great info! The best part of your videos are your explanation of scan tool values and how they relate to engine mechanics... 3:18 explains current clamp and measuring starter current in relationship to weak compression (3:50)
The electrical engineer in me was glad you mentioned "conventional current." Yes, current (the electrons) flows from negative to positive. A lot of people don't know that. The convention of current flowing from positive to negative is basically to eliminate tons of negative numbers in the math. Another great diagnostic video, by the way.
Also an EE. "Current" is never the correct name for "flow of electrons". Current is defined as the rate of flow of _charge_ . Since electrons carry negative charge, when electrons flow from negative terminal to positive, they move negative charge (at some rate) from negative to positive terminal. This means that the _current_ in the direction from negative to positive terminal _is negative_ . Negative current in one direction is the same as positive current in the other. So this requires positive current (rate of charge flow) to be in the direction from positive terminal to negative. These are all part of the same convention, not alternatives. You can discuss electron flow and current and they are completely compatible. But when the word "current" is used as the name for electron flow itself, that is just incorrect.
Fair enough. For some reason, lately I've been hearing a number of youtubers and others blurring this electron flow vs current distinction, and making subsequent incorrect logical leaps (not Eric), either about basic electricity, or made up explanations about how "conventional current" is some sort of band aid to make things more convenient in the light of Franklin's "mistake". All of which serve to confuse people whose knowledge is not solid in this area. Most egregiously www.allaboutcircuits.com/textbook/direct-current/chpt-1/conventional-versus-electron-flow/. You can pretty much guarantee that where "conventional current flow" is mentioned, the explanation will be wrong.
Eric you are truly the best in explaining and sharing your knowledge. You explain things so that we can learn right along with you. Thanks for sharing your knowledge
Nice video. Takes me back to review a course I had in May, 2017, "Theory and Application of Pressure Transducers." Reviewing the course materials the case studies only covered mechanical issues never a burned exhaust valve being identified. Interestingly, to make a diagnosis for compression leakage, peak in cylinder pressure had to be correlated with top dead center. Leakage will be present where peak compression does not align with TDC (setting up another channel on ignition and adjusting the degrees BTDC to calculate actual TDC).
Eric, thank you for this great info. I look forward to the repair process. I've been up against arthritis as long as I can remember, tried the anti-inflammatory drugs once, but the side effects were worse than the arthritis. We just have to keep moving and use a mind over matter kind of attitude. Again thank you.
Excellent video!! You go way beyond the average guessing mechanic and use technical procedures to pinpoint the problem. Must say, really like the tool collection you have too. Thanks for sharing this and keep ahead of that arthritis.
John Thornton is an amazing instructor. Have been going to his classes for a number of years. He hits it out of the park every time. Yeah, Honda's are great vehicles, but not perfect. You did a great job explaining everything. Nice work my friend.
I love your case studies. I didn't really know what you were talking about most of the time lol, but the way you explained it helped me imagine it and did make some sense to me.
Thanks again for a full informative video and no worries on the rushed feelings. I got more out of you rushing and teaching than I get out of most people on their best days !!!
That Dave Decourcey video is a good one. I watched it a long time ago. Seemed like a really cool guy and he really knew his way around a scope. He passed away late last year.
Dave is correct. "Conventional current" was imagined by Franklin. His idea of current flowing from "+" to "-" is the reason that the arrows on schematic diagrams for things like diodes, transistors, and similar devices point in the direction they do, which is the opposite of electron current.
He makes a great point about disabling the fuel system for a compression test, and having the throttle open. Adding fuel, or anything other than air to a cylinder during the test can lead to very unreliable readings. In actual fact, for inexperienced fellas, or diy boys it makes more sense to use the amperage method, it is every bit as good a test. I have had plenty of engines with good compression readings still have internal mechanical problems.
I had a 3.8L Ford Windstar leaking between #2 and #3 cylinder once, had a blown head gasket. Thanks for sharing! Man you've got some nice tools. It will be interesting to see what you find when you tear it down.
pressure transducer brings new level of detail to a compression test . Could get same conclusion most times with old school or HF test tools but what you learn from seeing all this transducer info will pay off with the tricky fault diagnosis . Good informative vid. picoscope is superb bit of kit and having it run on windows a bonus in many ways, wish more scan tools would be built to load on notebooks and tablets over dedicated devices .
Great Video Diagnostics using the Pico Scope with the cylinder pressure sensor! If you had valve opening/closing specs, in degrees, that would be helpful to identify it all on the scope waveforms. WHEN YOUR GOOD, YOUR GOOD ! ! !
Excellent video Eric O. It's so hard to know when to just call it and know you're gonna be taking the head off. I understand that knowing is knowing, and I always would like to REALLY know for sure (that's probably why most of us got into the biz anyway) but, when you've got three other cars to get to and a ringing phone... This is the kind of situation where you really get to understand that time IS money. Thanks for all the great work.
I had a V6 Accord just like this, and it was one of the fastest rides I have ever driven! I ran it to 276.000 miles and sold it. I'm going to find a Copart wreck like it and go again.
HI Eric if you look closely at the exhaust pocket zoomed in you will see a definite point where it starts to ramp up when exhaust vale opens on good cylinder compared to the bad cylinder where it is more gradual
Thank you for posting a link to the files you saved during your testing. It was great to be able to look at them at our own pace and zoom into different areas that may not have been highlighted during the video. Please keep posting links to test data in future videos.
Do the Physio exactly as they tell you to. I've got Psoriatic Arthritis and Anti inflammatory drugs like Naproxen help but Physio helps more. Because of the arthritis I tend to not wanna move, but moving is exactly what needs to be done to help. Arthritis sucks but it's not too bad if you catch it early enough. I put off going to the doc for too long and ruined a lot of joints. I'll never be able to do gymnastics again.... of course I never did before...lol Take care and thanks for the video.
As mentioned to me years ago - your tools can make you or break you , the smoke machine test - showed smoke coming out the exhaust pipe and knowing the timing indicators aligned properly - pulling the head is the call 🤔👍✌️
I wish we had more people like you, that are dedicated to doing it right. I know many in my area that we call parts changers and bill you for it with out fixing the problem. I am disabled now and can no longer do my own work and things are above my skill level now. I love to watch your work and you are hard one to follow, you have great skill. Thank you for your time.
Gotta give credit where credit is due gotta say I'm up in the Cleveland area oh. I know about 15 mechanics shop owners and I only trust 2 to do work right including me I take pride in my worki dont cut corners like many others do I have to say you are a fantastic mechanic all around I know there is better diagnostic techs (Keith new age auto) but I can't find a mechanic that is a triple threat from repair to diagnostic to fab and just doing it right you diffently win the award for mechanic of the year
Good luck with PT, never did me any good post back surgeries... I did get a Health Mater Forever TENS unit on Amazon and that helped. If you look around the Amazon you can find the sticky pads cheap and in bulk. I did have to swap out the jacks to use the cheaper pads but it was well worth it, I shortened the cables and hardened everything with heat shrink. Now I just toss it in my pants pocket and run it all day.
Loved Sheba (dog) sniffing the car at the end of the video. Low compression is definitely not due to contraband. "Detected something under the seat. There's your problem, lady!"
Another great vid Eric. It would have been cool to see a secondary from both banks on that relative comp waveform. It could have possibly shown cam timing confirmed.
Boy, how lucky. Cyl 5 at TDC on compression stroke without hunting for it. Hopefully you have gotten yourself a tens unit by now, one of the best purchases I've ever made.
Since the customer knew it was the #5 cyl, Someone already did some testing before it got to Eric. If you want the proof of concept, go to Eric. He Da Man. Lucky it wasn't on the other bank. Nice to wake up to South Main Auto And a strong cup of coffee.
You are an intensely intelligent human being sir... I literally know zilch about automotive work but am mechanically inclined, since watching your videos I have been inspired to replace the leaky valve cover gasket on my car as well as the VVT solenoid for the intake side. Learned an incredible amount from you, thank you so much for such great videos Eric O!
I watched this whole video and honestly it’s really helping me get ideas for issues my Accord v6 is having. I’m also needing to do my timing belt but never even knew how to easily check it until just now when he showed how to check it
great video Eric O you can use the WPS500 in other ways and import them into the in cylinder waveform to see the realationship ex intake vacuum running and cranking look for anomilies in the vacuum pulls tailpipe with the j shaped stiff pico hose exhaust valve problems stick out dipstick for piston ring issues take care
😎 one other old school test before the leak down, is tipping just a bit of oil is the cylinder and if the compression rates.. rings.. if it does do anything valves.. then u know where to focus
Awesome video Eric and Thornton is the man on that stuff. That is a neat feature never paid attention that you could turn off the injectors on them. Glad to see the Pico out And nice that you have the pressure transducer. I'm still saving for mine lol. Great Job and thanks for all your hard work
Hope your shoulder gets better with therapy and doesn't require surgery. Interesting case study and I didn't see anything that jumped out so it's not that bad yet maybe valve seat/face carboned up & valve not seating fully. Still has good negative pressure, exhaust back pressure, valve timing, etc all look good but peak compression slightly lower & obviously leaking by leakdown & smoke check. Love ones like this that you turn into a learning experience. Wonder if valve adjustment was the root cause not allowing valve to cool on seat? Heading to NY my Uncle & Aunt passed away 2 days apart so I'll be there Saturday. If I get a chance I'll try and come see you but we'll see how it goes.
First of all Erick O. Loved the video made by Scanner Danner - you, Ivan and Paul to the "get together." Was great. All of we subscribers joined in on the fun. Loved the control arm presentation - laughed out loud. You, Ivan, Paul are "Da Man!" Thanks. You guys don't really know how much knowledge you are "giving away for free." :) Many "tanks."
Oh yeah compression checks are just like changing oil right? Lol couldn’t even begin to imagine… I have a crazy issue with my 05 Honda Accord. But mine has sat for 2 years with a full tank of low grade gas. I’m hoping that’s the only problem I have aside from needing to do maintenance. Love these videos
I have had a really bad back for years and just watching you work while leaning over the engine bay makes my back hurt more, would of loved to been a mechanic but glad I did not make that choice as I would of had to retire at 30.
I like the fact that you shared those Pico files. Great stuff to play around with. That's all I can do I realized after I saw that price. hehe Cool beans, great vid!
I just downloaded the software and the files. It is so cool to see what you are seeing on my own computer! I want a Picoscope but they are too expensive for me (DIY). This is the next best thing! Keep doing videos like this. I always learn something new.
Indeed, it's a great thing, it feels like I'm there in the shop with you looking through the data and stuff. That Pico thingie is an amazing tool to have. Great stuff, can't wait to see more data files in the future. :D
The tell tale here was in the shape of the expansion pocket. Look at 21:45 where you're flipping back and forth between #1 and #5. Note the differences in shape of the pockets and the beginning of the exhaust ramps. Cylinder #1 has more of a 'V' shaped pocket whereas #5 has a smooth 'U' shape. Once the exhaust valve opens the pressure should rise rapidly because there is a large pressure difference between the pressurized exhaust and the vacuum of the sealed cylinder. This creates more of a sharp straight diagonal line for the upwards curve of the expansion pocket. Likewise, if a cylinder isn't sealing that well then there's less of an immediate pressure difference right when the exhaust valve opens. This is because the entire time that the exhaust valve was supposed to be closed the cylinder was already filling with pressure from wherever the leak was. This creates a more gradual increase in pressure resulting in a smoother 'U' shape. A smooth 'U' pocket doesn't have to come from a leaking exhaust valve. It can come from any source of leakage. But it does indicate that leakage is present. Probably the best article I read on pressure waveforms is Anatomy of the Compression Waveform by Bernie Thompson at ATS. www.automotivetestsolutions.com/pressure-transducer-articles.html A lot of articles go over the names of the different parts of the waveform and what to look for etc. This one forces you to think about what's actually happening in the engine and why the pressures are the way they are. It's a very detailed walkthrough of the 4 cycle engine and how each step affects pressure in the cylinder.
Lol is that a pic of Scotty Kilmer on the dry erase board holding a chainsaw? Love the videos by the way. Keep on educating us. Every little bit helps. Thanks
Hey Eric! You said that you have enough evidence to "not suspect tight exhaust valves on Bank 2"... what exactly is that evidence? Did you check the clearances before you pulled the head off to ship it to the machine shop? I just had an 06 Accord V6 in the shop with 205k miles and similar symptoms, except the leak-down check showed perfect sealing on the BAD cylinder! All it needed was a valve adjustment for the tight exhaust valves :)
Considering that engines idle much smoother, and start easier after a really long highway drive, if an around town driven engine is a bit rough personally I wouldn't worry. We used to see it in brand new motorcycles all the time. Babied whilst new they would have hesitation and misfire issues until given a work out. Mates brother a good car mechanic said the same was true with cars.
The test and methods you show amaze me !!!. Awsome diagnostic without even touching a bolt. Thanks for making all this info available. I dont repair cars, I wont repair cars, but nothing like seeing a nice vid on YT and learn something new. Man, hurry up on hiring a guy for your shop to help with the "heavy lifting" for a while till your shoulder heal. Once you find a GOOD doctor, get advice and follow the directions as much as you can. Sucks not be at %100, but the only way to recover %100 is making the Doctors homework.
I will admit, i am no mechanic but I have watched three videos on dead valves but I you can hear it miss on the crank and that mixed with low compression, It has given me a clear red flag if I am looking at used cars, Thank you for making such detailed videos, Granted watching a mechanic talk dirty to an engine isn't what I would call a fun time, but in some weird way, its very relaxing
I had an issue with a 07 Pathfinder 4.0. The scanner shows misfire across all cylinders on passenger side and blown cat on passenger side. I found vehicle battery at 12.39 volts and I knew that it needed a new battery. As soon as I replaced it, it ran fine until the engine warmed up then it was hard to drive. The Pathfinder would nit go over 20 MPH. After replacing the cat it ran good.
Really enjoy your videos and even at almost 70 years old I learn a lot from them. I am on a fixed budget but have saved about 300.00 dollars for diagnostic equipment . My only piece of gear now is a Bosch code checker which works well. What would you suggest as the thing that would give me the most bang for my buck in my budget?
The cranking waveforms show much more difference between cyl 1 and 5 than the running ones, probably because at low cranking speed there is more time for air to leak out of the cylinder during the compression and expansion strokes. The cranking test also has atmospheric pressure at the start of the compression (due to WOT rather than idle manifold vacuum) so the cylinder pressures will be higher, increasing the amount of leakage. On the cyl5 cranking trace the pressure at the bottom of the expansion stroke is lower than at the bottom of the intake stroke, if the pressure is lower and the volume of the cylinder is the same (piston at BDC in both cases) then physics says there must be less air in the cylinder by the end of the expansion stroke - as there is no combustion you would expect the compression and expansion strokes to cancel out (you take a fixed amount of air at BDC intake, compress it to TDC firing, then expand it again to BDC expansion and end up back where you started....assuming a slightly idealised case where the intake valve closes exactly at BDC and the exhaust valve also opens exactly at BDC). I don't think the pressure trace can tell you where the leak is (inlet valve, ex valve, rings) - just that there is/isn't a leak....
Thanks for sharing the scope data, really interesting to have a look at
A comment of value. Thank you.
so, where is the good old leakdown tester :)
Intake runner pressure pulses can cross feed the cylinders.
You can tell exactly were a leak is with in cylinder wave forms. Id suggest you look into some of Bernie Thompson's training material.
WoW. Thanks man
Working on cars is time consuming enough, now making videos and bringing this kind of info and then some...Beyond Repair 🤙🏼
It depends on environment that you're in and you're in a if you're in a dealership you have more customers well in the waiting area and I'm waiting for their cars you don't have time to make videotapes you can only do this in private shops where you have one two cars a day
As a first year apprentice technician I love watching your case studies and learning more about the electronic diagnostics instead of just cranking wrenches! Keep up the extremely hard work, we are still extremely grateful 🙏
Wow ! i have been an Electronic tech for over 50 Years and I am so impressed at your skills
to understand how these modern cars use electronics to do everything ! The days of the shade tree
mechanic are forever gone. If you're successfully fixing modern cars, you understand the electronic
components involved ! Kudos to you, and to the handful of techs out there with your knowledge !
I know that you will do well and your videos are teaching many would be techs about what's needed
to diagnose these newer vehicles. Love watching your videos and what it takes to resolve problems
that did not exist 25 years ago.. Amazing. Thanks ! Keep up the great work..
Not afraid to admit what you know and don't. Respect you more every time I see one of your videos.
HiEric
I won;t say you missed your calling as you are definetly atop grade mechanic.
However you may not have noticed yuar also grade a Instructor. People just seem to understand sometimes difficult concepts easily from your videos.
Please keep them coming and say hi to Sheba for me as well.
He's famous and has a huge following and a solid platform, so he made the right decision. I can't name a single Grade A car repair instructor. Can you?
Paying for school to be a tech but I'm learning so much from SMA idk sometimes why I'm going to school 😂😂
My arthritis began around 43 in my lower back , It's now pretty much everywhere to a degree . We humans are far more fragile than I had ever thought when I was younger . TheReaper!
joeblackakareaper Same here. L5 & L4 are deteriorating daily. Still bent over a hood though...By the time the damage reveals itself you’re trapped.
Severe Author comes from eating animal proteins for a life time. You're simply consuming the wrong type of fuel!
Rj Aquaponics - That’s a load of nonsense. We’re literally made of animal protein - the most compatible, extremely bioavailable protein for human consumption is animal protein. We need animal protein and fats for proper function of our endocrine system among other systems in the body.
The only reason people live, “well,” as vegans is because the body is incredibly resilient and can still survive on almost anything you can feed it.
I’d venture to say the OP could eat an elimination diet of solely red meat for a month or two and see improvement in his condition.
I’m speaking from personal experience.
@@JosephQPublic Because we are made of proteins, our bodies have a hard time digesting animal protein. It is a constant battle of eliminating the acid loads while fighting autoimmune issues. It is not our proteins that digest the animal proteins, it is our microbiome that makes the animal flesh and fats available. The cholesterol in meats are not the cholesterol used by our brains, we manufacture that type of cholesterol. Bar none, everyone who eats a meat, cheese, milk and eggs diet will eventually grow slower, sicker, weaker bones, and suffer as a big pharma cash cow. I learned this for personal experience.
Nice simple explanation of how relative compression works on a scope for us dummies. Thanks from the UK.
thank you...i'm a 'Bucket full of Harbour freight' man...and I learnt a lot.
Stepping back in time. Interesting to see how the technical diagnostic tools and process has changed from then to today September 2020
Fantastic diagnostic. I do not know anyone in this area that can to this type of thorough diagnostic AND be able to repair the vehicle - take off the head. Thumbs up video.
I had a 'Frozen Shoulder (Adhesive capsulitis) last year, my primary care doctor referred me to an Orthopedic doctor . The Orthopedic doctor recommended PT instead of a cortisone injection. Did 8 months of PT and my frozen shoulder went away. Good luck with your PT and get well soon. Great video and explaining how to diagnose low compression.
After 10 years I went yo my GP Cortisone injection cleared mine it came back but nothing like as bad after a couple of years but another cortisone injection did the trick -- now 12+ years free of that horrible ache.
Bet your butt we want to see the whole fixing process on this Honduuu!
This was a great case study! Thanks for showing it to us.
Pretty dang cool. Here I am thousands of miles away on a business trip overseas and still get to watch Eric O videos at 3 am.
Total cure for jet lag and time changes! Thanks Eric. Very much appreciate all you put into making these great videos. I am a decent car, boat, and landsacape mechanic, (no where near your experience), but watch every video just for the sheer enjoyment. Still learn something every session. You should be teaching full time someplace probably like NASA.
As one NY'er to another, awesome....
Mike B
Great info! The best part of your videos are your explanation of scan tool values and how they relate to engine mechanics...
3:18 explains current clamp and measuring starter current in relationship to weak compression (3:50)
Yes, we want to see the repair video Eric. We cant let you go through the pain alone!
The electrical engineer in me was glad you mentioned "conventional current." Yes, current (the electrons) flows from negative to positive. A lot of people don't know that. The convention of current flowing from positive to negative is basically to eliminate tons of negative numbers in the math. Another great diagnostic video, by the way.
Also an EE. "Current" is never the correct name for "flow of electrons". Current is defined as the rate of flow of _charge_ . Since electrons carry negative charge, when electrons flow from negative terminal to positive, they move negative charge (at some rate) from negative to positive terminal. This means that the _current_ in the direction from negative to positive terminal _is negative_ . Negative current in one direction is the same as positive current in the other. So this requires positive current (rate of charge flow) to be in the direction from positive terminal to negative.
These are all part of the same convention, not alternatives. You can discuss electron flow and current and they are completely compatible. But when the word "current" is used as the name for electron flow itself, that is just incorrect.
I hear what you're saying. I was being a bit vague. I was just making note that Eric O. had the direction of electron flow correct.
Fair enough. For some reason, lately I've been hearing a number of youtubers and others blurring this electron flow vs current distinction, and making subsequent incorrect logical leaps (not Eric), either about basic electricity, or made up explanations about how "conventional current" is some sort of band aid to make things more convenient in the light of Franklin's "mistake". All of which serve to confuse people whose knowledge is not solid in this area. Most egregiously www.allaboutcircuits.com/textbook/direct-current/chpt-1/conventional-versus-electron-flow/. You can pretty much guarantee that where "conventional current flow" is mentioned, the explanation will be wrong.
Lol my head hurts now, all I know is I hook up wires and bulbs light up haha
+Graham Wideman what?
Eric you are truly the best in explaining and sharing your knowledge. You explain things so that we can learn right along with you. Thanks for sharing your knowledge
Cant get enough of your videos dude, you work on vehicles I'll never come across - I watch em anyway
Nice video. Takes me back to review a course I had in May, 2017, "Theory and Application of Pressure Transducers." Reviewing the course materials the case studies only covered mechanical issues never a burned exhaust valve being identified. Interestingly, to make a diagnosis for compression leakage, peak in cylinder pressure had to be correlated with top dead center. Leakage will be present where peak compression does not align with TDC (setting up another channel on ignition and adjusting the degrees BTDC to calculate actual TDC).
Eric, thank you for this great info. I look forward to the repair process. I've been up against arthritis as long as I can remember, tried the anti-inflammatory drugs once, but the side effects were worse than the arthritis. We just have to keep moving and use a mind over matter kind of attitude. Again thank you.
Eric you did a great job of explaining them waveforms. Until the next one.
Excellent video!! You go way beyond the average guessing mechanic and use technical procedures to pinpoint the problem. Must say, really like the tool collection you have too. Thanks for sharing this and keep ahead of that arthritis.
John Thornton is an amazing instructor. Have been going to his classes for a number of years. He hits it out of the park every time. Yeah, Honda's are great vehicles, but not perfect. You did a great job explaining everything. Nice work my friend.
3:05 Love that Scotty Kilmer with a chainsaw on the wall XD
I love your case studies. I didn't really know what you were talking about most of the time lol, but the way you explained it helped me imagine it and did make some sense to me.
Thanks again for a full informative video and no worries on the rushed feelings. I got more out of you rushing and teaching than I get out of most people on their best days !!!
Absolutely fantastic information. Lots going on in the world of diagnostics and the added links are a huge help, thanks. I really enjoyed this one.
That Dave Decourcey video is a good one. I watched it a long time ago. Seemed like a really cool guy and he really knew his way around a scope. He passed away late last year.
Dave is correct. "Conventional current" was imagined by Franklin. His idea of current flowing from "+" to "-" is the reason that the arrows on schematic diagrams for things like diodes, transistors, and similar devices point in the direction they do, which is the opposite of electron current.
He makes a great point about disabling the fuel system for a compression test, and having the throttle open. Adding fuel, or anything other than air to a cylinder during the test can lead to very unreliable readings. In actual fact, for inexperienced fellas, or diy boys it makes more sense to use the amperage method, it is every bit as good a test. I have had plenty of engines with good compression readings still have internal mechanical problems.
I had a 3.8L Ford Windstar leaking between #2 and #3 cylinder once, had a blown head gasket.
Thanks for sharing! Man you've got some nice tools.
It will be interesting to see what you find when you tear it down.
Wow, 4:40 am. Turn on computer, bring up you tube and watch SMA!! Good vid.
pressure transducer brings new level of detail to a compression test .
Could get same conclusion most times with old school or HF test tools but what you learn from seeing all this transducer info will pay off with the tricky fault diagnosis .
Good informative vid. picoscope is superb bit of kit and having it run on windows a bonus in many ways, wish more scan tools would be built to load on notebooks and tablets over dedicated devices .
Great Video Diagnostics using the Pico Scope with the cylinder pressure sensor! If you had valve opening/closing specs, in degrees, that would be helpful to identify it all on the scope waveforms.
WHEN YOUR GOOD, YOUR GOOD ! ! !
Appreciate the vid and all the time you took to give us those files, definitely gonna give it a look. Cheers Eric
Excellent video Eric O. It's so hard to know when to just call it and know you're gonna be taking the head off. I understand that knowing is knowing, and I always would like to REALLY know for sure (that's probably why most of us got into the biz anyway) but, when you've got three other cars to get to and a ringing phone... This is the kind of situation where you really get to understand that time IS money. Thanks for all the great work.
I had a V6 Accord just like this, and it was one of the fastest rides I have ever driven! I ran it to 276.000 miles and sold it. I'm going to find a Copart wreck like it and go again.
You were specially good at explaining things in this video. I learned how to use my oscilloscope for compression test. Not bad
HI Eric if you look closely at the exhaust pocket zoomed in you will see a definite point where it starts to ramp up when exhaust vale opens on good cylinder compared to the bad cylinder where it is more gradual
As always thank you for the time you spend making these videos.
Thank you for posting a link to the files you saved during your testing. It was great to be able to look at them at our own pace and zoom into different areas that may not have been highlighted during the video. Please keep posting links to test data in future videos.
Do the Physio exactly as they tell you to. I've got Psoriatic Arthritis and Anti inflammatory drugs like Naproxen help but Physio helps more. Because of the arthritis I tend to not wanna move, but moving is exactly what needs to be done to help.
Arthritis sucks but it's not too bad if you catch it early enough. I put off going to the doc for too long and ruined a lot of joints. I'll never be able to do gymnastics again.... of course I never did before...lol
Take care and thanks for the video.
Nice too see all the info you can get just by looking to those compression "waveform"! I'm impress! nice job
I keep saying it and I'll say it again...ERIC IS A GENIUS...and he can predict the future :: )
As mentioned to me years ago - your tools can make you or break you , the smoke machine test - showed smoke coming out the exhaust pipe and knowing the timing indicators aligned properly - pulling the head is the call 🤔👍✌️
I wish we had more people like you, that are dedicated to doing it right. I know many in my area that we call parts changers and bill you for it with out fixing the problem. I am disabled now and can no longer do my own work and things are above my skill level now. I love to watch your work and you are hard one to follow, you have great skill. Thank you for your time.
Great diagnostics, thank you Eric!!!
3:50 +1 for the "If it ain't red, leave it in the shed" poster on the wall.
you blew up my brain i bought the earthquake gun but i'm not buying diagnostic machine as long as i'm watching your channel thank you for posting
Gotta give credit where credit is due gotta say I'm up in the Cleveland area oh. I know about 15 mechanics shop owners and I only trust 2 to do work right including me I take pride in my worki dont cut corners like many others do I have to say you are a fantastic mechanic all around I know there is better diagnostic techs (Keith new age auto) but I can't find a mechanic that is a triple threat from repair to diagnostic to fab and just doing it right you diffently win the award for mechanic of the year
youngguncar care hell yes
I'll second that ! TheReaper!
Thank You For Your Time .
Wow; a masterful diagnosis!
Good luck with PT, never did me any good post back surgeries... I did get a Health Mater Forever TENS unit on Amazon and that helped. If you look around the Amazon you can find the sticky pads cheap and in bulk. I did have to swap out the jacks to use the cheaper pads but it was well worth it, I shortened the cables and hardened everything with heat shrink. Now I just toss it in my pants pocket and run it all day.
Loved Sheba (dog) sniffing the car at the end of the video. Low compression is definitely not due to contraband. "Detected something under the seat. There's your problem, lady!"
Another great vid Eric. It would have been cool to see a secondary from both banks on that relative comp waveform.
It could have possibly shown cam timing confirmed.
Take care of that shoulder! I got bad diagnosis years ago, now there isnt much left to fix. PT is better than the alternative.
Boy, how lucky. Cyl 5 at TDC on compression stroke without hunting for it. Hopefully you have gotten yourself a tens unit by now, one of the best purchases I've ever made.
Since the customer knew it was the #5 cyl, Someone already did some testing before it got to Eric. If you want the proof of concept, go to Eric. He Da Man. Lucky it wasn't on the other bank. Nice to wake up to South Main Auto And a strong cup of coffee.
You are an intensely intelligent human being sir... I literally know zilch about automotive work but am mechanically inclined, since watching your videos I have been inspired to replace the leaky valve cover gasket on my car as well as the VVT solenoid for the intake side. Learned an incredible amount from you, thank you so much for such great videos Eric O!
I watched this whole video and honestly it’s really helping me get ideas for issues my Accord v6 is having. I’m also needing to do my timing belt but never even knew how to easily check it until just now when he showed how to check it
great video Eric O you can use the WPS500 in other ways and import them into the in cylinder waveform to see the realationship ex intake vacuum running and cranking look for anomilies in the vacuum pulls tailpipe with the j shaped stiff pico hose exhaust valve problems stick out dipstick for piston ring issues take care
Yeah I still have a lot of discovery with it :D
Nice! Its been a while since you made a mini series! Cant wait to see it!
😎 one other old school test before the leak down, is tipping just a bit of oil is the cylinder and if the compression rates.. rings.. if it does do anything valves.. then u know where to focus
Awesome video Eric and Thornton is the man on that stuff. That is a neat feature never paid attention that you could turn off the injectors on them. Glad to see the Pico out And nice that you have the pressure transducer. I'm still saving for mine lol. Great Job and thanks for all your hard work
Hope your shoulder gets better with therapy and doesn't require surgery. Interesting case study and I didn't see anything that jumped out so it's not that bad yet maybe valve seat/face carboned up & valve not seating fully. Still has good negative pressure, exhaust back pressure, valve timing, etc all look good but peak compression slightly lower & obviously leaking by leakdown & smoke check. Love ones like this that you turn into a learning experience. Wonder if valve adjustment was the root cause not allowing valve to cool on seat? Heading to NY my Uncle & Aunt passed away 2 days apart so I'll be there Saturday. If I get a chance I'll try and come see you but we'll see how it goes.
Great diagnostic video! Would love to see repair done in a video.
man the beard! ain't ya had that since 12? great video as usual Eric, keep em coming
I love how you do advanced diagnosis and really know how to read your graphs :) love watching you little fellow :D
Thanks for sharing the files, didn't know you could view them for free.
First of all Erick O. Loved the video made by Scanner Danner - you, Ivan and Paul to the "get together." Was great. All of we subscribers joined in on the fun. Loved the control arm presentation - laughed out loud. You, Ivan, Paul are "Da Man!" Thanks. You guys don't really know how much knowledge you are "giving away for free." :) Many "tanks."
Thank you . Really love the information and the links. Please keep these type of videos coming!
Will be looking for part 2
wow i never knew, connecting a car to a computer, could Give you some Idea and ALOT of Info on what it could be!
I'LL BE LOOKIN FOR PART 2 OF THIS ONE. HAPPY FALL AT 4:04 PM YOUR TIME FRIDAY SEP 22.
Another awesome diagnostic vid Eric! Can't wait to see part 2.
Oh yeah compression checks are just like changing oil right? Lol couldn’t even begin to imagine… I have a crazy issue with my 05 Honda Accord. But mine has sat for 2 years with a full tank of low grade gas. I’m hoping that’s the only problem I have aside from needing to do maintenance. Love these videos
Look at you knowing all this stuff about circuits. Almost like you're a rocket surgeon...
I have had a really bad back for years and just watching you work while leaning over the engine bay makes my back hurt more, would of loved to been a mechanic but glad I did not make that choice as I would of had to retire at 30.
Some excellent diagnostic tests. Thanks
that smoke tester really puts out! makes the one at my shop look like a joke, i might have to get one of those!
I like the fact that you shared those Pico files. Great stuff to play around with. That's all I can do I realized after I saw that price. hehe
Cool beans, great vid!
I plan on doing that every time I have a video using it. I mean the software is free and no reason why you guys can't have a peek at it too right?
I just downloaded the software and the files. It is so cool to see what you are seeing on my own computer! I want a Picoscope but they are too expensive for me (DIY). This is the next best thing! Keep doing videos like this. I always learn something new.
Indeed, it's a great thing, it feels like I'm there in the shop with you looking through the data and stuff. That Pico thingie is an amazing tool to have. Great stuff, can't wait to see more data files in the future. :D
The tell tale here was in the shape of the expansion pocket. Look at 21:45 where you're flipping back and forth between #1 and #5. Note the differences in shape of the pockets and the beginning of the exhaust ramps. Cylinder #1 has more of a 'V' shaped pocket whereas #5 has a smooth 'U' shape.
Once the exhaust valve opens the pressure should rise rapidly because there is a large pressure difference between the pressurized exhaust and the vacuum of the sealed cylinder. This creates more of a sharp straight diagonal line for the upwards curve of the expansion pocket.
Likewise, if a cylinder isn't sealing that well then there's less of an immediate pressure difference right when the exhaust valve opens. This is because the entire time that the exhaust valve was supposed to be closed the cylinder was already filling with pressure from wherever the leak was. This creates a more gradual increase in pressure resulting in a smoother 'U' shape.
A smooth 'U' pocket doesn't have to come from a leaking exhaust valve. It can come from any source of leakage. But it does indicate that leakage is present.
Probably the best article I read on pressure waveforms is Anatomy of the Compression Waveform by Bernie Thompson at ATS.
www.automotivetestsolutions.com/pressure-transducer-articles.html
A lot of articles go over the names of the different parts of the waveform and what to look for etc. This one forces you to think about what's actually happening in the engine and why the pressures are the way they are. It's a very detailed walkthrough of the 4 cycle engine and how each step affects pressure in the cylinder.
Lol is that a pic of Scotty Kilmer on the dry erase board holding a chainsaw? Love the videos by the way. Keep on educating us. Every little bit helps. Thanks
Great find, additional misfire code are most likey other exhaust valves..
Hey Eric! You said that you have enough evidence to "not suspect tight exhaust valves on Bank 2"... what exactly is that evidence? Did you check the clearances before you pulled the head off to ship it to the machine shop?
I just had an 06 Accord V6 in the shop with 205k miles and similar symptoms, except the leak-down check showed perfect sealing on the BAD cylinder! All it needed was a valve adjustment for the tight exhaust valves :)
At 3:01 the water jug on the wall is looking at you. lol
Considering that engines idle much smoother, and start easier after a really long highway drive, if an around town driven engine is a bit rough personally I wouldn't worry. We used to see it in brand new motorcycles all the time. Babied whilst new they would have hesitation and misfire issues until given a work out. Mates brother a good car mechanic said the same was true with cars.
The test and methods you show amaze me !!!. Awsome diagnostic without even touching a bolt. Thanks for making all this info available. I dont repair cars, I wont repair cars, but nothing like seeing a nice vid on YT and learn something new. Man, hurry up on hiring a guy for your shop to help with the "heavy lifting" for a while till your shoulder heal. Once you find a GOOD doctor, get advice and follow the directions as much as you can. Sucks not be at %100, but the only way to recover %100 is making the Doctors homework.
I will admit, i am no mechanic but I have watched three videos on dead valves but I you can hear it miss on the crank and that mixed with low compression, It has given me a clear red flag if I am looking at used cars, Thank you for making such detailed videos, Granted watching a mechanic talk dirty to an engine isn't what I would call a fun time, but in some weird way, its very relaxing
Jeez man you have a lotta kit and special tools I'm very impressed. Another great video, keep 'em comin..
No decent mechanic could do the right job without them and the ability to use them.
You could further stick your borescope down the spark plug holes to check the exhaust valves.
She shoulda gone for the ole banana in the tailpipe.
LOL doggie checking your work for quality control at 37:36.
Great vid again Eric,
Stay gold.
Pico software is cool and they keep on improving it... core of the Dutch translation by yours truly, BTW.
Hey, kudos for that contribution!
Coffee and South Main in the morning, nice.
Nice diagnostic video Eric. However, I believe to be your third Hondo video with rather low miles and needing major work.
Lol, @ 3:20, that yellow container funnel thingy looks like one of those Easter Island statues... 🤣🤷🏽♀️😂
I had an issue with a 07 Pathfinder 4.0. The scanner shows misfire across all cylinders on passenger side and blown cat on passenger side. I found vehicle battery at 12.39 volts and I knew that it needed a new battery. As soon as I replaced it, it ran fine until the engine warmed up then it was hard to drive. The Pathfinder would nit go over 20 MPH. After replacing the cat it ran good.
I have a screwed up shoulder from a. Fall years ago it took my job away , now arthritis in my lower back, ahh the life of a mechanic
Really enjoy your videos and even at almost 70 years old I learn a lot from them. I am on a fixed budget but have saved about 300.00 dollars for diagnostic equipment . My only piece of gear now is a Bosch code checker which works well. What would you suggest as the thing that would give me the most bang for my buck in my budget?