I understand your logic but that’s generally not the case in my experience. Probably because it’s German and they wanted to be different! Silly 13mm bolts and weird spark plug threads.
Normally forced induction engines have lower compression then naturally aspirated engines to compensate for the extra air that consequently increases the compression during acceleration, otherwise dependability would become an issue do to the engine running too hot in the combustion chambers
Great video. Might be worth mentioning that if you don't have a leak down tester, you can pur a squirt of oil in the offending cylinder and test again. If the compression comes up it is more likely going to be on the bottom end, if not it's more than likely the valves.
I dont like this method. Auto parts stores all over the place rent leak-down testers for free and I believe its more than worth the trouble to do the proper test. I have had several cases of extreme carbon buildup on the exhaust valves (I live in the city, stop and go traffic) where this method would cause a rise in compression and give a false diag of bad engine when it just needed a head job.
Samuel Michelson Did you watch the video or just comment? I believe I mentioned at the beginning and the end of the video that a leak down test would be best, but this can get you started. Also, if you watch the leak down video linked in the description I show how you can use a compression tester to perform a leak down test. Thanks for your input.
EricTheCarGuy, yeah, I watched the video. Did you read my comment thanking you for telling people about leak-down testing? I was referring to my dislike for people putting oil in the combustion chamber and seeing if it changes the compression readings. I dont think there is any useful information to be gained from doing this as per reasons already stated.
Samuel Michelson No I didn't. Sorry I missed that. I don't have an issue with putting oil in the cylinder. For me, if you find a big leak, you know it's coming apart anyway. Thanks again for your input.
You’re speaking my language now. Lost my hpfp, cam shaft sensor was the codes. Replaced both, and grgegrgrhrhrh. Take off the cover, timing chain exhaust sprocket sheared off, and the chain was broken. When it died driving, there was NO significant sound or noise at all, no shaking nothing just.. dead car. I’m hopeful, that the chain broke upon my attempt to restart. As there was never a fire.. just cranking for a second. Then noise then nothing. I am willing to replace the rods and head gasket etc. and your videos will be my Bible. I need to repair this car so bad. I gambled when my last one blew up, and was toast, hopeful for a decent long term ride. I did get 30k miles before it failed
Compression tests are useful to diagnose a myriad of cylinder problems, as low compression could be due to bent valves, worn valve seats, leaking head gasket or worn out piston rings. As you said, it is one step to get clear results of an engine failing, not necessarily bent valves.
VOTE FOR ERIC!! Eric, you should enter this video into the Cardone Tech Video Contest. I'm positive ALL (well let's not include the haters, lol) of your subscribers would vote for you!!!
Thank you. You said, "you can rent compression kits", I didn't know that and I need a kit to check my car. Good to learn something new, everyday. Yesterday was "leave Mary alone". :-D
Always a pleasure to watch and learn from your uploads Eric. No heavy metal, expert knowledge/teaching and a sense of humour make your channel my first stop. Thankyou, and greetings from Western Australia.
Good job Eric. If anyone needs to see the leak down test I saw it pop up in the i on the top right. This is accessible at any time during the video clicking or tapping on the I. Pause the video and it shows up.
pretty sure it's the "hose" more than anything, if you watch the hose when cranking closely, you'll see them really expand and contract...... (way too soft/flimsy) Also the check valve is up in the tester body by the gauge and not down at hose ends, which means the "volume" of the hose becomes part of the total cylinder and head volume. (wrong location for accurate readings) it's the same as having lower compression ratio due to having larger volume head chambers, lower piston deck height or head shims/thick gaskets. I don't know the total volume of the hose or adapters, which appears to be large overall, so I wouldn't doubt if it's skewed by well over 30PSI ;)
when you replace your spark plug with just tiny compression tester fitting (like in this video) the compression ratio decreases in your cylinder. Because the fitting is a lot shorter than a spark plug. Hence the low reading on the tester.
Thanks for the new video Eric. I as well did a compression test on my 96 gt and the results were stunning 180psi 1,2,4,5,6,7,8 but #3 had 135psi. Time to tear into it
i bought a cheap cavalier with similar compression results (i compression test cars before i buy them), but hey, it was cheap. It ran fine for several years before i scrapped it for other reasons.
Harbor Freight to the rescue! l know your not a fan of their stuff, but it's convenient and cheap! Above all l am surprised it had a fitting for the Mini! Useful info. Thank you. Looking forward to the engine tear down.
Not to mention....it lifetime warranty on hand tools and most others have a year or 2. And they replace with no hassle at all. I took 3 brake bleeders back 1 after another with no questions ask
Thanks for the video Eric! Eric has mentioned liking Pittsburgh Pro tools in previous videos. He switched to a different brand of engine stands during the Fairmont build.
@@panzerveps ok. Yeah I haven't kept up I knew he did something. Costly mistake. One time I put the crank pulley on backwards on a Honda and broke the teeth. My $350 car turned into $400 real quick.
Just one cylinder to plug into and all cylinders are tested at the same time eliminating a battery getting weaker skewing tests. Though a battery charger is a cheaper way to increase accuracy. Just use a multimeter and test the next cylinder when the voltage is the same.
to my experience variable camshaft and electronic throttle bodies can greatly influence a compression tests.. on some engines you must use a scan tool to activate a compression test function which will not only cut off fuel but will also fully open the throttle plate... just pressing the pedal will not fully open it in alle cases
I've gotta find a tool that enables this function! Hopefully it's compatible. I have an older scan tool, but I'm sure I've never seen this feature. I'll just have to get the -special Schwaben one- Foxwell NT510 for Minis (and BMWs, RRs).
Eric, this is somehow unrelated but the idea popped on another video: car electrical connectors. For some bloody reason, I haven't met a single mechanic who changes the connector housing when it's broken. Everyone makes a ghetto repair with tie-ups or electrical tape. Connector housings even for mercedes or audis are like $2-5 each and it's quicker to cut the old housing with pliers, check the pins are OK and fit a new connector. Click, brand new. Even on dealerships they never fix them properly. I struggled with my broken maf connector for years only to discover the housing was €3.61. Just an idea for discussion.
Hey eric, I love your videos! I have learned so much from you in the last couple of years. I do have a non automotive question though. What camera are you using? Its SO good!
Use a bore scope camera in the up position so you can see the valves rotate the engine with a breaker bar from the crankshaft pulley and look to see if you have bent valves when they open and close
Thanks Eric. Sorry to rub salt in the wound, but thanks again for showing me all the reasons why I can be happy I didn't buy a Mini when I was thinking about doing so.
I think i got lucky. I had a crack no start issue i was chasing down on my 98 4v cobra motor which i thought was because of an electrical problem i had from a weird being burned on the egr. Long story short, while chasing down this issue, i did a compression test and everything was 125-130psi (18cc dished pistons) across the board. I found later the secondary chain was broken. I literally just found the issue so i haven't it'll the head/motor but i think I may have dodged a bullet. The primary Caine are new and have less than 100 miles on the powertrain but the heads were untouched. Lesson learned, change everything.
It definitely has a Schrader valve. The gauge doesn't return to zero on any stroke other than compression. That means pressure is retained in the hose and gauge, hence a valve.
Thanks for this! Mine has a W11, but still gives me peace of mind to hear your interpretation of the results. I had low to mid hundreds the last time I did a test, but I think it may not have been warm enough and I'm sure that gauge hose wasn't tight enough. I'll do another one, along with the wet test, soon enough.
Yeah, that seemed to be a huge issue when I was -trying to run- running the test. I figure I'll just take the intake hose off to make sure it's opening, or have it held open if it isn't.
Thank you SO MUCH for explaining that bit about Leak-Down testing! I was just assessing a junkyard engine for head gasket issues the other day and pulled out the differential pressure guages, really gives you a good idea of the internal health of an engine without tearing it down!
My 08 Subaru stalled a week ago on my way to work. Her timing belt snapped unfortunately and I’m worried that her valves may have gotten bent too which is an expensive fix. I won’t know until a bit after Tuesday.
Ive got engine management light on my mk4 golf that doesnt want to go away. Had new spark plugs, temp sensor, crank sensor. Diagnosis keeps saying misfire on a cylinder and also temp sensor but they were all replaced just months ago. Car runs fine
He's mentioned in other videos and in his newsletter that he didn't torque the crank bolt properly, causing the engine to go out of time, bending the valves. This happened after the engine repairs. So he had to take the head off, replace the valves, and redo the timing job. It's all back together and running fine now.
Someone should also mention that if you havent even heard of Leak-Down Testing before: It is very simple to do, Only takes a little while longer than doing a compression check, Air compressor, differential pressure guage set and a wrench to turn your crankshaft are the only extra tools you will need from doing a compression check
My nieces car had a similar burnt valve. It didn't look bent on my valve grinder so I think something got between the valve and seat causing it to overheat the valve and melt it. The valve is now included on my wall of oddities with other interesting parts I've removed over the years.
hey Eric like your videos.after you checked the compression in two of the piston chambers do you not have to rotate the crank or cam shaft so that the inlet and exhaust valve seats are closed in the other two piston chambers before testing the other 2.also how much play should the valve stems have in the stem guides.any tips on checking if valves are perfectly straight or if there is too much play in the guides on a pitbike 👍
I have a 09 R56 JCW with the same problem. Took it to Mini and they said cylinder 3 has 0 compression. They told me I needed a new engine. Once I got the car back the paper work said it is possibly a bad piston ring. I am pretty sure I have bent valves too that don’t require a new $10k engine.
I think the low compression numbers you got are the result of the engine being turbocharged. When the turbo kicks in, and starts making boost, the cylinder pressures will jump dramatically. If you have hi cylinder pressure to begin with, the added boost would most likely, at the very least lift the head enough to blow the head gasket fire rings. Just a thought there. I thought about it a little more. It could also be the result of advanced exhaust valve timing also. That would cause low pressure to. I'm not saying cams out of time, but, again designed do to turbocharging.
The timing on this engine is fine. I just set it before doing the test. Many have suggested that Harbor Freight compression gauges often read low. I think that's the most likely cause. Thanks for your input.
@@ericthecarguy thanks Eric, your Wilkome. I have watched all the vids on the mini. Including the timing belt change. That's why I said it wasn't a mechanical misalignment. But a designed application of the exhaust timing. To reduce the initial cylinder pressures. I wasn't claiming at all that it was a mechanical timing issue, or bad alignment on your part. I hope this clears it up for you. If the calculated, or designed compression ratio is relatively high 9:1 or higher, you can advance the exhaust valve timing to reduce the initial cylinder pressure to avoid too high pressure once the turbo starts making boost.
thank you for your video, I've got a 2007 mini cooper hardtop and your car sounds almost exactly like mine after jumping time. where did you get your compression tester and what brand was it?
Nice video. I wanted to free up the pistons on my SUV that's been sitting on the driveway for the past 5 years due to some problem with distributor. So, I am going to take off spark plugs and pour two teaspoons of engine oil into each hole of spark plugs and turn the crankshaft manually in clockwise after a week of letting the oil sink. So is this the way to do it or will it mess up the timing . And , is there certain limit on number of turns or can I turn it few more times until I feel the pistons being lubricated? I subscribed . Thank you.
Hey Eric, I tried to put a new timing belt on my 2000 Chrysler Concorde LXI 3.2, in my driveway? The belt never broke? Just was doing preventative maintenance. 158,000 on the engine? I lined all the timing marks up, put it back together, no start? Eventually got frustrated, put it on a flatbed, to a mechanic, his diagnosis was bent valves on the drivers side? I bought the timing belt kit, with water pump, installed that, everything spun fine? Would you recommend fixing this car, or try and sell it as is? I put at least $3,500.00 into this car in the last year? From struts, to injectors? Tires, rims, sensors, Evap system, ect.. ect… What would you recommend I do? I had to buy a new car, but this Chrysler ran like a top, before I messed with the timing belt? Can you recommend what to do with this car?
Without doing wet compression we can't conclude either it's piston rings issue or valve leaking... If in wet compression, reading improved not improved that means from valve it's leaking.. If reading improved means rings have leak. If two cylinder HV low compression then gasket burnt..
THANK YOU Eric!! You confirm my suspicion. This is exactly my situation after I did a dry and wet compression test (0 on both tests in cylinder 2, on a 95 corolla 1.8 7afe that I bought for my father. But would it cause engine not able to rev more than 3k rpms?
I have a 2.3 l Ford , crank no start .0 compression on 4 cylinders . I pulled the cover and found the cams were out of time ,possible tooth jump. Is it possible on this interference motor that timing jump bent all or half the valves and still continues to crank? I know this is a crap motor . I will try a leak down.
Hey Eric I have 91 civic Si it won’t start and backfires out of the intake. I checked timing and it’s good. Suggestion on what to test next? It has fuel and spark
I have Subaru which is a interference engine and it had 0 comp on cyl 3 and 1 which are on the right side of the engine I checked the timing belt and it was off by 5 teeth. I realigned the belt and it now all cyl show 150. Is it possible to have bent valves and good compression? Do I need to do the leak down test?
I have exhaust valve that moves enough to open but does not fully close. I found by removing valve cover and pinpointing the noise. The valve doesn't close therefore the rocker arm is bouncing off the cam lobe. Is the valve necessarily bent or could something else be making it stick?
That's a factory turbo engine so there's less compression because there's forced induction. Otherwise engine would probably crap out after 60,000 miles. (Typically an issue people run into after installing eBay turbochargers on their cars without doing anything else to the engine block.)
Hi Eric, I have a car with noisy valves KIA Sportage :(, in your example why would three cylinders be OK and only one have bent valves. What would cause that? thanks
My timing chain broke when I tried to start my Toyota PU. As the valves were not moving when I cranked the engine to try and start her and my engine was a interference type there is a good chance the piston hit a valve. Would a leak down be worth the effort?
Quick question Eric. I have a ls2 GTO and when it gets to op temp it makes a faint tump sound but when the fan kicks on or if i rev it it'll go away? Any idea? P.s big fan love your vids!
hey eric i have a 2004 mdx that cranks but wont starts. the spark plugs keep fouling with fuel. when i removed the fuel pump fuse. it started up. i did a compression test i got 120 psi. what do you think?
Hey Eric whats up with all these 2 min, 3 min, and 5 min vidieos where are the 20 min and 30 min videos? Youre my favorite youtuber and it sucks i only get to watch your new vids on friday and monday but it sucks even worse when the videos are so damn short. Bring back tool reviews or something PLEASE!
I recently moved into a new house and haven't had as much time to edit, that's why the videos have been 'short' lately. Next week you get a long video. That said, I'm likely going to change the format to include more short videos. They get more views, and ultimately that's what this game is all about. Sorry, but the RUclips algorithm is the law these days.
One more thing. It takes hours, and I mean hours, often days to complete the edits on the 'long' videos. After all that work to only see 20K views for a channel with a million subscribers is disconcerting. Hardly seems worth the effort. If you want longer videos, get your friends to watch and watch regularly.
Wow eric the car guy actually responded. Man im super grateful for your response and i just want to apologize i sometimes forget everyone has there own problems to deal with most of the time, but im currently in school to become an automotive tech and everyone in my class watches your videos. But as long as you keep making videos ill keep watching! Id make a suggestion on how long it takes to edit videos is get someone like ,bitwit on youtube, to build you a dedicated computer specially for editing huge videos!
EricTheCarGuy it would be good to try bit of both short and long since sometimes it depends on how much time I have to watch a video. But when I need to repair something I love the long detailed videos and who you are in all your videos. Maybe try 3 short easy to make short 3-10min videos a week and if starting to work out try fit a long one in every now and then. You just need to make it cuz your one of the best ever RUclipsrs.
I measured Valves on a 2010 Hyundai Accent to see if any were bent, timing belt broke. Visual they look fine however I found 2 valves with stems out by .010. Do valves stems have to be perfectly straight with no deflection?
I like that 90 went from not so good to excellent in no time. I like the explanation though.
I was thinking the same 😂
Presumably the low normal compression figures are because it's a turbocharged engine.
Possibly.
I understand your logic but that’s generally not the case in my experience. Probably because it’s German and they wanted to be different! Silly 13mm bolts and weird spark plug threads.
probably more the high quality hose supplied with said tester, they way they flex and expand during testing ;)
throttle bottle I have the same one and can confirm that the flex isn't bad, and that it reads pretty accurate.
Normally forced induction engines have lower compression then naturally aspirated engines to compensate for the extra air that consequently increases the compression during acceleration,
otherwise dependability would become an issue do to the engine running too hot in the combustion chambers
and remember to ring that bell!!!!
Great video. Might be worth mentioning that if you don't have a leak down tester, you can pur a squirt of oil in the offending cylinder and test again. If the compression comes up it is more likely going to be on the bottom end, if not it's more than likely the valves.
Absolutely. I cover that in the compression test video linked in the description.
I dont like this method. Auto parts stores all over the place rent leak-down testers for free and I believe its more than worth the trouble to do the proper test.
I have had several cases of extreme carbon buildup on the exhaust valves (I live in the city, stop and go traffic) where this method would cause a rise in compression and give a false diag of bad engine when it just needed a head job.
Samuel Michelson Did you watch the video or just comment? I believe I mentioned at the beginning and the end of the video that a leak down test would be best, but this can get you started. Also, if you watch the leak down video linked in the description I show how you can use a compression tester to perform a leak down test. Thanks for your input.
EricTheCarGuy, yeah, I watched the video. Did you read my comment thanking you for telling people about leak-down testing? I was referring to my dislike for people putting oil in the combustion chamber and seeing if it changes the compression readings. I dont think there is any useful information to be gained from doing this as per reasons already stated.
Samuel Michelson No I didn't. Sorry I missed that. I don't have an issue with putting oil in the cylinder. For me, if you find a big leak, you know it's coming apart anyway. Thanks again for your input.
You’re speaking my language now. Lost my hpfp, cam shaft sensor was the codes. Replaced both, and grgegrgrhrhrh. Take off the cover, timing chain exhaust sprocket sheared off, and the chain was broken. When it died driving, there was NO significant sound or noise at all, no shaking nothing just.. dead car. I’m hopeful, that the chain broke upon my attempt to restart. As there was never a fire.. just cranking for a second. Then noise then nothing. I am willing to replace the rods and head gasket etc. and your videos will be my Bible. I need to repair this car so bad. I gambled when my last one blew up, and was toast, hopeful for a decent long term ride. I did get 30k miles before it failed
This is the type of video I enjoy most, although I'd never even consider buying a Mini.
usmale47374 he could make a special
@@type2523 ggg:
Compression tests are useful to diagnose a myriad of cylinder problems, as low compression could be due to bent valves, worn valve seats, leaking head gasket or worn out piston rings.
As you said, it is one step to get clear results of an engine failing, not necessarily bent valves.
my desk is shaking from that idle XD
VOTE FOR ERIC!! Eric, you should enter this video into the Cardone Tech Video Contest. I'm positive ALL (well let's not include the haters, lol) of your subscribers would vote for you!!!
That would be cool. I wasn't aware of the contest. Thanks for the heads up.
GREAT, I'll be looking out for your video!!!
That idle looks solid to me. Job well done!
Thank you. You said, "you can rent compression kits", I didn't know that and I need a kit to check my car. Good to learn something new, everyday. Yesterday was "leave Mary alone". :-D
Bent Nickel yeah pretty awesome most major stores have a few tools to rent. I used a spring compressor before help a ton.
Always a pleasure to watch and learn from your uploads Eric. No heavy metal, expert knowledge/teaching and a sense of humour make your channel my first stop. Thankyou, and greetings from Western Australia.
Question: “How To Find Out if Your Engine Has Bent Valves”
Answer: Ask if it’s been dropped on the garage floor. 😂
No I didn't do that. 😉
Or if it's been over revved, or had a timing problem like jumped teeth on a timing belt or had a T-belt snap. (On interference engines)
Or if it sounds like a diesel or not?
Or if the mechanic remembered to torque the crank bolt. ;)
The man tell us that he forgot to torque the crank bolt , he is honest , so don't be rude
Good job Eric. If anyone needs to see the leak down test I saw it pop up in the i on the top right. This is accessible at any time during the video clicking or tapping on the I. Pause the video and it shows up.
Or just click the link in the description.
Keep in mind every harbor freight compression testers i have purchased always read low (4 of them) but zero is zero lol
pretty sure it's the "hose" more than anything, if you watch the hose when cranking closely, you'll see them really expand and contract...... (way too soft/flimsy)
Also the check valve is up in the tester body by the gauge and not down at hose ends, which means the "volume" of the hose becomes part of the total cylinder and head volume. (wrong location for accurate readings) it's the same as having lower compression ratio due to having larger volume head chambers, lower piston deck height or head shims/thick gaskets.
I don't know the total volume of the hose or adapters, which appears to be large overall, so I wouldn't doubt if it's skewed by well over 30PSI ;)
when you replace your spark plug with just tiny compression tester fitting (like in this video) the compression ratio decreases in your cylinder. Because the fitting is a lot shorter than a spark plug.
Hence the low reading on the tester.
Thanks for the new video Eric. I as well did a compression test on my 96 gt and the results were stunning 180psi 1,2,4,5,6,7,8 but #3 had 135psi. Time to tear into it
i bought a cheap cavalier with similar compression results (i compression test cars before i buy them), but hey, it was cheap. It ran fine for several years before i scrapped it for other reasons.
Harbor Freight to the rescue! l know your not a fan of their stuff, but it's convenient and cheap! Above all l am surprised it had a fitting for the Mini! Useful info. Thank you. Looking forward to the engine tear down.
Yep...glad it did. I have one too.
Not to mention....it lifetime warranty on hand tools and most others have a year or 2. And they replace with no hassle at all. I took 3 brake bleeders back 1 after another with no questions ask
Thanks for the video Eric!
Eric has mentioned liking Pittsburgh Pro tools in previous videos. He switched to a different brand of engine stands during the Fairmont build.
I love your explanation in the walk-through with your videos and that’s awesome I just had a timing belt jump and didn’t know really which way to go
I just have the same problem, same n14 engine. same Cylinder 3 has 0 psi and the rest of cylinders have the same pressure. Happy days! Thanks Erric!
The car that just keeps on giving lol
Keeps on giving, up. Or is this before the engine swap?
He never swapped the engine, but it was after changing the timing chain.
He forgot to torque the crank pulley bolt, and this happened.
I don't need that kind of giving catch my drift
@@panzerveps ok. Yeah I haven't kept up I knew he did something. Costly mistake. One time I put the crank pulley on backwards on a Honda and broke the teeth. My $350 car turned into $400 real quick.
Haha! This Mini is that gift that keeps on giving through the whole year, Clark.
Eric you are a badass. Cause that car can't die with you. You are the aumotive anti-Grim reaper in that sense
An amp clamp with a pico scope and a relative compression test also can do The same thing.
Just one cylinder to plug into and all cylinders are tested at the same time eliminating a battery getting weaker skewing tests. Though a battery charger is a cheaper way to increase accuracy. Just use a multimeter and test the next cylinder when the voltage is the same.
Yes it can, but not everyone has access to that stuff, and if they did, they probably wouldn't need this video. 😉
to my experience variable camshaft and electronic throttle bodies can greatly influence a compression tests.. on some engines you must use a scan tool to activate a compression test function which will not only cut off fuel but will also fully open the throttle plate... just pressing the pedal will not fully open it in alle cases
Excellent point.
I've gotta find a tool that enables this function! Hopefully it's compatible. I have an older scan tool, but I'm sure I've never seen this feature. I'll just have to get the -special Schwaben one- Foxwell NT510 for Minis (and BMWs, RRs).
Eric, this is somehow unrelated but the idea popped on another video: car electrical connectors. For some bloody reason, I haven't met a single mechanic who changes the connector housing when it's broken. Everyone makes a ghetto repair with tie-ups or electrical tape. Connector housings even for mercedes or audis are like $2-5 each and it's quicker to cut the old housing with pliers, check the pins are OK and fit a new connector. Click, brand new. Even on dealerships they never fix them properly. I struggled with my broken maf connector for years only to discover the housing was €3.61.
Just an idea for discussion.
Hey eric, I love your videos! I have learned so much from you in the last couple of years. I do have a non automotive question though. What camera are you using? Its SO good!
Designed by the French, manufactured by the Germans and assembled by the British. What could possibly go wrong!
that was a good one , i once owned a renult that was funny....
This is an r56. The r56 is shit. R53 is much better
Use a bore scope camera in the up position so you can see the valves rotate the engine with a breaker bar from the crankshaft pulley and look to see if you have bent valves when they open and close
Thanks Eric. Sorry to rub salt in the wound, but thanks again for showing me all the reasons why I can be happy I didn't buy a Mini when I was thinking about doing so.
Good video Eric compression test then leak down test always best practices but agree leak down test not needed when you can hear it
Thank you so much , I just did a full rebuild on an Audi b9 and it shakes , so this vedio inspired me to start getting dirty again .
Favorite car youtuber.
That engine is one sick puppy. Wric, I hope the repair went well.
Excellent short, to the point and helpful video Eric. Thanks :)
Not surprised that this video would be on an r56! Those N14s are terrible, timimg chain went on my old one and ended up with bent valves.
Will a bad timing chain skew the results of the compression test? Or should it be changed first
Yess another knowledge video by the great one 😁😊
I think i got lucky. I had a crack no start issue i was chasing down on my 98 4v cobra motor which i thought was because of an electrical problem i had from a weird being burned on the egr.
Long story short, while chasing down this issue, i did a compression test and everything was 125-130psi (18cc dished pistons) across the board. I found later the secondary chain was broken. I literally just found the issue so i haven't it'll the head/motor but i think I may have dodged a bullet.
The primary Caine are new and have less than 100 miles on the powertrain but the heads were untouched. Lesson learned, change everything.
It's because there's no Schrader valve on that garbage harbor freight compression tester, they typically test about 10-50psi low
It definitely has a Schrader valve. The gauge doesn't return to zero on any stroke other than compression. That means pressure is retained in the hose and gauge, hence a valve.
@@dylanheadrick3789 there is a Schrader valve in the tester but not on the nipple where it should be. The hose retains unaccounted for pressure.
@@igotmesothelioma the pressure is maintained, So accounted for. The extra volume of the hose is what's not counted for.
@@igotmesothelioma Oh, duh. Thanks for the correction! Shoulda' thought about that.
@@jamesfackenthal semantics can we both agree the compression guage from harbor freight is garbage?
Thanks for this! Mine has a W11, but still gives me peace of mind to hear your interpretation of the results. I had low to mid hundreds the last time I did a test, but I think it may not have been warm enough and I'm sure that gauge hose wasn't tight enough. I'll do another one, along with the wet test, soon enough.
FWIW, the W11 has an 8.3:1 compression ratio
The throttle should also be open, but that's problematic in a vehicle with DBW.
Yeah, that seemed to be a huge issue when I was -trying to run- running the test. I figure I'll just take the intake hose off to make sure it's opening, or have it held open if it isn't.
Thank you SO MUCH for explaining that bit about Leak-Down testing! I was just assessing a junkyard engine for head gasket issues the other day and pulled out the differential pressure guages, really gives you a good idea of the internal health of an engine without tearing it down!
Keep up the good work
My 08 Subaru stalled a week ago on my way to work. Her timing belt snapped unfortunately and I’m worried that her valves may have gotten bent too which is an expensive fix. I won’t know until a bit after Tuesday.
Your vids are always so helpful
Ive got engine management light on my mk4 golf that doesnt want to go away. Had new spark plugs, temp sensor, crank sensor. Diagnosis keeps saying misfire on a cylinder and also temp sensor but they were all replaced just months ago. Car runs fine
For 50 points is it the cylinder making the most noise?
I believe the service manual says anything under 150psi is poor on this engine. My identical car gets slightly over 200psi on my cheap gauge.
I found this really useful and excellent very good straight to the point no waffle great stuff :)
thank you Sir...Greetings from Curacao
I see youre using a pittsburg compression tester, i have the same one and it always reads like 20-30 psi low
Did I miss something? Are you saying that your Mini (BMW) has now bent some of its valves?
I would guess that he did this video a while ago and is posting it now. If not I must have missed something too.
He's mentioned in other videos and in his newsletter that he didn't torque the crank bolt properly, causing the engine to go out of time, bending the valves. This happened after the engine repairs. So he had to take the head off, replace the valves, and redo the timing job. It's all back together and running fine now.
Oh boy, that sucks. Did not hear about that. Well at least whoever gets that car next should have a pretty solid engine, for a mini.
Jon Clark thanks I wasn’t exactly sure what was going on for a minute
Shitting peugeot engine
Someone should also mention that if you havent even heard of Leak-Down Testing before:
It is very simple to do,
Only takes a little while longer than doing a compression check,
Air compressor, differential pressure guage set and a wrench to turn your crankshaft are the only extra tools you will need from doing a compression check
There's also a video on leak down testing linked in the description that covers the entire process. Thank you for your comment.
I had the same issue with zero compression on a single cylinder, when it was dismantled, one of the exhaust valves had a hole burnt right through it!!
Running lean much?
possibly it was bent and not sealing, which make a "cutting torch" passage hole, downhill spiral :))
running leaner makes the engine run hotter.
My nieces car had a similar burnt valve. It didn't look bent on my valve grinder so I think something got between the valve and seat causing it to overheat the valve and melt it. The valve is now included on my wall of oddities with other interesting parts I've removed over the years.
hey Eric like your videos.after you checked the compression in two of the piston chambers do you not have to rotate the crank or cam shaft so that the inlet and exhaust valve seats are closed in the other two piston chambers before testing the other 2.also how much play should the valve stems have in the stem guides.any tips on checking if valves are perfectly straight or if there is too much play in the guides on a pitbike 👍
Good video. But, you should have added that the fuel system needs to be shut down when doing this test. Otherwise, a good basic tutorial.
1:20 was cool. Like he was putting tactical gear on lol.
I really appreciate what you do Eric thank you very much for you answering my question when I sent you Email .
I do like the Prince engine - The turbo models in particular.
I have a 09 R56 JCW with the same problem. Took it to Mini and they said cylinder 3 has 0 compression. They told me I needed a new engine. Once I got the car back the paper work said it is possibly a bad piston ring. I am pretty sure I have bent valves too that don’t require a new $10k engine.
I think the low compression numbers you got are the result of the engine being turbocharged. When the turbo kicks in, and starts making boost, the cylinder pressures will jump dramatically. If you have hi cylinder pressure to begin with, the added boost would most likely, at the very least lift the head enough to blow the head gasket fire rings. Just a thought there. I thought about it a little more. It could also be the result of advanced exhaust valve timing also. That would cause low pressure to. I'm not saying cams out of time, but, again designed do to turbocharging.
The timing on this engine is fine. I just set it before doing the test. Many have suggested that Harbor Freight compression gauges often read low. I think that's the most likely cause. Thanks for your input.
They still have way over 90 psi compression. Should be closer to 150-160.
@@ericthecarguy thanks Eric, your Wilkome. I have watched all the vids on the mini. Including the timing belt change. That's why I said it wasn't a mechanical misalignment. But a designed application of the exhaust timing. To reduce the initial cylinder pressures. I wasn't claiming at all that it was a mechanical timing issue, or bad alignment on your part. I hope this clears it up for you. If the calculated, or designed compression ratio is relatively high 9:1 or higher, you can advance the exhaust valve timing to reduce the initial cylinder pressure to avoid too high pressure once the turbo starts making boost.
Good video. Very straight forward and easy to understand. Thanks!
thank you for your video, I've got a 2007 mini cooper hardtop and your car sounds almost exactly like mine after jumping time. where did you get your compression tester and what brand was it?
If your engine has adjustable valves, you could pull the valve cover and, check if valve lash is in specification.
Yes, that can also work, but it's more time consuming in my opinion.
Well, at least this thing is giving you plenty of content for your videos, I suppose..
Nice video. I wanted to free up the pistons on my SUV that's been sitting on the driveway for the past 5 years due to some problem with distributor. So, I am going to take off spark plugs and pour two teaspoons of engine oil into each hole of spark plugs and turn the crankshaft manually in clockwise after a week of letting the oil sink. So is this the way to do it or will it mess up the timing . And , is there certain limit on number of turns or can I turn it few more times until I feel the pistons being lubricated? I subscribed . Thank you.
Hey Eric, I tried to put a new timing belt on my 2000 Chrysler Concorde LXI 3.2, in my driveway? The belt never broke? Just was doing preventative maintenance. 158,000 on the engine? I lined all the timing marks up, put it back together, no start? Eventually got frustrated, put it on a flatbed, to a mechanic, his diagnosis was bent valves on the drivers side? I bought the timing belt kit, with water pump, installed that, everything spun fine? Would you recommend fixing this car, or try and sell it as is? I put at least $3,500.00 into this car in the last year? From struts, to injectors? Tires, rims, sensors, Evap system, ect.. ect… What would you recommend I do? I had to buy a new car, but this Chrysler ran like a top, before I messed with the timing belt? Can you recommend what to do with this car?
Suppose it isn't a bent cylinder head but a sticking one that is dirty in some way? Could that cause low compression in Cylinder number three?
Without doing wet compression we can't conclude either it's piston rings issue or valve leaking...
If in wet compression, reading improved not improved that means from valve it's leaking..
If reading improved means rings have leak.
If two cylinder HV low compression then gasket burnt..
Eric!!! My cars have Rotary Engines...no need for valves 😉
Yea, but watch out for those apex seals.
THANK YOU Eric!! You confirm my suspicion.
This is exactly my situation after I did a dry and wet compression test (0 on both tests in cylinder 2, on a 95 corolla 1.8 7afe that I bought for my father. But would it cause engine not able to rev more than 3k rpms?
Eric, Thanks for the video and info. May i ask, what causes the valves to bent?
Mechanical failure. I cover that in next weeks video.
To check for bent valves, take the timing chain off and crank the engine over, the number of "thuds" you hear is the number of bent valves.
The timing chain is internal
What could be the problem with a Honda manual it won't stay cranked without constantly reving it if you let out of the throttle it dies
I have a 2.3 l Ford , crank no start .0 compression on 4 cylinders . I pulled the cover and found the cams were out of time ,possible tooth jump. Is it possible on this interference motor that timing jump bent all or half the valves and still continues to crank? I know this is a crap motor . I will try a leak down.
Eric I thought you were going to enter the RUclips Honda challenge. LOL
I don't know what that is.
@@ericthecarguy : it's only like the hottest new trending video on RUclips
Hey Eric I have 91 civic Si it won’t start and backfires out of the intake. I checked timing and it’s good. Suggestion on what to test next? It has fuel and spark
How do you find out what caused bent valves? And how do you prevent it?
Question could you know if a Interference engine is done for if you have low compression 30 on one and the rest are high like 250
Turbo car low compression.... aka helps for predetionation you can run more timìng also... and regular fuel
I have Subaru which is a interference engine and it had 0 comp on cyl 3 and 1 which are on the right side of the engine I checked the timing belt and it was off by 5 teeth. I realigned the belt and it now all cyl show 150. Is it possible to have bent valves and good compression? Do I need to do the leak down test?
Are all the r56's push button start? If so does the computer stop trying to crank the starter or is there some way to tell it to stop?
Outstanding job thanks
I have removed my cam cover but when I refit it knocks the tappets off the valves it’s a polo 6n2 2001 16 valve
I have exhaust valve that moves enough to open but does not fully close. I found by removing valve cover and pinpointing the noise. The valve doesn't close therefore the rocker arm is bouncing off the cam lobe. Is the valve necessarily bent or could something else be making it stick?
ISNT EASIER TO JUST OPEN OIL FILL PLUG??? OR OPEN INTAKE MANIFOLD'S PIPE AND FIIL IS THERE AIR COMMING OUT.
shit, finally my birthday.... no happy birthday from Eric!!!
Just kidding, mine was months ago.
Also, I do that on ETCG1 not on ETCG.
I know... just poking :P
That's a factory turbo engine so there's less compression because there's forced induction. Otherwise engine would probably crap out after 60,000 miles. (Typically an issue people run into after installing eBay turbochargers on their cars without doing anything else to the engine block.)
Was this before you fixed the whole car or after
I'm guessing the engine only showed about 90psi because it's a turbocharged engine that was essentially running NA while you were cranking it.
Yes, that's entirely possible.
Hi Eric,
I have a car with noisy valves KIA Sportage :(,
in your example why would three cylinders be OK and only one have bent valves. What would cause that?
thanks
My timing chain broke when I tried to start my Toyota PU. As the valves were not moving when I cranked the engine to try and start her and my engine was a interference type there is a good chance the piston hit a valve. Would a leak down be worth the effort?
Quick question Eric. I have a ls2 GTO and when it gets to op temp it makes a faint tump sound but when the fan kicks on or if i rev it it'll go away? Any idea? P.s big fan love your vids!
hey eric i have a 2004 mdx that cranks but wont starts. the spark plugs keep fouling with fuel. when i removed the fuel pump fuse. it started up. i did a compression test i got 120 psi. what do you think?
Hi, i got low compression across all 8 cylinders of a porsche 928. All around 80-90psi. Timing is bang on. What could be the issue?
What caused it to bend. If valve spring is ok ?
Is this the same mini you stripped apart?
But if it jumped time by did it only hit the one valve and not all down the row
Hey Eric whats up with all these 2 min, 3 min, and 5 min vidieos where are the 20 min and 30 min videos? Youre my favorite youtuber and it sucks i only get to watch your new vids on friday and monday but it sucks even worse when the videos are so damn short. Bring back tool reviews or something PLEASE!
I recently moved into a new house and haven't had as much time to edit, that's why the videos have been 'short' lately. Next week you get a long video. That said, I'm likely going to change the format to include more short videos. They get more views, and ultimately that's what this game is all about. Sorry, but the RUclips algorithm is the law these days.
One more thing. It takes hours, and I mean hours, often days to complete the edits on the 'long' videos. After all that work to only see 20K views for a channel with a million subscribers is disconcerting. Hardly seems worth the effort. If you want longer videos, get your friends to watch and watch regularly.
Wow eric the car guy actually responded. Man im super grateful for your response and i just want to apologize i sometimes forget everyone has there own problems to deal with most of the time, but im currently in school to become an automotive tech and everyone in my class watches your videos. But as long as you keep making videos ill keep watching! Id make a suggestion on how long it takes to edit videos is get someone like ,bitwit on youtube, to build you a dedicated computer specially for editing huge videos!
EricTheCarGuy it would be good to try bit of both short and long since sometimes it depends on how much time I have to watch a video. But when I need to repair something I love the long detailed videos and who you are in all your videos. Maybe try 3 short easy to make short 3-10min videos a week and if starting to work out try fit a long one in every now and then. You just need to make it cuz your one of the best ever RUclipsrs.
Hi, what kind of fume extraction you use, I thought I saw a portable one. Thanks
good info
I measured Valves on a 2010 Hyundai Accent to see if any were bent, timing belt broke. Visual they look fine however I found 2 valves with stems out by .010. Do valves stems have to be perfectly straight with no deflection?