Rebuilding A "Wrecked" BMW from Copart! Part 2
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- เผยแพร่เมื่อ 9 ก.ค. 2024
- I wanted to run some test to verify what the actual issue is with the Copart BMW engine. Looks like we have super low compression in Cylinder 4, everything else seems to be ok which is a good sign! Lets do some troubleshooting.
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Hey, nice project. Well, that's unfortunate. What do you think was the issue for the 4 th cylinder to have zero to none compression? Oil starvation on cyl. 4?
But I like your video. Currently I am restoring a BMW too. But its a little bit older, its a 1999 E39. 😅
Thanks! With the compression and leakdown test looks like cylinder 4's piston rings aren't sealing. The rings might have broke or the ringland where it sits might have cracked. When the engine is warm I get about 90 psi and the car is drivable so I know there isn't a giant hole in the piston. The valves seem ok as well since the leakdown didn't show any air escaping from the intake.
I'm just waiting on parts to start tearing into it.
@@projectrandomCO What about carbon build up on the piston rings? This could lead to not sealing up when cold, but when the engine is warm, they expand which could be why the engine has 90 psi when warm. (90psi is actually also quite low.) So you could try to squirt a little bit of special Carbon cleaner in the spark plug holes, let it sit for a bit (maybe even a few days). Then take out the spark plugs again, start the engine so that the cleaner comes out. Especially when the car sat for a longer period, this could be effective. I would prefer that way, before taking the engine apart.
I'll check it out, I haven't started tearing it down yet, I am still waiting on parts for the timing. Not sure of the history of the car so it might have been sitting for a while. I'm leaning towards overboost and some bad rings but I'll let it soak and see if I can get a borescope down there to check the piston top and valves.
Hey! I picked up some berrymans B-12 and did a 24 hour piston soak with no luck. Added more every 6 or so hours and plugged it with the spark plug so it didn't evaporate. Cleaned the piston head real nice but still no compression when cold. I did end up ordering forged pistons and rods so just waiting on those. I'll probably have a teardown video coming soon! Thanks for the suggestion, definitely adding that to my bag of tricks!
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