Compression test results???

[bjl4776]

I finally got around to taking a compression test on my e36 with the M50tu that took convincing to get running, but now won't idle. So in the Bentley is says compression should be between 145-156 but im reading much higher. The compression test while it was cold showed (in order), 210-210-200-230-200-205. These numbers are already pretty high, especially that 230 on number 4. Then i let it warm to operating temp and got 230-235-235-235-220-225. Wow, these are way higher than they are suppost to be, or am I wrong. Could I have lucked out and this thing already be built up, or am I being way too optomistic. If it is built up, do you think the stock DME i put back in it could be the probelm? At least i dont have a bent valve or anything from those readings. Any idea of what could cause them, thanks.

[632 Regal]

I dont know what the normal compression should be on your engine but if those really are higher than its supposed to be the camshaft could be off a tooth. Since you say it wont really idle thats probably the first thing I would research into.

[niall]

yeah this is big time compression, does the car actually drive on that compression??
last time i saw figures like that was on a old vw gti of mine which i had 12.5 to 1 comp, it used to pull about 240psi, so yeah unless you have put 12to1 pistons in it, you have a problem!!!!! like 632regal said, i call camshaft timing aswell

[632 Regal]

the cam would be advanced to raise cranking compression.

[winfred]

that or he squirted a butt load of oil in first


the cam would be advanced to raise cranking compression.

[bjl4776]

i put alto of oil in the cylinders to get it running at first, but that has long since burned off. The car runs at high RPM with that compression, but wont idle at all. My guess is that either the cam is off a tooth, or there are higher compression pistons in it. Are there anyway to test between one or the other

[niall]

well put it up on Top dead centre and check your marks.
i dunno if someone would put such high comp pistons in it,
on my gti i had to run 105 octane at that comp

[bjl4776]

What do you mean, check my marks? I really miss driving a bimmer and need to get this thing roadworthy asap or I might have a stroke, especially with the nice spring weather.

[niall]

check the camshaft timing marks dude, turn the motor
till it is on TDC and firing on No 1 cyl, and check if all the
timing marks line up then you will know if you are out a tooth

[632 Regal]

http://www.realoem.com/bmw/partgrp.do?model=CB43&mospid=47498&hg=11&fg=25

It may only be one cam off and not both...either way you have to get in to it to check it out.

can anyone explain the marks he has to line up and check?

[bjl4776]

yes, can somebody please explain the process of checking the timing for me please?