130 145 145 145 145 130

[Huff]

So, I ran a dry compression test on my daily m20 and 130 145 145 145 145 130 are the numbers I got back (In order from 1 - 6).. I did some research as to what the issue is but couldn't find for sure if it was a head gasket leak or head warping? There is some oil weeping around the block, no oil in coolant. It doesn't burn any oil (that I can really tell)

Ideas?

[drumad]

You should be concerned with the consistency of the numbers vs their actual values (unless obviously outlandish). I know environmental conditions are a factor. I'm not too familiar with the m20 so I don't know the typical range, however, your numbers obviously indicate something with cyl 1 & 6. Couple threads I've found through google.

Numbers do seem low tho.

http://www.bimmerfest.com/forums/showthread.php?t=136177

http://www.r3vlimited.com/board/showthread.php?t=192617

Check your valve settings perhaps?

[Huff]

Valves where just done and fine. The tempurate was around 70f that day and the engine was completely cold.

I just can't remember from shop class or some book I read what the front and rear being low meant on an inline 6. I thought it was either a warped head (which might have happened over the summer; careless girlfriend move) or head gasket failing

[nrubenstein]

I think a 15psi difference means you ignore it.

[drumad]

I think a 15psi difference means you ignore it.

lol that too. Seems to be consistent enough.

[pwagon717]

#1 and #6 are the week points on the M20 anyways.

[ricerscott]

Usually when I do a compression test I do it with the engine fully warmed up. Then turn the engine over while holding the throttle wide open. Try that and see how your numbers are.

[Jaxx_]

yeah, have the motor warmed up. tolerances are better and you'll get a higher compression reading.

[jlevie]

Repeat the compression test on a hot motor with; all plugs out, a fully charged battery, and the throttle locked wide open. Record the numbers and then squirt a bit of oil in each cylinder just before checking compression on that cylinder. Follow that with a leak down test on each cylinder and post the results.

[Huff]

Yeah, I suppose I need to do a leak down to test to see... Well, if there is a leak..

[lole30]

No more than 10% variance between any cylinders