Reply With QuoteAnything over 140 is considered acceptable. Look for an even spread with no more than 5 lbs variance across the holes. Make sure they do it warm and hold the throttle plate open.
Grand Master
compression check on m30 *update*
i'm going to get it done this weekend.
since we run 9.0:1 what should i be
looking for? 160ish? i've got a 91 535i
new head gasket, and 150ish thous miles
Last edited by bahnstormer; 07-05-2004 at 01:50 PM.
Grand Master
Anything over 140 is considered acceptable. Look for an even spread with no more than 5 lbs variance across the holes. Make sure they do it warm and hold the throttle plate open.
Bellevue WA
90 535iM - not much stock remains. 3.7 liters, ported head, cammed, 3.73 diffy, M5 brakes, MAFed, yadda yadda yadda
86 Porsche 951 - Track Toy
Major Contributor
New HG? Was the head milled too? That might give you a little higher compression reading. I got around 170 on my 180k M30, with original HG AFAIK.
The throttle body has a pretty handy little nipple that makes clamping the throttle plate open for the procedure very easy.
I've also heard a 5% variance is acceptable, which would be more like 8-9 psi if you're reading in the 170 range. Just depends on who you ask, but they should be very close together.
Grand Master
ok the guy didn't clamp the throttle plate open....i'll have to do it again
1 - 150
2 - 155
3 - 155
4 - 160
5 - 155
6 - 160
oil pressure is 2 bar at idle and goes up to 6 with revs
all the plugs are nice and clean (with EAT chip)
Grand Master
do u think this kind of compression is ok?
Green Beret Special Ops
compression is perfect!
Good to go, happy trails!
95 E34 530I V2.37
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