Compression Test

[Del]

My son did a compression test on the Z3 (just for curiosity as it’s running well and doesn’t burn oil despite 90k miles) and it was:-
cyl 1 190
cyl 2 190
cyl 3 191
cyl 4 190
The Haynes manual (for both 4-pot and non-m 6 pot) just says compression should be at least 142-156 psi. Has anyone else tested theirs recently or have any observations/comments?

[Robert T]

I'm not sure that the actual numbers matter, as long as they are all pretty similar.

Cheers R.

[shootinhoover]

if the numbers are all the same but seem alittle low,squirt a touch of oil in each chamber and test again,if they all go up, then a steady even wear on each chamber is evident.

[pingu]

Don't forget WOT, so cars with fly-by-wire need to have the ignition on.

It's not as simple as it used to be on the likes of RobT's Frogeye .

[Smartbear]

if the numbers are all the same but seem alittle low,squirt a touch of oil in each chamber and test again,if they all go up, then a steady even wear on each chamber is evident.

if a squirt of oil improves the figures it points to piston ring/cylinder wear.
regards