159 2.4 20007 plate
19,500 DPF/EGR by
AO Silver Member
Join Date: May 2009
Location: United Kingdom
I have never done a compression test on one of these but would expect 170 - 200 psi and I have seen some really well run in engines produce 220-230psi. I would be quite disappointed with less than 170 and worried with anything less than 160. Also all cylinders should be within 5% of each other. The actual pressure will depend on how far along the "run in" and piston ring sealing road it has got.
It's a shame that you didn't compression test on initial build as you would then have a datum. However, it's only the paranoid nerdy types who would bother. It says something about me that I do!
If pressures are low a small squirt of oil into the cylinders may significantly increase the pressure. If it does that is the oil improving the seal between piston and bore and showing the culprit!
How many miles have you done since the re-hone or glaze bust?
NOTE: I have assumed that the compression ratio is 10:1. Pressures 10-15psi lower for 9.5:1
Last edited by kandlbarrett; 05-02-12 at 12:05.