compression test on 2000 volvo v70

Post by **famfeld** » 24 Jul 2016, 17:02

I just did a compression test on my car and found cylinders 1-3 and 5 at 210 psi, but cylinder 4 was at 170 psi. I added some oil to cylinder 4, then it went way up over the scale of my compression tester. I have had this car for 5 years and have taken good care of it and driven 25K miles. I have always had a slight engine vibration that after changing motor mounts and several other things am now thinking that could be attributed to the low compression in cylinder 4. Is this reasonable?
Any ideas?

Thanks,

-Feld

Post by **FLXC90** » 25 Jul 2016, 15:15

Yes, the one low cylinder could cause a stumble or burble at idle and low power. If the result of the wet test is accurate, your rings are the weak link on that cylinder. How many miles on the car when you got it? (25k ago)

I would suggest a cylinder pressure leakdown test by a trusted shop who can tell you where the leakage is occurring. The oil may have been enough to fill a small H/G breach.