Compression Test Results


My friend and I ran a compression test on our cars on Monday.
My results on the second time around:
Cyl 1: 165
Cyl 2: 165
Cyl 3: 155
Cyl 4: 180

Am I looking at a rebuild here? I've read on the guide that came with the compression test that a 20 PSI difference between 2 adjacent cylinders is indicative of block warp. Elsewhere I've read that it has to be at least 30 PSI and yet elsewhere a 10% difference in compression indicated block warp also.


Slow Driver
potential causes would be cylinder rings, head gasket, messed up valve, stuff like that. A rebuild would do you good. It's not as hard to do as it sounds. I use to be scared of a "rebuild" but it's doable.


I understand. I'm also told that in the event of the surface of the block being warped that a re-conditioning is necessary to ensure that it is absolutely flush with the head gasket. These numbers are before we ran seafoam through the brake booster line, so I need to run the test a second round. Thanks, Slo.

The engine feels somewhat better after the seafoam.
Last edited:


New Member
What are the specs for stock/healthy motor?


Ok. The engine seems to run pretty fine. It picks up quite easily and doesn't stumble. The seafoam worked, I think. I suppose this is something I don't need to consider until I've reached 260,000 or something.