My friend has a 89 Civic Si and one day it was running good and the next it was running bad. Its not throwing any CEL's or anything. It sounds like its running on three cylinder and clugging. I checked the spark on all four cylinder and its fine. We did a compression check on it and three cylinders made 190-195psi and the other one made like 20psi. Now his car burns some oil and has for some time, but before all this, his car still had good power. The thing is that when the rings go bad on an engine I thought that it would slowly lose compression over time, not all at once. We also took that valve cover off and look at the cylinder's valves and everything. We rolled the car with it in gear and watched the valves go up and down, so it didn't drop a valve. Anyone have any suggestions?

 

anyone?

 

I think that it could be the rings, I don't see why when the rings went that it would lose compression slowly and not all at once.

 

Maybe is your head gasket is broken or the ring.so check if the oil go in the radiator or check if the prestone go in the oil.if will go the head gasket is broken

 

This sounds like a head gasket issue. Any oil in the coolant? Or vice versa? At this point, it's probably worth it to pull the head to check. 20 psi sounds like a head problem. Rings probably wouldn't leak that quick

~Rick Shank -- who's changed a ton of EF head gaskets.

 

if it smokes as well as losing a cylinder I would guess either a headgasket or a broken ring.

 

Your next step is to do a cylinder leak down test on all the cylinders, this will decifier if it is a broken/damaged ring (leaking past) or leaking through the valves.(burnt or need to be refaced) (or possible head gasket).

Also another thing you can do is, add a squirt of oil to each cylinder say 2-3 oz's and redo your compressor test, if the weak cylinder goes up ALOT more then likely it is rings.

Check for coolant in the oil, and oil in the coolant. This is signs of a blown headgasket.

Jeff Frank