91 Civic engine trouble
 

Hello,

My DD is a 91 Civic, with the 1.5L 16V engine, with 195K miles. It has been running terrible, and after doing a compression test, I found that cyl #3 has less than 30 psi compression (adding oil make no difference). The other three are right at 200 psi. The engine always burnt a lot of oil, about 4qts per 1000 miles.
I would lean towards valve trouble, but would it be possible that the head gasket had been damaged between the cylinders and one of the oil passages?
Any ideas would be greatly appreciated.
Thanks.
Mikel

RE: 91 Civic engine trouble
 

If it was the head gasket, you'd most likely be getting coolant smoke in your exhaust, since the cylinders are encased in circular water passages. With that amount of compression loss, it does sound like it could very well be bent valves, but the fact that it's burning oil makes me think it's the rings, like maybe one of them just shredded. Has your TB ever broken?

RE: 91 Civic engine trouble
 

Hello,
I pulled the head and I found a broken valve. This explains the low compression, but doesn't account for my massive oil usage. The cylinder bores looked very good, with a very minor ridge (didn't measure them). Of course, I can't see the rings, but the three intact cylinders looked the same. Unless the cylinder with the broken valve also had bad rings. The intake runners look pretty oily. Could it be the PCV valve?
Thanks,
Mikel

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