Lowwww compression but timing belt still on track?

Sookys · Post by **Sookys** » June 2nd, 2007, 5:09 pm

A while ago my car's CV joint wrecked so I bought a new one after a few weeks, put it all in, and now as of about 2 weeks ago my car wont start up again. We checked for bad gas, a whole list of things, then we tried a compression test, I think the standard pressure was something around 185 lbs in the repair manual, my car averaged about 50 lbs of pressure. So we thought the timing belt was out, popped everything off, and it was all in place. The only logical explanation in my mind is a blown head gasket, but the car was running fine before it broke, nothing the matter with it other than the CJ joint. I started it about a week after the CV joint broke, it was boggy as hell, just ran like crap, and now yeah, it wont start. Help please? =)

Tunes67 · Post by **Tunes67** » June 2nd, 2007, 7:15 pm

Just cause your timing belt is still in place doesnt mean that it hasnt jumped a tooth or two. Its also possible that the timing belt hydraulic tensioner went bad.. unless you really checked the belt well.. I'd go back and take another look at it. Also.. if your averaging 50 PSI on all 6 cylinders.. well.. I might consider 1 blown head gasket.. but blowing both head gaskets in the same manner on both sides of the engine at the same time? Eh.. If that happened.. buy a lotto ticket tomorrow cause thats some damn LONG odds right there. Your timing belt is still your most likely culprit.

Tunes67

Sookys · Post by **Sookys** » June 6th, 2007, 9:32 pm

Well thats what I meant, the timing belt was all aligned to the right spot, it hadn't skipped any teeth at all, so yeah, low compression but everything is right where it should be.

lakersfan1 · Post by **lakersfan1** » June 6th, 2007, 10:23 pm

Is it cranking at full speed? If the battery is dying, or something is wonky with the power/starter, you will read very low compression. You need the speed of a healthy starter to get proper compression numbers.

Sookys · Post by **Sookys** » June 7th, 2007, 10:34 pm

We turned it over the other day to run the compression numbers. It SEEMED to turn over quick enough, I mean, for those numbers it would have to be turning over very slowly, would it not?