neilo

I have been chasing a miss around for a while and finally found the problem. I have no compression on the passenger side back cylinder. (3.0) So what do you guys think as far as replacing trying to tear it apart myself and repair whatever i find. Also has anybody had this happen to them. I know the head gaskets were a problem and they were replaced before I got the vehicle. I was wondering if there was something that happened to these engines that was common. Please Help!!!!

76ANTHONY

could be a burnt valve too. could also be rings. but probably a valve or hg

neilo

I dont think it is a head gasket but a burnt valve or bad rings is possible. It does not seem to burn oil so i am leaning towards a bad valve or cracked head maybe. Were these common problems on this engine?

SEAIRESCUE

The 3.0 is hard on exhaust valves by design. Furthermore, the more you drive it, the more the valves recess into the head which ultimately leads to no valve clearance which is what burns the valves. I would check the valve clearances on that cylinder. 0.004 is what I consider minimal cold. If clearances are OK it could be the injector or its electrical connection. Finally, it could be a burned or cracked valve. If you have excess blow-by in the crankcase, you have a bad compression problem caused by a broken piston ring or a pre-ignition caused hole in the piston but that is very unusual.

MY $0.02

Crawdad

It's probably a valve, a leakdown test (pressurizing the cylinder) will tell you if it is the exhaust. It would also probably be a good idea to pull the heads and check valve clearances.

SLOWBOOST

easy way to tell if its in the cylinders or the head is to squirt a little oil into the cylinder and test it again.. if it stays the same its above the block, if it raises the rings/ or piston is bad.

neilo

It was a bad valve. Got a rebuilt head and installed it now the dang thing wont idle. It runs ok above about 1500 rpms but will not idle on its own.

thook

Maybe a vacuum leak.

76ANTHONY

check your timing, and then check for cavuum leaks.

thook

Yeah...cavuum leaks suck! They're even worse than vacuum leaks...

abecedarian

were valve adjustments done after the head was installed?

neilo

what is needed for valve adjustments it didnt seem like there was any way to adjust the valves since the cam basically rides right on them. The timing looks right or very close from what i can tell but it is idling very erratic and almost not at all. I amgoing to take the timing cover off just to double check everything in there.