Okay so I'm new to the jeep world but I've been putting a lot of work into my 89 cherokee. The latest thing I've done was the compression test because I'm convinced I may have worn piston rings. The reason I think that is because I have one spark plug in my #1 cylinder that is covered in oil which I automatically assumed was the piston rings, however the other spark plugs are perfect. but here were my readings so far, I'm hoping I did it correctly.

Cylinder #1- 105
Cylinder #2- 130
Cylinder #3- 140
Cylinder #4- 150
Cylinder #5- 115
Cylinder #6- 115

I added a little oil to the #1 cylinder and that made the reading on that one go to about 115. Since it went up a little, does that mean my rings are definitely worn?

Just looking for a little feedback so I can figure out if my problem is in the rings or head or what, and im curious to see if you guys think my engine is gone or what? This is my baby and I'm willing to do whatever it takes to keep her alive.

Thanks.

 

If the reading goes up after adding oil, it usually means the rings are worn. How is the engine running? Oil on the spark plug could also mean the valve guide seals are worn.

 

It runs alright. The only problems I really notice is a lot of hesitation right after start up and it will randomly hesitate here and there, but I assumed that had to do with the oil covered spark plug. That and it's loud like a diesel and it never seems to idle right. I've done the tune up and everything. The only thing that made me think it may not be the rings was because she never really smokes or anything, the only smoke I have is coming from under my oil filler cap. Is that still a sign of worn rings?

 

It being loud is an exhaust leak more than likely. Do you have some blue smoke on startup after sitting over night? If so that is either worn valve guide seals, or valve guides. Yes your rings are worn a little if it went up by 10 psi, but not much, you have 2 that are higher than the rest, but with those readings I would think the engine would run fine.

 

I haven't seen any smoke at all coming out except for under the oil cap. And that's only after it's been running for a while. that's why I've had so much confusion on what's going on with it haha. the manual doesn't say anything about worn piston rings without mentioning smoking and I haven't had any of that.

thanks for the help though!

 

Are you checking compression with throttle fully depressed? That will change the readings quite a bit. Also Steam coming from the oil cap could be lack of driving and condensation burning off, or a possible headgasket issue, like a really small leak and it is burning the few drops of coolant off that are getting in the crank case.