p300 random miss fire
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From: Oskaloosa Iowa 52577
Year: 1997
Model: Cherokee
Engine: 4.0
Originally Posted by tjwalker
Re-do your compression test on those two cylinders. If they are still low, add a tablespoon of oil and do it again. If the compression comes up, your rings are shot. If the compression remains low with oil, that cylinder head is going to have to come off.
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From: In the middle of Minnesota!
Year: 1999
Model: Cherokee
Engine: 4.0
Caused by excessive oil entering the combustion chamber. This is often caused by piston rings or cylinder walls that are badly worn. Oil may also be pulled into the chamber because of excessive clearance in the valve stem guides.
You still need to do what I told you earlier in order to figure out ROOT CAUSE.
Get a compression test on cylinder #2. Then add a tablespoon of oil, and re-do the compression. If the compression comes up AFTER you added the oil, your rings or cylinder walls in that particular cylinder has a problem. If the compression doesn't change, suspect a problem in the cylinder head; valve related.
You still need to do what I told you earlier in order to figure out ROOT CAUSE.
Get a compression test on cylinder #2. Then add a tablespoon of oil, and re-do the compression. If the compression comes up AFTER you added the oil, your rings or cylinder walls in that particular cylinder has a problem. If the compression doesn't change, suspect a problem in the cylinder head; valve related.
Last edited by tjwalker; Mar 5, 2012 at 05:28 PM.
CF Veteran
Joined: Nov 2010
Posts: 5,840
Likes: 117
From: In the middle of Minnesota!
Year: 1999
Model: Cherokee
Engine: 4.0
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