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Dodge Repair/oil leak in cylinder


04 caravan 120,000 miles has oil on spark plug tip in cylinder 3.8 engine. what are the possible causes.

Hi Don,
It could be due to oil leaking around one of the valve stems, or to worn piston rings, or to a head gasket leak next to that cylinder. The first thing to check would be the compression of that cylinder and compare it to another. It should be around 100 psi at least. Are you also loosing coolant (excessive white smoke from the tailpipe when starting from cold)? If so that would point to a head gasket leak. Otherwise I would suspect oil leaking around a valve stem or the piston rings.
You can check the rings by adding a teaspoon of oil to the cylinder and then rechecking the compression. If it goes up noticeably that would suggest bad rings. Otherwise, then valve stem seal would be the likely cause.


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Roland Finston


Get a Free Fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

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