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-   -   Wet spark plug and running rough (

rshortey 04-09-2012 07:31 PM

Wet spark plug and running rough
I have a 2000 cherokee sport 4wd 6cyd. Today the lower hose burst and the engine overheated. I replaced the hose and refilled with antifreeze and now the engine is running real rough. Kinda like it is mis-firing. It also is producing a strange odor out of the exhaust like natural gas smell. I pulled the spark plugs and #3 was wet with what smelled like gas. I really just don't know where to go from here. I am concerned that the overheating may have caused some serious damage but how do I check? What does the spark plug mean? And the odd smell... I appreciate any help!!!

sctmcly0 04-10-2012 02:22 PM

The natural gas smell is because number three plug isn't firing, sending raw fuel into the exhaust. I wouldn't recommend you to continue driving this until you fix the misfire because you will destroy the catalytic converter and then you will have more problems

MeBoosta 04-10-2012 06:47 PM

I would do a compression test on all cylinders and compare the results with cylinder #3. Give it a dry test, than try pouring a teaspoon of motor oil into each cylinder for a "wet" test. The scores on the wet test should be slightly higher than the numbers you got from the dry.

If you get a really low score on #3 on both tests it usually indicates that you may have a broken head gasket, burnt valve, or bad piston rings.

Since it overheated, chances are it damaged the cylinder head.. Aluminum expends drastically when overheated, from what you told us I'm guessing it's what might of happened.

Like I said man, a compression test would really set you off with the diagnosing procedure. If the compression test gives you good numbers, than the issue is with the ignition system. (spark plugs, distributor, etc..)

Let me know how it goes, I would be glad to help as much as I can.
19yr Old
Entry level Service Technician
BMW Gallery, Boston.

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