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4.9 spark plug leak


Old 09-13-2017, 11:10 PM
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Default 4.9 spark plug leak

Hey everyone,

As you can tell by the title I have an issue with a couple spark plugs that are leaking. Before anyone asks I want to make it clear that I did check and make sure the spark plugs were tight. The area around the bottom of the spark plugs are bubbling as if i sprayed it with soapy water. This is while the engine is running. Has anyone ever saw this before and is it just a sign that I need to replace the spark plugs. Can the washers that come on spark plugs wear out? The ones that are in it are champions if that makes a difference.

Thanks in Advance
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Old 09-14-2017, 11:12 AM
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Default Leakey head?

Spark plugs with gaskets should be tightened to smash the gasket a little.
If your spark plug is loose the engine will unscrew the plug and blow it out of the hole. Quite dramatically with lots of noise.

I suspect that you washed the engine and there is a little water trapped under the plug and the engine is hot and its boiling it away.

Is stuff dribbling out and down the side of the block?

if a spark plug gasket was broken (I have never seen it) it would blow an exhaust like mark in the hole. You could swap that plug with another to see if the problem moves.
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Old 09-15-2017, 05:32 AM
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The plugs in my 4.9 are tapered not gasketed. I am not sure of a run change but you might want to verify you have the right plugs in there.
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Old 09-16-2017, 09:46 PM
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So I went ahead and put in a new set of plugs and that solved the problem, no more bubbling. Actually what was bubbling before was oil from the valve cover that needs a new gasket (on my list to do). The plugs are tapered, for some reason I thought there was a crush washer on them.

Thanks for replies!
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