I found this gunk on my passengerside rear most plug. The plug was much more difficult to remove than the others. This is the only plug with crud in the threads. What could this be? When I try to reinstall a new plug, I can not get it to thread easily. Could this be dirt that somehow got in to the plug hole between the plug and coil? When I removed th plug I ground the dirt into the threads?


It has kind of a greasy consistency to it... maybe from the dielectric grease?

Please help me figure this out..


TIA,
Ryan

 

pic 2





Ryan

 

do you wash your engine a lot?

Will

 

It looks like you have been getting water down in the hole causing all of that rust.

 

I have only cleaned the engine bay once, but I did drive the truck in two Buffalo winters, which were pretty sevre in terms of snow and salt and other assorted garbage.. this could very well explain the water getting in to the plug hole. What do I do next? I need to get the new plug in, but I don't want to screw up the head, or drop crud in to the cylinder.


BTW, thanks for the quick replies.. I have a sinking feeling in my stomach, every time I do something to the L, I find all kinds of problems (this all started with replacing the air filter and noticing all the oil in the elbow)



R

 

Looks like that plug was replaced and someone went crazy with the anti-seize compound...

 

The #4 coilpack seems to be the one that goes bad in many of our trucks. There is a coolant hose just above that particular plug/coilpack that leaks in some trucks. Tighten up the hose clamp on that hose. This may be your problem.

 

It may be antisieze or rust but I'm guessing it's 'varnish' that comes from fuel leaking past the threads???

"It has kind of a greasy consistency to it... maybe from the dielectric grease?"

The "greasy" feel is what makes me think it's 'varnish' as well as the color.

You can buy a thread-cleaner from Sears, etc. and run it down into the plug threads. I wouldn't worry about grit, etc. falling into the chamber as that would be blown out with thexhaust.

Dan

 

Thanks guys, I'll try the thread cleaner.. I immagine it looks kinda lika a metal bristled pipe cleaner?

These are the stock plug I removed, and I am the original owner, so that rules out the anitsieze unless it gets put on at the factory.

I will check the hose to make sure it is tight and leak free...

Assuming this is gas leaking past the threads, will a new plug solve the problem, or does the head have to get helicoiled?

Is there some sort of liquid gasket type stuff to put on the threads of the plug to seal up the chamber?


Thanks,
Ryan

 

Not a "brush" but looks like this. They don't all look like that but close. They will have steel, cutting-type threads to clean out the dirty, varnished head threads. No helicoil needed yet--I hope? Do the cleaning carefully so as to not ruin the head threads--go slowly--by hand-tightening at first.

When you've got the threads as clean and smooth as you can then the new plug should run in by hand-tightening most of the way. Run the plug in as far as you can with no 'torque' applied. Once the plug is 'seated', turn the ratchet/plug 1/16th of a turn more . That's all! I use antisieze on my plugs but some don't. Mine have been in 20,000 miles with no problems.

Dan

 

i just used one of those today on a friends firebird.. i don't think it'll fit down in the spark plug hole on our trucks.. will it?

 

this happens in expiditions with like an aircon line above the #8 plug that leaks water down into the plug. Dunno if that line is there on the lightning.

 

my back plug on the drivers side was rusty when i pulled it too. prob no big deal

vinny