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How bad are these spark plug issues

V

VTXrider

Full Member
Joined
Mar 21, 2018
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16
I changed my spark plugs yesterday. I'm not sure but I assume that this is the first time the truck has had plugs changed, 2003 with 140k miles (I've owned it about 6k miles)

What are everyone's opinions on these two plugs. One with oily threads and one with the insulator cracked. I'm thinking that the insulator being cracked is not so bad given the age of the plugs but not sure. The oily threads might be a worse issue? My goal is to spend as little as possible to keep the truck in good running condition. The truck will see about 3-4k miles per year but much of that is towing a boat or Home Depot type runs hauling payload.
 
How do the valve cover gasket look?

That sure looks to be a lot of oil on the top side of the spark plug.
 
what cylinders did the come out of?
 
Should have paid more attention but I believe it was #3 cracked insulator, #4 oily threads
 
VTXrider said:
Honestly I couldn't see, I could use a mirror to try to see better
Click to expand...

A mirror and a good light source or maybe a bore cam to get to the really tight spots, might be a good idea.

Bore cams that work with your phone are fairly inexpensive and can come in really handy.

I have two and I have found several uses for them around the vehicles.

If the valve cover gasket was leaking oil above the cylinder with the oil covered spark plug, that could account for the oil covering the part of the spark plug that is above the seat and threads and external to the combustion chamber.

I would think you would be able to see if the valve cover gasket was leaking oil at that location, though.

I would not think an oil leak on a 17 year old engine would be all that rare.

I suppose you could get oil to blow past the threads and seat to work it's way up and accumulate on the upper, external part of the spark plug.

But, to me that would indicate a poorly seated spark plug and a boat load of oil down in the cylinder.

The cracked insulator on the other spark plug is probably from a poor installation where the spark plug wrench was not square on the spark plug as it was tightened.

I have done that when the angles were difficult, both installing and removing.

Or, the spark plug could have been over tightened during installation or really cranked on at removal.

These are all of the guesses I have at the moment.
 
does it run well with new plugs?

If yes I would not worry and find oil leak above plug which my guess is valve cover gasket
 
Ran fine before and now after. I'm thinking I'm getting slightly better fuel economy also. I do not think there is any oil in the cylinder just on the outer part of the plug and outside threads. The inner threads were dry.

I think it is just a slight leak in the valve cover maybe lose 1 quart per oil change, maybe less.
 
Dirt (trapped by oil) down the side of a spark plug can give an electrical path to the the zap meant to your spark plugs, it's important to keep your spark plugs clean; just as dirt on a battery can cause a short to ground. It's rare, but it happens.
 
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