Oil on spark plug cover and misfire

[David Anderson]

(First time poster here)

I've been having a cylinder 3 misfire for quite some time. I've changed all the spark plugs, coil, cleaned all the sensors (IAC and MAF), checked the injectors and they are all working fine.. still misfiring. Today I pulled off the spark plug cover to check the spark plug and I found oil on the spark plug and oil on the middle of the spark plug. The tip of the spark plug was all burnt out but no oil on it. I believe the burn out on the tip is because of the misfire itself. Not sure where to go from here. The is no oil in the coolant reservoir. Someone suggested that the head could be completely gone but I'm not sure.. considering a compression test at the local shop (for $80!). Anyone know what oil leaking on the spark plug could indicate?

 

[#1taho]

That's just the end of the wire. Not a big deal but you Proberly have a leaking valvcover gasket. are you sure it's oil on the plug?

What year make and model you working with? What engine 5.3 I am guessing. Miliage ?

 

[David Anderson]

That's just the end of the wire. Not a big deal but you Proberly have a leaking valvcover gasket. Have you checked the plugs ?

The plug had some oil on it too but not on the tip of the spark plug. The tip of the spark plug was burnt out.

 

[#1taho]

Did you put new plugs in ?

 

[David Anderson]

Did you put new plugs in ?

Yep, few weeks ago and it burnt out. Thought the plugs would cure the misfire but it didn't.

 

[#1taho]

It is possible you have bad rings or bad valve. Bad valve will burn out a plug fairly quickly. But I can say I have never came across this like the way your describing.

 

[David Anderson]

It is possible you have bad rings or bad valve. Bad valve will burn out a plug fairly quickly. But I can say I have never came across this like the way your describing.

I'm going to change the valve gasket and grommets to see if that Will cure the issue

 

[#1taho]

That won't fix it. I would wait till you get to the bottom of it.

 

[David Anderson]

That won't fix it. I would wait till you get to the bottom of it.

Here's the spark plug from cylinder 3. Oil is leaking from the valve cover to this spark plug so it has to change either way.

 

[#1taho]

Here's the spark plug from cylinder 3. Oil is leaking from the valve cover to this spark plug so it has to change either way.

View attachment 67849

View attachment 67850

View attachment 67851

The plug looks good to me. But I would swap the plug from another Cyilinder. I think you may have a coil problem. The oil on the plug is nothing to worry about at this time. That is another problem. But a minor one.

Did you change the wires when you changed the plugs. ?