Blown Head Gasket?

[ERMedic05]

Hello Everyone,

I have a 2002 Explorer Limited 4WD V8, 126,000 miles. I am no stranger to doing major mechanical work on my baby, as I have already redone the suspension, A/C system, water pump, coolant system, and some other accessory replacements. I just replaced the intake manifold and valve cover gaskets and had to make a repair to the thermostat housing because of a small coolant leak. Today I noticed that apparently I suck at replacing valve cover gaskets, as I have a small oil leak on the left side cover.

In taking things apart to replace the valve cover gasket again, I noticed that the #7 cylinder ignition coil has coolant on it. Upon looking in the spark plug hole I see fresh coolant about half way up the spark plug body. I am assuming this could only be caused by a bad head gasket. I really can't see any engine oil mixed in with the coolant, which is why I'm kinda stumped.

I can replace the head gaskets myself, as long as I can leave the engine in place. I really don't want to pull the V8 unless I absolutely have to with no other options! But before I go tearing down to the cylinder heads I was hoping for some input from anyone. I'm thinking that it is the head gasket, but maybe someone else has another suggestion that I'm not think of.

Thanks in advance and I'll look forward to some feedback.

PS: I have my trust Haynes manual in my garage, and it has yet to really mislead me or fail me on information, but in this case I better make damn sure it's a head gasket before I tear it apart. My wife doesn't like having to wake up at 5 am to give me rides to work!

 

[chopperb]

It maybe left over from the intake manifold or did you remove the plugs when you did the manifold?. Are you getting a misfire? You need to blow the coolant out before it burns the cop out. Make sure you clean the boot also.

 

[ERMedic05]

Hi chopperb,

I left the spark plugs in when I did the manifold to reduce the risk of dropping debris into the cylinders. The cooling system was drained before I did the manifold, so there really wasn't much excess. I thought the same thing that you mentioned about residual coolant from the manifold, but it's really only in the #7 ignition coil; I'm in process of cleaning it out now. After I did the manifold work I took it out for a drive and it did seem to be misfiring. At low idle it sounds and runs great and smooth, but when I get the RPM's up it sounds and feels like a misfire. I'm hoping that cleaning the coil will help with that issue if it is from the coolant build up.

I suppose I should clean it up and drive it to see if in fact it is a coolant leak or just residual liquid from the manifold work. Probably would be a much easier option than jumping into the cylinder heads.

Thanks for the feedback!

 

[swshawaii]

Did you check compression?

 

[xlt03]

Go to Autozone and "rent" their radiator pressure tester with adapters and pressurize the system and see if it holds pressure. Also look closely for the leak. Did you replace the intake manifold or intake manifold gasket? If intake manifold was it Dorman or OEM?