talonhead

Started the truck tonight to go home from work, all fine. Got to exit of lot and there was a loud pop and then a nasty noist like a major exhaust leak. Drove 1/4 mile to next parking lot and pulled in (no change in noise or driveability so far). Left it running and lifted hood to try and find out where it was coming from.
Was able to hear the sound pass side rear of intake area. Then was able to feel the exhaust pulse with my hand near the injector/spark plug area of the last cylinder. No visable discharge from area.
Made the drive home (about 6 miles) with only slight decrease in power.
Lifted hood again and got a flashlight to take a closer look. Coil on last cylinder was ratteling around in place. Turned of engine, and was able to get my hand in there and the coil hold down was broke and coil was not attached to plug boot. Will have to check it out tomorrow after the engine cools and I can get a mirror to see.
QUES. Could this be a blown spark plug? If so, and it's the heli-coil thats blown, can it be fixed- or does the head need replaced?
Anyone seen this?
MikeH

Bert

That sounds like a blown plug. It can be repaired with a threadsert. Find a good shop that has the equipment. Many times the plugs are over torqued when they're installed and when the aluminum head expands when it heats up, it pulls the threads.

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Bert

talonhead

Verified #4 plug on pass side is gone, boot also. This SUX!
And my garage is full, with winter coming along.
MikeH

Bert

Here's a link to a past post on this. Coil Pack and Spark plug pushed out 98 navigator

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Bert