1995 Spk Plug Problem

[blueseasons]

New to the forum. This is my first post. I have had 2 1995 4Runners. On the first one I had a spark plug blow out of the block twice while I was driving it.
Monday it happened to me second 4runner. I had a mechanic replace all 6 plugs on Tuesday. Today Wednesday one of the new plugs blew out. I can see that maybe the mechanic didn't tighten the plugs down correctly which may have caused the plug to blow out today.

My question is, is it common for the plugs on these engines (V6) to work themselves loos over time and if so what is being done to further prevent that from happening? You can also contact me directly at [email protected]

 

[4runner_kid]

I've never heard of this happening or have it happened to me. I would like to hear how many people have had this happen and how this can be avoided.

 

[Iroke17]

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[RpzInc]

It happens when the spark plugs are removed from the heads while the motor is warm or hot. the plugs retain much more heat then the heads because of metal type and density. so when you break lose those plugs while everything is hot you usually weaken the threads on the head. also when you put new (cold) plugs in a hot motor once they seat and are torqued to specs they get stuck because they expand once they get hot. my advice only remove and replace your plugs when the motor is cold.

best fix would be re-thread you can use a heli-coil but its a risky spot to do so. hope this helps, and good luck

 

[4runner_kid]

It happens when the spark plugs are removed from the heads while the motor is warm or hot. the plugs retain much more heat then the heads because of metal type and density. so when you break lose those plugs while everything is hot you usually weaken the threads on the head. also when you put new (cold) plugs in a hot motor once they seat and are torqued to specs they get stuck because they expand once they get hot. my advice only remove and replace your plugs when the motor is cold.

best fix would be re-thread you can use a heli-coil but its a risky spot to do so. hope this helps, and good luck

Well good thing i don't work on the motor when it's hot.