The plug in line with the master cylinder on my Tundra is suck. It will actually turn, with a consistent 75 ft lb of force. Its not loosening, just turning.
In another thread someone suggested that the 4.7 aluminum head has a steel insert the plug threads into and that I was probably turning the insert.
I am not sure what to do. I figure the head needs to come off. If the insert is turning, its just going to keep doing so. If the threads are buggered it will need to be fixed. I suppose my first step is to soak the plug with penetrating oil (pb blaster, liquid wrench) then hit it with an impact.
The plus in there probably have 40k on them, and I always use anti sieze. The motor has 130k on it and runs like a top.
Thoughts or suggestions?