For some reason, pontiac thought it would be a good idea to put a square bit plug where the fan temp switch usually goes. Does anyone know what size that bit is? I can't find it at any store.
The heads are interchangeable left to right... are you sure the head on the other bank doesn't have the plug already removed?
I have seen one engine that was totally assembled and installed before they realized they'd put the heads on the opposite banks. They couldn't get the plug out so they ran a pair of wires across the engine to the temperature sensor at the right front of the engine.
Originally posted by fierofool: I have seen one engine that was totally assembled and installed before they realized they'd put the heads on the opposite banks. They couldn't get the plug out ...
Personally, I've never been able to get that plug out and neither has the machine shop where I get most of my work done. They're in there good and tight with 30 years of corrosion in the threads. My experience has been that the square socket in the head either rounds off or the tool does.
Our mechanic that installed my 3.4 got the plug out of mine. The engine had good compression so we didn't want to pull the heads. I don't know how he did it, but he did. Freezing it with AC refrigerant and whacking it with a brass drift and small sledge can sometimes break them loose. Then use an impact wrench. I've used that method on the same type plugs in other applications.
[This message has been edited by fierofool (edited 02-13-2015).]