Please Advise, i just replaced my head on a 22re engine in a 94 toyota pickup (4x4) due to a defectively machined ramanufactured head. the machine shop said that the heat plug was popped, meaning that it had overheated but even after the head gasket was blown it never overheated according to the temp guage. the guage seems to work fine with one exception, occasionally the needle would fluctuate between cold and normal (from normal to cold and back in about a second, over and over) then just stop doing that, all the time running fine and never going past the normal postion. the coolant level was fine during that time. any ideas what could have caused the fluctuation and how i can make sure the temp guage is always working properly since it usually seems to work fine? i know the first thing anybody says with a overheating problem is to change the thermostat, but at this point i don't think it's overheating, i just need to make sure i can see it on the guage if it does overheat since the machine shop says the heat plug was popped. I have a chilton's manual but no real help for this problem and, of course, the parts dealers at toyota are rude and don't try to offer any help.
shane