I just completed the following repairs on my '84 GS: new Autozone thermostat, new oil cooler seals (to fix leaks), new oil pan gasket (to fix leaks), new hoses, new intake manifold water jacket seals & gasket (to fix leaks), new water pump & gaskets (to fix leak), new fan clutch and new preheater hose. NOW, after countless hours under the hood and flushing the cooling system, the damn thing decides to start running HOT. WAY hotter than before - even with all of the leaks. I have a few ideas, but maybe someone can help here. Could some stray gasket sealer or debris be clogging the radiator (it starts to boil after about 15 minutes on the road)...or could it just be shot after 20 years? Could the t-stat be clogged with gasket sealer? Are Autozone thermostats reliable (no jiggle pin) in rotary engines? If the oil metering pump failed, could it cause overheating? Could air in the system cause this (I can't find a bleed valve)? I would be grateful for any and all advice!

 

Autozone thermostat works fine in my car. In fact it is what finally stopped my car from running hot. Could be a clogged radiator. You can have it rodded or just replace it all together. Good luck.

 

when your car gets to operation temperature, rub your hand over the whole radiator and check if you have and 'cool' spots compared to the rest of the radiator. Thats a fairly easy indication to see if it's plugged in some of the rows.

 

Thanks for the suggestion! I'll give it a try. Of course, rubbing my hand over the whole radiator while it is in a fully assembled car may present a slight challenge.

 

There are no obvious cools spots in the radiator. Could combustion gas escaping through an internal water seal into the cooling system be the cause? There is a very slight amound of dark (brown to black) residue in the overflow container. Also, I suppose I should pull the new thermostat and check to see if it might be faulty. At this point I am hoping its anything but a bad water seal requiring a complete engine tear down.