Wondering if anyone out there could give me any clue what is going on with my engine. I have a 86 non turbo automatic with 180,000 miles. Engine seems to run fine for first hour or two (normal operating temp, etc.) After that period of time engine will begin running excessively hot with what sounds like a valve pinging when engine is under load, idl is also sometimes affected but not much.

These are a list of things that I have done to engine.
Change timing belt
Water pump
Checked timing
spark plugs & wires
cap & roter
new thermostat
new radiator cap
cooling system flushed
air cleaner

Would greatly appreciate any ideas, thanks.

 

Id suggest the cylinder head temp sensor. Its between the FPR and the AC compressor. It has a yellow connector. It takes either a 22 or 21mm deepwell socket.

 

Thanks for the reply. Is this the coolant temp sensor or something else?