Hey gang, my 86, 2M6 temp gauge went into the red while stuck in traffic…. Back on highway, went back down, I’m sure due to wind. Question… What’s the quickest way to diagnose and fix? I was told, change out the thermostat and test the radiator fan. Thermostat is easy, but not sure about the fan… as always, advice is greatly welcome. also, it does not have A/C.

[This message has been edited by branger (edited 09-18-2021).]

Did your rad fan come on at any point while you were stuck in traffic not moving?

I couldn’t tell if fan came on as it was in the middle of super busy traffic and didn’t know about fan till I spoke to a guy much later… if I just sit with it running in the driveway, will the fan automatically turn on?

I was having this problem...My '85 2M6 would overheat on my commute home from work.....I noticed that the fan would only start running as the car was overheating- not before. So I replaced the original 237* fan switch with a 220* switch...The fan comes on when it is hot our or when I am stuck in stop & go traffic- but not all the time like a 195 switch I originally tried.

quote Originally posted by branger: if I just sit with it running in the driveway, will the fan automatically turn on?

yes, and your gauge may be well into the red.