Does the temp gauge on the dash register the block temp or the coolant temp?

 

Coolant temp

 

Thank you, Tuned Performance. I raised the question because I had experienced a gauge reading of about 230-240 in some stop and go traffic and I began holding a high idle and turning on the heater full hot. That plus some traffic movement got the gauge back to about 200.


When I took it to a local, trusted shop, they replaced the secondary fan switch and told me not to expect it to turn the fan on until the engine reached 236. Except for one other failure (the fuseable link to the fans) a few years ago, the gauge always stayed at a steady 195-205 degrees. I am the original owner and religiously monitor the temp gauge when operating the car. I am wondering what would cause it to now run hotter than it did for the first 27 years. Guess I'll need to just drive it around for a while in the hot Florida weather and see how it performs. Maybe the shop guy was just trying to show how smart he was or there was a lower temp switch installed when the car was new.

 

The secondary fan should turn on at 226f. You can install a grand national switch sw555 that turns on at 210f and off at 205f. Your gauge might be incorrect or you might need a new sender. A coolant flush might also be a good idea if it’s really running that hot.

 

The cheapest place to get a SW555 is from rock auto getting a fan switch for a 1989 Turbo Trans AM


https://www.rockauto.com/en/catalog/...an+switch,4312

https://www.rockauto.com/en/moreinfo...1571&jsn=10547

 

you can get a variety of switches that turn on at different temps I recently put one in that is set at 180 degrees.


https://www.summitracing.com/search/.../185-degrees-f