I have an 86 IROC with 305 TPI. I recently had the engine replaced with a GM Factory crate 305. Since the engine replacement the temp gauge shows the car running hot. The shop has ran checks on the computer and sending unit and both are working properly. When the car is started the temp gauge rises rapidly and then if you tap the glass the gauge will come back down.

Anyone have any ideas on this one...........

Thanks

RLF

 

check this chart out.