Hello everyone. New to the site. I have a problem that I would like some help with if possible. I have a 1986 IROC Z28, tuned port injection 305. My problem is that the gauge shows that it is overheating. So I had it checked out by a mechanic. He put the vehicle on a scan tool and ran the vehicle for a while. the fan will turn on at about 220-230. And shut off when necessary. Inside the dashboard to gauge what show 260 before the fan Will Go On. I ordered a new gauge and replaced it this morning. The Gage still does the same thing. Both switches have been replaced. Meaning the one on the driver side head, and the one on the intake manifold under the throttle body. he said it was not necessary to replace the one by the passenger side head because the fan was working. Not sure where to go at this point. Any help or advice would be greatly appreciated. Thank you.

 

Sounds to me like either a short in the wiring, or you used the wrong sensor in the driver side head. I did that before and it pegged the temp gauge. Double check and make sure you used the right sensor for the car

 

Thank you for the information. The gauge was doing the same thing before I changed the sensor on the driver side head. So I think I'm going to look at the wiring to see what the problem is. Thanks again for your reply. I certainly appreciate it

 

No problem at all! If it's like mine it's just 1 wire going to the gauge, shouldnt be hard to find a short if it's there.