Hello, I'm new here to this forum and I was wondering if you guys have any suggestions on my cooling system. I have a 1986 Pontiac Trans Am, with tune port injection and it's been having a ton over heating problems. The problem is at regular driving speeds the car temperature goes up past 220 if I let it. When you stop at red lights or when idling, it stays at 200.

I've replace the thermostat which is 185 temp, I've fixed my broken air dam, I've replace the water pump, I've replaced the radiator with a slightly bigger one, and I have a cooling fan running on a toggle switch since it has wiring issues.

Is there any advice or help that can point me in the right direction? Any really would be appreciated since I've been struggling to pin point this issue for awhile.

 

Have you verified the engine temperature with a infrared thermometer? The gauges on these cars can get wonky with age.

 

6 months to a year when I was 1st starting to dive into it, it used to hit 220, it would completely boil over. I'll have to try out the infrared out, thanks.

 

Did you replace the radiator cap when you installed a new radiator?

 

Yes.

 

Another suggestion is get that wiring sorted for the fans and get a custom tune to lower the fan temps. Getting the fan temps lowered will really help the car out, made a big difference in mine.

 

I'll have to look into that as well. Also, do you have any idea where I can get a wiring harness for the motor and the intermidiate for the dash as well? Thanks once again.

 

eBay is always a good place to start, I’ve used Jason Fritz at Fbody graveyard for parts before and Firebirddude on here always seems to have lots of stuff. Camaro heaven in tilton NH also has a nice catalog of parts and they specialize in third gens. Hawks is also an option but it will not be cheap...good luck and keep us posted.

 

Thank you once again and I'll keep you posted. Take care.

 

Simple question, did you BURP this radiator? I had issues similar with my minivan and I burped it and its fine now. Also, I read a 170 thermostat is optimum for the Thirdgen V8s, which I will do next spring. Make sure you sensors are good, I just replaced the one for the cooling fans on my car and that got them going again.

 

^^^^THIS is the first place to start troubleshooting.

The temp gauge on 3rd gens provides little more than a suggestion rather than any accurate information.