Been noticing a lot of overheating threads lately. My car was doing the same thing and I pinpointed the problem the other day. To make a long story short, I had my 94 Bird and bought the 94 Z and did a drivetrain swap. The Z had a blown head gasket so I parted a lot of it out. I reused that radiator in the swap and car had been overheating like mad. I have had the problem since the first of the year but hadn't done much driving so it didn't really matter. The last couple weeks I started chasing it down. I put on a new water pump, checked the stat and even put new hoses on--stuff I wanted to do anyway but didn't help with problem. Air was bled no question but still had the problem. I decided the radiator was the next thing to turn to. I started putting it all together and realized the radiator was the common link between my overheating engine and the engine with a blown head gasket. I went to my spare parts pile and dug out the radiator from the other car that I knew was good. I swapped them out, filled and bled, now car barely moves off the 160 mark on the gauge. Check your radiators folks! I noticed on the blown engine that there were some serious calcium deposits on the water pump. Looks like previous morons didn't use coolant. I am 100% sure that is what the inside of that radiator looks like. Hindsight is always 20/20, just wish I had made the connection before. But all's good now!

 

yep, they dont last forever.

 

My overheating problem is due to the PCM only seeing 180 deg when its boiling over, so it never kicks the fans on. I wired a manual switch in, and its fine now.

Sara Lou

 

Is this due to a malfunctioning water (pump) temp sensor? I noticed on the car I bought that the sensor was also broke and they had cut up the wiring harness for manual fans. I am assuming after they broke it that the fans quit working. I had a good sensor, rewired the harness and fans work fine.

 

actually i had a question.. just put my slp fanswitch in with stock stat and on low fan it ran about 175 ish i just put in my hypertech 160 this morning and its running hotter like 195 with high fans on i also already bled the system 4 times no air and i know my rad is good thinking about putting old stat back in sorry

 

I replaced the sensor in the W/P, but it made no difference. I'm leaning toward the PCM as now it won't communicate with any scanning software anymore either.

I have another PCM sat here waiting to be reprogrammed (it came out of a "B" car), once I get that installed i'm hoping it fixes the prob, if not, then i'll start tracing it down.
Under normal driving it holds steady and cool, just whenever I hit traffic or sit idling it starts overheating, but the manual switch has cured that too now.

Sara Lou

 

When I ride my car at stop and go traffic.. It always go to 210.. But when I rde at 120 or higher speeds at highway it goes down 160 or a bit less..
Is that normal?

 

Stock tune I presume?

 

You guys must check to see if your fans are turning on, I had a secondary fan go out on my LT1, I started noticing that the temperature gauge was getting up to half way... before it wouldn't even go above 180 because of the PCM tunning. I tried to run fans directly and AC fan was burnt it didn't even turn a little. These fans automatically turn off on the highway, and car cools down from fresh air it gets while running, got to have the spoiler that is there at the chin....