Cooling Issues on 94 Z28
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Teching In
Joined: Nov 2001
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From: Elburn, IL-The land of Corn and Fast LT1's
Cooling Issues on 94 Z28 We have a cooling issue on my brothers 94 Z28 with 193,000 miles...
The car consistently runs at 210-225 and you have to keep the defroster on to make the fans stay on. If you are at a stop with the defroster off the fans will go off and the temp will go all the way to the red. Also, sometimes the fans will come on even from a cold start...seems like sometimes they run all the time and other times when you need them they don't do anything. Reguardless of what the fans do the car goes up to 210-225 every time. The car heating up this much caused the radiator to crack a week and a half ago!!!
Things that have been replaced in the last 6 months to correct this issue:
160* Thermostat - twice
Water Pump
Radiator (today)
Car runs and drives fine and still makes great power. No normal signs of bad head gasket (coolant in oil, coolant leaking from heads, etc). It has been doing this since last summer and everything we have tried so far has not worked.
I hoped that it was just a bad radiator and replacing it today would fix the problem, but it did nothing...
So where do I go from here?
Let me know what you got.
Thanks,
Eric
The car consistently runs at 210-225 and you have to keep the defroster on to make the fans stay on. If you are at a stop with the defroster off the fans will go off and the temp will go all the way to the red. Also, sometimes the fans will come on even from a cold start...seems like sometimes they run all the time and other times when you need them they don't do anything. Reguardless of what the fans do the car goes up to 210-225 every time. The car heating up this much caused the radiator to crack a week and a half ago!!!
Things that have been replaced in the last 6 months to correct this issue:
160* Thermostat - twice
Water Pump
Radiator (today)
Car runs and drives fine and still makes great power. No normal signs of bad head gasket (coolant in oil, coolant leaking from heads, etc). It has been doing this since last summer and everything we have tried so far has not worked.
I hoped that it was just a bad radiator and replacing it today would fix the problem, but it did nothing...
So where do I go from here?
Let me know what you got.
Thanks,
Eric
Last edited by Spray'n LT1; Jun 30, 2005 at 05:58 PM.
Thread Starter
Teching In
Joined: Nov 2001
Posts: 28
Likes: 0
From: Elburn, IL-The land of Corn and Fast LT1's
Originally Posted by Donohue96M6Z28
maybe its a bad temp sensor
Solved my own problem...
I hooked up a Scanmaster to the car which reads off the PCM...the PCM reads 218-226, which is because...apparently the car has a 160 stat in it, but it does not have a tune for the 160 stat...no big deal...but when my PCM is seeing 218-226 my gauge is seeing 245-260...
So apparently one of my temp sensors is screwed up.
Either...
The sensor going to the PCM is wrong causing the fans not to come on until the coolant is 260 degrees
Or...
The sensor going to the dash is wrong and the car is cooling just fine.
I am going to lean mroe toward number 2 since the car does not show any other signs of overheating.
So I will replace 1 or both coolant temp sensors and make sure the car gets tuned so the fans come on for the 160 stat.
Thanks guys,
Eric
