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Discussion Starter #1
Hi,

My car when it idles runs at the "M" and "A", then the fan kicks on and it drops back to "O" "R". I change the stat a month ago and everything was fine until I let the car sit for 3 weeks. Now when I drive it, it acts like I described.

I thought the fan was the problem, but I can hear it running and it only kicks on when the temp hits "M". I ran the EEC test and I can hear the low speed fan and the high speed fan test working (the fan spins).

Can the low speed fan work during the EEC test, but not when the car is running? I think I am only hearing the high speed fan.

What are the chances that the thermostat went bad after like 2 months?

Thanks,

Pete
 

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Is the upper radiator hose hot or cold when the car is overheating? If it's still pretty cold than the T stat is bad.

Might also be air in the system.
 

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Discussion Starter #3
the upper rad hose is very hot to the touch, you can't even touch it.
 

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Hi Pete,

first of all, don't put too much stock in the factory "NORMAL" guage. Most everyone agrees it is not a very accurate guage of temp. Second, yes your low speed fan could be not functioning. Third, a radiator is a heat exchanger. It really dosn't do the job unless air is moving across it, so if you are in traffic and the fan is not coming on, you are not really moving air. My 95, even with a Fluidyne in it, gets up to M-A before the fan kicks in. I had a chip in my 94 that kicked the high speed fan on at 185 and that sucker always ran N-O range except on the hottest days when the rad couldn't keep up. A lot of guys rig a manual switch to flip the fan on when they want to. This is a good fix until you get a chip or a tuner so you can manipulte the temp that the fan comes on. There are plans for the switch hookup here somewhere.

good luck
 

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Discussion Starter #6
Terry,

During the EEC KOEO test, the low speed fan does cycle on. Are you saying it is possible that it might not be on when I am driving the car????????? If so, how do I go about fixing it? Obviously the low speed relay and wire to the fan is good because it works with the key on engine off???????????????!!!!!!

Thanks,

Pete
 

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Pete

If the KOEO test cycles the low speed fan then it is probably okay. But again, even with my Fluidyne rad, my temp does not really start to go down in stop and go traffic till the high speed fan comes on. It just doesn't have enough air moving across it to exchange the heat. I think you really need to have the igh speed fan on sooner. I really wanted the fan to come on sooner in my 94 for 2 reasons. One just to keep engine temp down, but remember that heat is power. But my 94 was an AODE. ATF really doesn't like heat. I saw a graph once from an ATF manufacturer showing the inverse relationship of heat vs ATF longevity. ATF breaks down much faster once you get above about 180. It gets even worse the higher the temp goes. I figures since the ATF runs thgough a cooler in the rad, the lower the temps there, the more heat it could exchange. I also added an external cooler.

Have you ever had your rad cleaned out? When I removed the stock one in my 95, it had a lot of sediment in it that you really couldn't see. It looked good from the top, but when I ran water through it to flush it just out of curiosity, it was really full of brown gunk. At the age of our cars, a good professional flush, (or even replacement with a new stock unit if you don't want to put money into an eight year old rad) is not a bad idea.

good luck
 

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Did you make sure the radiatior is full? I know it sounds dumb, but mine started running warm lately, and it turned out the coolant was low. Added coolant and whola.:D My LOW COOLANT light didn't even come on!:mad:
 

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I know it is cold outside, but try this, turn on the AC to max, this will turn on the high speed fan and see if the temp goes down. Ice is not frozen to the radiator is it? If so could keep air from flowing through.
Just throwing things out to check.
 

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Discussion Starter #10
Hi,

Rad is full, and turning the AC on does help keep temps in check. What is baffling is that I dont see the low speed fan turn on, only the high speed. However, when I run the EEC test the low speed fan does work. I am ready to call it quits with this car.

Later,

Pete
 
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