overheating prob

product1620 · Post by **product1620** » Thu Dec 07, 2006 4:56 pm

hokay, my fiero will run hot unless I play with the heater/ac. The rad fan will not come on automatically, I have to use the ac, but sometimes when its idleing even with the ac on, it still heats up untill I rev it a few times, and then it will drop back down to the normal temp. Thoughts???

Series8217 · Post by **Series8217** » Thu Dec 07, 2006 5:38 pm

What year/motor?

product1620 · Post by **product1620** » Thu Dec 07, 2006 5:49 pm

87 GT 2.hate

Fastback86 · Post by **Fastback86** » Thu Dec 07, 2006 6:45 pm

You sure your temp guage isn't being retarded? Barring that, I'd say your thermostat or water pump (or both) are going.

Series8217 · Post by **Series8217** » Thu Dec 07, 2006 7:49 pm

Check your fan switch wiring. If the wiring is good replace the switch. The fan should be coming on automatically.

The overheating until you rev it sounds like a sticking thermostat or an air bubble. Is there coolant in your overflow tank?

product1620 · Post by **product1620** » Thu Dec 07, 2006 8:51 pm

Series8217 wrote:Check your fan switch wiring. If the wiring is good replace the switch. The fan should be coming on automatically.

The overheating until you rev it sounds like a sticking thermostat or an air bubble. Is there coolant in your overflow tank?

Well, the thermostat is brand new, and I tested it before I installed it. If there is a buble in the system, could that be causeing the fan temp switch to not be reading the temp? I'd say the buble is a good posibility, because I just replaced the rad in the car, and maybe I was a dumb ass and did not do the proper refilling procedure? I'll try and head up to the shop tomowrow, to check the overflow tank, but I'm pretty sure it does have coolant in it.

The Dark Side of Will · Thu Dec 07, 2006 9:28 pm

Fill procedure: take off front and rear caps & remove thermostat. Fill at rear location until coolant level comes up to front fill hole. Replace front fill cap and continue filling until system is full at rear, then replace thermostat and rear cap. Fill overflow tank to appropriate level.

Fastback86 · Post by **Fastback86** » Fri Dec 08, 2006 1:40 am

The fan switch is on the top of the engine, which is the highest point in the system, which is where your air bubble is going to be, so conceivably that could be causing your fan switch problem if the bubble is big enough.

Also, after you fill your system using Will's procedure, put the thermostat cap back on and run the engine for a few minutes, then check again. Its gonna be hot, so be careful, but running the engine will cough any remaining air in the system up to the top again (the thermostat). May want to do it more than once to make sure its all out.

Pyrthian · Post by **Pyrthian** » Fri Dec 08, 2006 8:55 am

1st - you need to get yer fan working. hit it with 12v to see if it even turns. if it does
2nd - check fan switch - I think its a "ground switch" - as in, when it closes - it closes the path to ground. so, to check, use ohmmeter, on end in the switch, the other end on ground. when temp is reached (normally, about 1/2 way on gauage) - the ohm should go from infinite/real big to zero/real small. a dial ohmmeter is better for this - you can see the needle swing. if it does
3rd - well, your fan works on 12v, and the switch works at temp - this means the wiring is bad - most likely its is the connector. its partly exposed to the elements, and corrodes easily - clean it or replace it. replaceing with a nice wheatherpack connector is a good thing

note: step 2 assumes the fan switch is a ground switch. I dont know this for a fact. but, being a 1 wire switch, I cant think what else it maybe...

product1620 · Post by **product1620** » Sun Dec 10, 2006 5:36 pm

anyone know the coolant capacity for this car???

Jinxmutt · Post by **Jinxmutt** » Sun Dec 10, 2006 5:54 pm

Pyr has the right idea on the fan switch. If you pull the connector and with key ON (eng need not be running) short it to ground. If you the front lid open, you'll be able to tell easily if the fan kicks on. if it does, the switch is your problem.

product1620 · Post by **product1620** » Sun Dec 10, 2006 7:32 pm

product1620 wrote:anyone know the coolant capacity for this car???

bump

Shaun41178(2) · Post by **Shaun41178(2)** » Sun Dec 10, 2006 7:51 pm

13.9 qts. which is like what, over 3 gallons?

product1620 · Post by **product1620** » Sun Dec 10, 2006 7:53 pm

Thanks dude :thumbleft: