An Overheating Problem

[Brute16]

Ok so I have a 1988 Pontiac fiero coupe. The 2.5 L and I have recently done the altenator belt, spark plug wires, plugs, Oil change, Oil filter, air filter, crankcase filter, egr valve and after all of this the car is running awesome, but now I have a problem. The car before never heated passed 220 on the temp guage but now it is going up to 230 and then it will go back down. Now I drive it and shift at about 3000 rpms with the occasional high shifts in there but Im thinking it may be the fan switch or the temp sensor or the fan motor or fan altogether. The cooling system may need to be flushed and yes I have turned on the AC to see if the fan works and it does but not very often it wont kick in at 220 like its supposed to so Im thinking of getting a new fan with better airflow to the radiator. But i wanted your guys' input before I start. Overall it shouldnt take over 100$ to replace the parts and all but I need my car to drive to and from work.

['88 Dread GT]

You may want to consider a low temp fan switch and thermostat. Hypertech makes a good fan switch (I have one in my '88 GT). They turnyour fan on at lower temps instead of waiting untill the engine reaches 224-235 degrees F like the stock switch.

The Hypertech swicth is $45 at Fierostore.com (you may want to check out Hypertech's website too and see if they're cheaper), and low temp thermostat is $10. RodneyDickman.com also has low temp switches for real cheap.

You definitley want to do a coolant flush every 2 years.

Hope that helps

=-Dread

[Brute16]

I thought they didnt have a fan switch for the 88 4 cylinders I thought the ecm told it when to turn the fan on. But yea I already ordered the thermostat and engine temp sensor since I need that too.

[13FIERO13]

I Have The Same Problum Lol
I Flushed The System And Made Mt Own Swich To Turn On And Off The Fan
It Works Fine

[1986fierogt]

you may need to buy a new radiator....cuz after i bought a new one and my fiero stopped over heating and thats all it need it

[Old Lar]

Fieros seem to overheat and I believe it is from poor maintenance of the cooling system, no flushes of the system. The radiator gets cruded up. The only time I have had over heating problems was when the fan motor died, the radiator cap was bad or the thermostat stuck closed. This was with my 88GT that I bought in 1996.

I have had my 87 GT for 20 years with no such problems.

[87fierochic]

I had that same problem also. but my dad had me run the heater or a/c all the time and it keeps the fan running as long as no passagers turn it off. my fan wont run unless i do this. I drive ALOT of gravel roads and when it gets turned off on accident my motor will smoke because its burning the crap off the motor. Thats only at 220. it freaked me out because all i had heard about fieros were that they caught fire. And its alil hard to see the smoke behind u when there dust clouds.

[Ragtop_Renegade]

The Fiero engine compartment fires were only known to occur on 1984 models. According to research done by both the highway commision and GM, the fires were caused by a combination of out of spec connecting rods and low oil levels. The underlubricated rods, already weaker then intended, would fail and punch a hole in the block. This caused oil to spray on the exhaust manifold and ignite.

The fan is controlled by the ECM, (excluding when the A/C is on, this overrides the ECM and runs the fan on a 100% duty cycle) which gets it's information from the coolant temperature sensor. A faulty CTS is easily identified when the engine runs unusually rich and fuel economy takes a sudden plunge.