I have a very hot-natured 89 IROC with a TPI 305. Both fans run fine, the thermostat has been replaced, the water pump works,no leaks are present, and all sensors have been also been replaced. The car continuously runs hot and even overheats. The fans used to not work but after replacing the fan control sensor in the passenger side of the block they work fine. However, the car runs just as hot now as when the fans did not pull any air through the radiator at all. What is a typical operatin temp for this car? The lowest it typically sees is around 230 degrees. I am completely stumped as to what else can repaired/replaced other than the radiator itself. I am going to replace the gauge with an aftermatket one with a little more detail than the stock temp gauge and see it is just misreading the temperature. Any help you can give would be greatly appreciated.

 

do you have an air dam? have you flushed the system

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1992 Camaro RS LO3/700R4
Brand New 3" Exhaust I-Pipe For Sale
Slightly Used Flowmaster 80 Series Muffler With Tailpipes and Tips For Sale
Brand New ZZ4 Roller Cam For Sale

 

If you do have an air dam in place, it is likely your radiator. Don't bother having it rodded out, The $50-$75 it will cost will just be a temporary fix at best. Just buy a new radiator, preferably one with four rows of tubes. I think somebody on eBay sells them for $108.

 

Also check between the ac condensor and the radiator. You will be amazed as to the amount of leaves and crud that will collect there.

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Mike

'90 IROC-Z, 5-speed, ZZ4, G1 Trick Flows
Moderator SEThirdgen

 

Let's find out if your radiator is getting air, do you have air conditioning? Is the air conditioner radiator, all smashed up and the fins are bent over? Is there stuff between the air conditioning radiator and the coolant radiator? I took everything out for my rebuild and found leaves and some kind of nest in between the two. I bought my car last summer drove down to Tulsa, Ok and drove it back on the second day of the trip it was quite hot and she started getting to 220 which was too hot for me. I pulled over drained out about a gallon and put water wetter in and some new coolant and then I took out the fog lights, Is your air dam under the radiator in place? That helps alot!!! if none of this works, get a griffin or a be cool radiator, watch ebay I got out bidded on one for 198.00 There out there and ppl need money, so look for em.. Hope some of those tips help..

Kevin

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86 Chevrolet Camaro Iroc Z-28 Fully Loaded With T-Tops
Mods;
Spohn SubFrame Connectors, S&W Race Car Chassis 8 point Roll Cage, 1997 SS Aniversary 3.42 POSI Rear End with 12" Rotors and 4 Piston PBR Calipers, Balanced Drive shaft... Others soon to come...

Best times before any mods done, Complety Stock;15.6 @ 87mph
Waiting for the tracks to open again to see what I got going on Now!

ntimad8.cz28.com

 

The normal factory operating temperature was somewhere around 230*

What I did to combat this was pull the plug from the passenger side cylinder head and grounded it to the car's body/frame. That right there will kick on the 2nd fan whenever the key is in the ignition. I guarantee you see a 50* drop in temperatures considering you have a good water pump and radiator. That is my little experience.

Good Luck.

 

I can feel your pain. Well it sounds like you've done your best to fix this problem, but no one even thought about having air pockets in the coolant system. That alone can wreck havoc on your coolant system. How to fix that's if all the coolant parts of system are in good working condition.
1. Let the car cool down and unscrew the radiator fill cap.
2. Have some coolant avalible, start the car , turn the heater on at full blast and wait until the your thermastat opens, so when it does the coolant in the system circulates through the entire system to relieve it of the air pockets.
3. Ones you've gotten all the air out of the system put the radiator cap back on.

Sometimes that helps, but f- bodies are notorious for overheating. Goodluck!

 

The 230 is the max temp the car will reach at idle which is way too high. I believe that the air dam might be missing I will check on that. Would putting in a 180 thermostat help? I have been told this would interfere with the Powertrain Control Module. I dont see why though. Also, the radiator appears to be fine externally, there is no crap stuck in the fins and none of them are bent/crushed. Im gonna flush the radiator and see if that helps, along with replacing the air dam. Thanks for the help Ill let you know how it goes.

 

I've been thinking about this lately also...If EVERYTHING works good, including the fan(s), thermostat, radiator, airdamn...Is it possible that someone MIGHT have the wrong water pump on a thirdgen. Like if they have one that turns the wrong way? If he bought the car and it had already been replaced beforehand...it's possible, right?

My last car always had fan problems and it definately sucks. goodluck man

My 89 305 TPI finally runs cool. 220 in traffif and 180 on the freeway

Denny

 

Denny, I won't even tell you what mine runs in traffic and on the highway. Its way lower than that.

 

try a 160 thermostat and do what lounge lizard said alot of crap can build up in there.Also while your at it put in a manual fan swithch.