I have an 89 IROC-Z with a 350TPI. Its bone stock. I never really drive the car unless its to a car show (even then I don't enter it ). Therefore I am selling it and it sucks that this is happening now. On the way to the car show, the car stayed nice and cool while moving. Well, I had to wire a manual switch inside the cab temporarily about a month ago for the cooling fan because they do not work (even after I replaced the switch, relay, and sensor). So far I have never had a problem with its cooling but then again I wasn't in traffic. Well anyway, I was on my way to the car show and the traffic was thick as always. So I turned on the switch for the fan. Even while sitting in traffic, the car began to heat up and almost hit the red until I pulled in a parking spot and shut it off. It came close but didn't touch it. The fan was on because I got out and looked. Well anyway, I ordered the PAINLESS Independent Fan Switch ($80 Kit) from JEGS and have not yet installed it. BUT the fans were on anyway (I just bought it to get rid of that manual switch). Therefore I ask, does anyone know whats wrong with my car?

Stuff I noticed:
Coolant is topped off
Radiator cap is new
Thermostat is new
Fans were on
No leaks ANYWHERE
Airgrabber thing on bottom of the bumper is still there




Please help me someone. I would hate for someone to come and buy this car and try to drive it home with this problem.

 

Is the water flowing after car reaches temp???
if not i would say temostat is bad or wrong temp for your car it should be a 195 deg unless you get chip you could go lower.

Have you ever flushed out the radiator?
that will cause over heating problems.


My car did the same thing and i replaced themostat and that fixed it.

good luck

 

By far, the best description for the air dam ever.

Saying you replaced all the various componants, that just leaves really the integrity of the cooling system to guess. What does the coolant look like? Drain a little bit out of the bottom of the radiator (top it off with some water) and see. make sure there's no murkyness to it or anything of the sort.

Another thing, make sure there is sufficient air flow over the radiator. Nothing blocking it like leaves, bugs, etc.

 

Does the car still have the original radiator? The same thing used to happen to my 88 Camaro for several years. Driving down the freeway was fine but once I got into stop n go traffic the coolant temp would shoot right up. To keep it from boiling over I would have to roll my windows down and turn the heater on full blast even in the south Texas heat. LOL. Then one day I decided to fix the problem. I took it my local radiator shop and they told me that my car was originally equipped with a plastic radiator designed to last about 50K to 60K miles, then get tossed and replaced. Well, I opted for a metal 3 core radiator and the car hasn't come close to overheating since even in stop n go traffic in the south Texas heat. Sorry for the long post. It's only my second one.

Gene

 

Repzard: I am pretty sure it is flowing fine. I don't think the hose is collapsing. Every time it has ever ran hot, when I pop the hood, the hose is fine. I have flushed the radiator. Actually that was the first thing I did when it got hot aside of the thermostat.

Stekman: Thanks. I worked on that for a while. The coolant is fine. Clean N Green. As for the flow, for what little bit a thirdgen gets, its fine. I checked for leaves in the openings, between the radiator and condensor, and any blockages anywhere else. All clear.

galvarado: Thanks for the advice I'm beginning to think that that's maybe what it needs. Like I said before, I'm not going to sell this car and let it overheat on someone on the way home. Whats the cheapest yet good metal radiator you guys can think of?

 

The radiator shop I took the car to got it for me so I can't help you on that one but I've heard people get them from any auto parts store. And I've seen them brand new on ebay as well. I know that when I compared the old radiator to the new one I noticed the difference right away(plastic/composite as opposed to metal). And the new one was a 3 row as opposed to my original 2 row. That was my experience with it and haven't had anymore problems since I replaced the radiator 4 years ago. Hope all the info you've received so far helps solve your problem.

 

I'll be checking tomorrow for a metal radiator

 

I sort of have that problem too, i have a 89 RS with a L03 engine in is (that is the one out of the trucks isnt it?) and when I build the engine and put it in everything was new; water pump, themostat, coolant, hoses, and the radiator was dipped and cleaned and new plastic sides put on, and I had to get a autometer temp gauge, and the when im going down the road the temp stays at about 180 or a little bit higher, but when im sitting still or in traffic it goes to about 220 or so and thats when the fans kick on somewhere around there, and the fans cool it down a little, before they shut off, is this the normal cycle for the temp ranges in these cars, like I said everything was new about 4000 miles ago, thanks alot for any help!