I recently just bought an IROC and it is such a beatiful nice running car, but ive noticed a couple of things. I was only doing freeway driving at high speed about 65-75 the whole time and a little on the surface streets, and i noticed when i stoped the car had overheated pretty bad and alot of the water had boiled over. Well anyway the car has new fans and a new radiator so the first thing i looked for is the Thermostat, and there wasnt one, so i figured it must not be that because the vaulve would be stuck open, so the next thing i looked for is to see if the water pump worked and that seemed to be running fine, so now i am stumped and need some advice, also one last thing is that i know that my car uses no fans above 35 mph but the fans turn on periodically and also the temp gauge seems to only work when it wants to and usually doesnt at all.

Sorry about writing so much but any and all feedback is very appreciated, thanks guys.

 

i don't understand why. but camaro temp guages seem to always stop working. I have three friends with Camaros, and none of their temp guages work. and it seems that most people here on the boards with temp guage problems have Camaros. Now im not trying to say that there is anything bad about them. Cause i love camaros almost as much as trans am.. Just maybe a design flaw in the guages or wiring??

but on to the more important things.. you say there is no thermostat? if there is no thermostat then u definatley need one. it will slow down the flow of coolant and give it more time to be in the engine\radiator.. you might also wanna flush out ur coolant and add a mixture of about 80 water 20 coolant.. and u say ur car overheats all the time of just at low speeds? u might wanna get out and check ur fans to see if they are both running when ur coolant is boiling.. oh and replace ur radiator cap. just to make sure

 

There do seem to be a lot of worn out radiator caps out there. The engine coolant can get to 158 F without boiling with a 14 psi radiator cap. How come I am so smart all of a sudden about this, I just got an GMC service manual and it says so in there.
If you want Father Christmas to give you something priceless, you have to get one of the proper manuals. I got mine with discount for $63 from a dealership.

 

First off the fans are mostly not on no matter what speed im going or even if im just sitting there idling, the Temp gauge seems to work sometimes and not others, nothing came out of the radiator, it just was coming out of the water resivour, thanks..

 

That seems like alot of water, isn't the standard 50/50 mix. Does this help cool it off better, doesn't it lower the boling point substantially.

 

Yes, when the radiator cap fails, the water is seen boiling from the header tank not from the cap. The cap pressure control relieves to the tank, and allows coolant to be sucked back when needed. When the cap fails you get the symptoms you describe.

 

Buy a new water temp. sender/sensor, old one could be bad. Buy a therostat and new radiator cap. Check timing.

 

it really depends on where u live. i run 100% water. with redline water wetter. and it worked fine for me all summer long. but ill probably put about 20% coolant for the winter since it usualy never gets below 40 here in tx...

but as i said, it really depends on where u live. and if u use a\c then u want atleast 20% coolant to keep the heater core from freezing. (well this is what i ahve heard anyways...)

 

For info my temperature guage gave up too. I need to replace it, but I also have a second temperature guage and oil pressure, because I don't feel I can rely on the originals. In fact the original oil pressure gauge reads way higher than the mechanical guage.

 

This happened to me once before too... I was missing a lower air dam off the car. It deflects air up into the radiator, little black plastic flap goes on bottom of radiator... I was driving down the highway about at 120 mph or so... and once I got home I stopped and I had anti-freeze coming out of my refill tank.

Another thing is the fans have a computer kickon so they only run if AC is on, or it's above 220 or 225 temp or so.... which is way to high in my opinion I would look to make sure you air dam in on the car first, if it still happens wire up a manual switch there in tech articles... you can throw the switch once you hit say 200 degrees, kick both fans on, and cool it down to like 180 or so and then you flip it off and your fans turn back off.

 

Yeah the air damn is still on there, ill try replacing the radiator cap see what happens, thanks for all the feedback, hope something works.


Joey

 

Did you fix the overheating?

 

When my 1991 RS was overheating, I had it brought it to be looked at. I had the thermostat changed, but the problem was actually a fuse that controlled the electric fan. It simply would not activate it when it hit 220 degrees (needle straight up). Now that its fixed, when it goes to 220 (Im talkin drive throughs, idling), then the fan kicks in, and holds it around 220 which is safe. Before, it was in the red zone, and I was freakin out. Make sure its not somethin minor like that.

 

reading all of this is disturbing... Maybe I am one of the few technicians left, but there are a few things to check and ways to test parts without just replacing them. sending units can be tested for resistance, radiator caps and cooling systems can be pressure tested (autozone has the tools... they are free to use). Simple chemistry will tell anyone that 100% water, or 80% water is suicidal... "water wetter" does not adjust the boiling point, and 20% coolant will barely give you 220* protection. 50% is the recomended mixture for a good reason- is raises the boiling point and lowers the freezing point to points that are safe. If you want to destroy your engine, by all means run water, it keeps technicians like me in work, and you out ALOT of moey come time to make repairs.

 

You are close to Don. If you are still having a problem, go see him. He's busy, but give him a call or shoot him a pm.

 

as for running str8 water in your car that is bad for the fact of rust. i think the minimum tech standard is like 68%-32% either direction.the coolant helps with keeping your system unclogged too. as far as ur fans not coming on you may need a fan switch