My car was coming close to overheating during town driving, but would stay nice and cool on the highway. The fans worked, and I'm pretty sure my 180 t.stat works too. I tired to flush the system yesterday, and filled it with plain water, with the intention of adding the AF later (I'm changing the hoses, so it'll drain again soon anyway). This morning, on my 5 min drive to work, my car almost hit the red temp line. When I had to stop for some construction, the temp went back down. I never broke 35mph on the trip, and it was only 80ish outside. Could I have an air bubble, or doesn't the water cool enough by itself? Any ideas? I have a road trip in two days, so I would really like to fix this soon! Thanks.

 

I don't know if it's too late or not, but JUST water won't keep your engine cool. You gotta think, water boils at about 135.....the coolent in your car boils at a temp higher than water keeping the car cooler. BUT you also gotta remember....adding JUST coolent and not mixing it with water is just as bad as adding just water.

 

Ditto

 

You probably have a bubble. Water cools better than coolant. Oh, and water boils at 212 degrees--Not 135 Not to mention, that in a pressurized system the boil point is even higher. Some kind of additive is needed(like antifreeze) to prevent corrosion. Yes you don't want to run pure antifreeze. When the antifreeze is mixed with water it becomes coolant.

 

Yeah, what he said. 135?????????

Did you check your air deflector? From your description it sounds like thats your problem. Until you started doing things and got yourself an air pocket it sounded like maybe your air deflector was missing. Is your water pump circulating? Hoses not collapsing?

 

Ok, like I said, dumb question. The same day I posted this, my brain turned on, and I re-added A/F. It's just a hair under 50/50 (I needed 1.74 gallons, I had about 1.4), and it cools again. About an hour after I posted, I remembered that the A/F bottle also says "COOLANT". It still running hot in traffic, but at least not as hot with just water.


BTW, hoses are fine, pump works, air dam is there, fans turn on (although I can't tell when I'm driving )

Thanks for the kind responces - sometimes it's nice to not have anyone call you an idiot when you KNOW you deserve it!

 

IDIOT....Just kidding!!!


How hot does it run in traffic? Our cars are designed to run on the warm side as you are probably aware. Just about how hot do you think its getting, just curious.

 

viperwsu, my car is doing pretty much the exact same thing as your. On traffic it goes up to 240!!!!! On the open road it goes way down to like 160.

 

The proper workshop manual tells you that the car will overheat under the following combined conditions:
After driving and then stopping in traffic, with the A/C on and the automatic transmission in drive.
If you put the transmission in neutral or park, it can stop the car overheating.
This is probably because the cooling system was designed for a manual transmission. Also the torque convertor on the Camaro is quite tight, making for quick starts, but high engine load at rest.
If the car cools down when you start moving, it sounds like you need to try the neutral transmission trick.

 

When my car was all stock it used to do that and I knew everything was working properly. I think is just something you need to live with or start searching around to find the solutions to cool it off better. My quest for a cooler running car ended me up with a new radiator, fans, t stat, and fan control through the ECM. The tech article about fan control is pretty informative for those that want to turn the fans on earlier to help keep it cooler. Check it out.

BTW, before doing ANYTHING to help the car run cooler, double check everything to ensure it is operating correctly now...

 

Well, I would try that, but as you can't see from the sig that isn't there, I have a T56. I knew the A/C would warm things up too, but I haven't had it recharged yet, so I've been sweating it out with just the windows and vent fan.

I checked this weekend, and my fans are coming on, but the guage is almost in the red when they do. I there any way to test the coolant temp to see if I need to replace either the guage sender or the ECM's temp sensor?

I think it's getting to 240-250. The guage that came with our cars isn't consitant between markings (100->220->260 in the same arc), so I am guessing. It never seems to pass past the first red line, but then I never try to see if it will. When the needle gets that close, I turn on the heater to cool it off again. On the highway, it's around 160-180.

 

Your fans are not running correctly. If you are OK at highway speed then the cooling system components are fine. Coolant does very little for the boiling point of the coolant, straight water under 15 psi is about 250 degrees or simply add 3 degrees for every 1 lb of pressure above 212. If your symptom changed with the flush, then you probably do have air in the system and low water level. Simple check, engine cold rad cap off look at water level then rev the engine. If the level drops way down add the water to top off at about 1000 rpms. It takes about 100 miles of highway driving for the system to bleed itself. It takes about a week of driving to top off the cooling system at the recovery bottle. 50/50 mix of coolant either EG or Dexcool gives a boiling point at 15 psi of approx 265 degrees. Also, is the rad cap tight. If the system can't build pressure there may be the problem. If you do a system service don't forget a cap.

 

Wrong. Most TG's will run cooler in stop and go traffic with the A/C on. Reason, the A/C will run the primary all the time and A/C pressure kicks the aux fan on and off frequently. A clutch fan, maybe yes. Point of this, if the cooling system is operating correctly any GM vehicle will stay very close to normal operating temp under all but the most extreme conditions. A TG will run on average COOLER with the A/C on than off.

 

Like I said, the proper manual says, not me. It is under a section on how to deal with customers who complain about their car over heating. Anyway that's what is says.
Only trying to help.
NAPA sell a thermometer to put into the radiator to check the temperature, though it might be a bit risky on a Camaro system.

 

Andy, I was not trying to be a smart ***. You are correct in saying that if an overheating condition exists the owners manual and most books say shutting off the A/C can be a help, but thats only after the problem arises.

 

Well, I realized my fans aren't working all the time. When it reached 240 I checked and they worked... But at 220 they aren't comming on... I'm taking it to an auto electrician to see if they can figure out what is happening.

 

I hooked up my laptop to my aldl cable, and watched my ecm's data. For some reason, the guage in the car is reading a little high, but only about 10 degrees. What concerns me now is that the fans turned on (ecm requested) at 109.3C, and off at 102C. The PROM I burned is supposed to turn the fans on at 106C, and off at 104C. I just looked at my bin file, and that's what is set. Also, both fans are coming on at that time. Is this from the cyl head switch, and the ecm records it as a request? Any ideas on this one?