Over heating!!!!!! [Archive] - GrandAmGT.com Forum

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bouji1
06-15-2009, 09:18 PM
ok so my 99 gagt is overheating but only when i'm sitting still. i thought it was from the fans not kicking on but i changed the engine coolant temp sensor and its still doing it gets to about 4 or 5 bars over 200. usually i just go very fast so that it gets plenty of air and it cools down in a couple of minutes. any suggestions because this sucks

SuburbGT
06-15-2009, 10:02 PM
check coolant level?
check for leaky gaskets?
check or replace thermostat?

and if your driving and it's overheating, you could always turn the heat on to try to cool it down

sbart385
06-15-2009, 10:07 PM
Sounds normal. Fans dont kick in till like 235* or unless the A/C is on usually. Changing the coolant temp sensor doesnt change the temps that the PCM is programed to kick on the fans.

bouji1
06-15-2009, 10:40 PM
Sounds normal. Fans dont kick in till like 235* or unless the A/C is on usually. Changing the coolant temp sensor doesnt change the temps that the PCM is programed to kick on the fans.

no man thers 2 speeds on the fans. the low speed are supposed to kick on at like 219 or something like that. and coolant level is good. it doesnt over heat when drinig only when i sit with my car idling for like 10 mins.

AaronGTR
06-16-2009, 01:03 PM
Temps for coolant fans. :)

http://www.grandamgt.com/forum/showpost.php?p=1032729&postcount=17

sbart385
06-16-2009, 04:12 PM
My bad i was off by a few degrees. Still... it has to get up to 223 before the low fans even kick on

2000 GT Coupe
06-16-2009, 09:57 PM
thermostat is a likely option.

burgett2103
06-16-2009, 10:26 PM
its common to overheat while sitting still and idling. Mine goes up to about 225 at times but when i start drivin it goes back down.. i don't think it's much of an issue

AaronGTR
06-17-2009, 12:34 PM
225 or even 230 is not overheating people. Once you start getting into the 240-260 range, then you should start to worry.

350rs
06-23-2009, 11:17 AM
WOW! why do these things run so hot? Mines generally right around 200 degrees ( according to the dash) Even sitting. Its around 100 right now here and even still. Do they have poor air flow or is this just what they are designed to run at? Mine ran around 3 bars past, not sure what the increments are so ill let yall decide, i did a flush and a thermostat change since i had no idea how old this stuff was and with the LIM leak, i wanted fresh. Since then its never been over 200ish.

sry to jack the thread btw..

AaronGTR
06-23-2009, 03:50 PM
Yes, they are designed to run that hot for emissions and fuel mileage purposes.

bouji1
06-23-2009, 04:17 PM
Yes, they are designed to run that hot for emissions and fuel mileage purposes.

yes but i sat once in traffic and it was so hot that smoke was comming out of the overflow on my reserve antifreeze tank. it never did this before. shoul i replace the thermostat? and if so with what kind.

BTW THANKS FOR ALL THE HELP GUYS!!!!!!!!!!!

and also i have subs so i keep my car running when i'm parked so i dont kill my battery and the temp keeps rising untill i turn it off. it doesnt just get hot and stop. it gets hot and keeps getting hotter. it used to run at 1-3 bars over 200. it has 78000 on it

AaronGTR
06-23-2009, 04:33 PM
Check the level? Check for leaks anywhere? If the coolant gets low from say a bad LIM gasket or a leak else where, it will get air in the system. If that happens it changes the boiling point of the coolant because of the pressure differential... meaning if the coolant has room to expand, it will boil at a lower temp. If that happens it will exceed the pressure of the cap and it will vent steam. Sometimes that happens also if the cap on the pressure tank is bad. Have you replaced that yet?

The only other things that typically make them continue to get hot and overheat are a plugged radiator or blown head gasket. Really with either one of those you should notice it overheating even if the car is moving. Especially if it was a blown head gasket you'd notice it overheating immediately if you ran the car at all.

bouji1
06-26-2009, 12:03 AM
Check the level? Check for leaks anywhere? If the coolant gets low from say a bad LIM gasket or a leak else where, it will get air in the system. If that happens it changes the boiling point of the coolant because of the pressure differential... meaning if the coolant has room to expand, it will boil at a lower temp. If that happens it will exceed the pressure of the cap and it will vent steam. Sometimes that happens also if the cap on the pressure tank is bad. Have you replaced that yet?

The only other things that typically make them continue to get hot and overheat are a plugged radiator or blown head gasket. Really with either one of those you should notice it overheating even if the car is moving. Especially if it was a blown head gasket you'd notice it overheating immediately if you ran the car at all.

ok well i dont think my lim is bad because i'v never noticed any leaking but not sure. my head gasket is fine. i never changed the reserve cap so maybe id try it.

westerndragon
06-26-2009, 07:27 AM
Mine does that also. When I took out the OE thermo it was gummed up from that freakin dex cool crap so I flushed the whole system again and replaced it with the good ole' green junk

I replaced the thermo with a 180* and i still at just under 200* my GM guy told me 3400 = hot.

FuriousG
06-26-2009, 10:08 AM
If it's been a long time since you've had the coolant changed that may help too. Old coolant isn't' going to work as good as some fresh stuff in there. May not be the problem you're having but it couldn't hurt.

ss88
06-28-2009, 01:35 PM
Does anyone (or GM) even have an explanation as to why the thermostats don't last in these 3400's? I kid you not, I have had FIVE different thermostats in my vehicle over 2yrs and 30K miles. The last one I bought was a "fail-safe" thermostat, which toke a little while to become fail-safe; i.e. I was overheating for about a week. Now, its stuck open and I havn't gone over 210 in summer time.

So, my advice to anybody with overheating problems: trying removing your thermostat first!

AaronGTR
06-30-2009, 09:50 AM
Does anyone (or GM) even have an explanation as to why the thermostats don't last in these 3400's? I kid you not, I have had FIVE different thermostats in my vehicle over 2yrs and 30K miles. The last one I bought was a "fail-safe" thermostat, which toke a little while to become fail-safe; i.e. I was overheating for about a week. Now, its stuck open and I havn't gone over 210 in summer time.

So, my advice to anybody with overheating problems: trying removing your thermostat first!

Thats not such a good idea either. The thermostat is there for a reason and if you live in a cold climate the car will not run well in the winter. It would run extremely rich because the coolant would never get warm. You'd end up fouling your O2 sensors and probably burning up your cat, and you'd have no heat inside the car.

Thermostats are pretty universal parts and a lot of cars use the same one as the GA, so it's not our specific T-stat and it's not the cars fault. They do go bad eventually so thats normal, but having them fail after a short time is not really a common problem. It's usually installer error. If you don't install it right or don't bleed the system properly, it won't work right.

ss88
06-30-2009, 05:49 PM
Aaron,
All of what you said, is true. And I do live in a cold climate, so I'm trying to figure out what to do before it gets cold. Maybe some good old fashioned cardboard in front of the radiator lol.

I don't know man, I've purged the air out every time and its almost impossible to install them backwards.
The time before the last install, I asked my neighbor, a mechanic to look at it and he purged the air out himself. I don't know whats up with it. He suggested replacing the water pump - - which is probably what I'll end up doing next.