Different overheating problem??

Have an '03 Impala LS with the 3.8 and 91k miles. Termp gauge tends to climb about 20 degrees when in slow traffic or driving in town and has the smell of warm coolant. The ever dreadful intake gaskets were changed by a dealer 6 months ago. The coolant level is not low and have never seen any coolant leaking. Changed the thermostat one month ago and thought that fixed it, but problem is back. Low coolant light has never come on. This happens whether running a/c or not. The other day we were in stop and go traffic with the a/c on and i noticed the temp gauge up again. I opened the drivers window and i could feel heat "blowing" from the engine area on my hand. Once back to highway speed, the temp went back down to normal. Any ideas??

have you checked to make sure fans are coming on??

I am checking into that next. As it is my wifes car, not had a chance to dirve it again. Will update when i investigate this. Thanks.

I am checking into that next. As it is my wifes car, not had a chance to dirve it again. Will update when i investigate this. Thanks.


ya check the electric fans that is a good idea when you have these componets to cool the radiator.....then make sure you have pressure in the system no pressure and you will overheat...

bad cap , leaks, and the head gasket as well as other items that cause a loss of pressure..


remember a water pump can only pump water not air bubbles...

Drove car yesterday, fans are working when they are supposed to. Still is running hot when idling or moving slowly. I checked the radiator and it had some very minor sludge on the cap. Could the car just need a good radiator flushing and new coolant? I have not touched it yet since GM says the coolant should go 100k miles.

Drove car yesterday, fans are working when they are supposed to. Still is running hot when idling or moving slowly. I checked the radiator and it had some very minor sludge on the cap. Could the car just need a good radiator flushing and new coolant? I have not touched it yet since GM says the coolant should go 100k miles.



drain as much coolant as possible ..then disconnect radiator hoses and flush out the radiator....capture all in a bucket to check for debris and look into radiator for cooling tube blockages........your system takes about 3.25 gallons of coolant you may get 1.5gallons out so make sure you put 1gallon of dexcool to 1/2 gallon of water... this will keep things protected.. if this improves your hot running repeat all this again and this will get you to a point where the coolant should last another 3years.... I never go more than 3 years on dexcool...and never use non dexcool or your in trouble...

Thanks j cat, i will try that next. Will reply when i get it done to let you know the outcome.

Had a reputable service guy flush coolant last week as it only cost $70 and i did not have the time. He said it was very dirty. Still smells slightly of coolant, but that could still be from spilled coolant. Temperature range appears to be back to normal.

good to hear but keep a close eye on it for awhile

Will do.

Well, strike #2. Car is still running a little warm and has slight smell of coolant after it engine gets hot. No drips and no loss of coolant. Not sure what to look for now, may have to take it to a service guy.

Well, strike #2. Car is still running a little warm and has slight smell of coolant after it engine gets hot. No drips and no loss of coolant. Not sure what to look for now, may have to take it to a service guy.

you stated that when you replaced the thermostat it was ok for a while...was this oem type or some other brand....care must be taken when replacing some parts thermostats must be OEM on some engines...replace thermostat...again...

your thermostat is not responding to the temperature variations of the coolant...usually bad/cheap thermostats will act this way...many years ago when I was stupid I used to use cheap thermostats....it took 3 thermostats before I got heat out of my heater.. 1973 impala back in 1976....

you say its running a little hot. what is the temp gauge reading??

Sorry for the delay in my response. It normally runs less than halfway (cannot remember the exact temp at this time). It occasionally runs just past halfway and when it does that, you can smell coolant.

j cAT, it was not a real expensive thermostat, that much i can remember. You may be right that a better thermostat could do the trick.

j cAT, it was not a real expensive thermostat, that much i can remember. You may be right that a better thermostat could do the trick.


with todays engine management it is very important to use the correct thermostat and operate at the spec. temperature...If not you risk damaging your ride...buy a thermostat of a high quality usually a guaranteed type or OEM...I todays parts market I have seen very poor quality...in all areas..


don't forget that testing before install will save some pain...

I will try that next, thanks!!