I have a 2003 GMC Sonoma & when i try to run the air conditioning it runs too
- Thread starter Ddille
- Start date
Molson02536
New member
Common for the engine to run a bit hotter when the Sonoma is not moving cause of the A/C condenser at the front of the radiator. If your coolant has never been serviced, it's most likely your coolant will need to be flushed out. The Dex-Cool coolant the GM uses in there vehicle is only good for up to 5 years or 150,000 miles which ever comes first.
There are many people that complain about Dex-cool antifreeze, but as most they don't keep up on the regular maintenance. Dex-cool left alone and not serviced will crystallize causing issues like what you are experiencing due to bad coolant flow through your radiator, heater core and throughout your engine's water jacket.
Flush out your coolant with Preston coolant flush as per GM TSB, replace the thermostat and refill coolant with 50/50 mix of Dex-cool antifreeze. To much water and your coolant will boil over and to much Dex-cool will make your coolant jell causing flow restriction again. Most will often go back to the green coolant, but that is only good for one year or 30,000 miles then you have to flush out the system again and refill.
I know most will not do that or only add water in to there overflow canister and say they don't have any issues, that's good but than again it's there car and i am not about to chance me on the side of the road on one of the hottest days in the summer. That is fine for driving around the city without long period of time, it's like going to the drag strip and your forced to run just straight water in your cooling system. Short duration engine running time and any evaporated water will just need to be toped off every run.
Good luck and don't forget to replace your thermostat also, servicing the cooling system also consist of replacing the thermostat. Good luck and be safe.
