Over heating
- Thread starter Spurling
- Start date
Bob Foster
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a/c puts load on your cooling system. But you may well have this problem
If it's an 03 or newer GM read below.
If you are running an 03 or up GM they have a weird coolant in them called Dexcool. The cores of these GM rads that have aluminum micro fins are prone to developing a gummy blockage that are hard almost impossible to properly flush out if they have been contaminated with regular coolant mixed with Dexcool.
Have you added regular coolant in to top the cooling system that wasn't Dexcool? If you mix regular coolant in with this stuff it coagulates and causes this awful goop that is hard to flush out of the system.
GM service trucks that spend a lot of time idling like utility trucks, telephone trucks and carpet cleaning trucks are prone to this gunk up. The cure is a radiator replacement. Cheapest place to buy a radiator is Rockauto.com.
Shoot a laser thermometer at the core of the rad and notice if the center of the radiator core is cooler. That will tell you if you have this problem.
If it's an 03 or newer GM read below.
If you are running an 03 or up GM they have a weird coolant in them called Dexcool. The cores of these GM rads that have aluminum micro fins are prone to developing a gummy blockage that are hard almost impossible to properly flush out if they have been contaminated with regular coolant mixed with Dexcool.
Have you added regular coolant in to top the cooling system that wasn't Dexcool? If you mix regular coolant in with this stuff it coagulates and causes this awful goop that is hard to flush out of the system.
GM service trucks that spend a lot of time idling like utility trucks, telephone trucks and carpet cleaning trucks are prone to this gunk up. The cure is a radiator replacement. Cheapest place to buy a radiator is Rockauto.com.
Shoot a laser thermometer at the core of the rad and notice if the center of the radiator core is cooler. That will tell you if you have this problem.
the 250 degree temp was when driving .. 2004 chevy express 6.0 .. I had this problem earlier this summer .. the dealership replaced a water pump and pump fan along with recharging the a/c .. it seemed to work fine for awhile ..I just sold the van and the guy drove it from NY to VA ..he called to say while he was driving up and down the hills of PA with the a/c on, the temp rose as high as 250 ..he turned the heat on, the temp dropped down to normal.. it does have 74000 miles on it maybe the radiator is shot? gummed up or something I usually take it to Valvoline for a full service oil change .. maybe one of the guys put the wrong fluid in .. thanks for your help
Bob Foster
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That's exactly what happened to my 2003 GMC 6L. The laser thermometer told the tale. We completely and thoroughly flushed the complete cooling system two times and it still was not cured. Put a new rad in and that solved it.
KevinL
Supportive Member
I just paid $1000 to replace the heater core in my 2001 blazer with the gunked up dexcool. I believe they started using this stuff because it's better for the environment and it won't kill a dog that might drink it.
Contemporary Carpet Clean
Member
yeah wont kill a freakin dog....but kills your wallet....I agree how can a product as common as anitfreeze solidify...OIL wont do that if you mix viscocities....or how about different WINDSHIELD washer fluids....u can mix rain-x with the blue stuff...no problems.
Art Kelley
Supportive Member
My 2003 Express 6L has been prone to overheating or at least running too hot since I bought it, I'll replace the radiator this winter and see if that helps. One thing you have to check on direct drive units is the coolant level in the heat exchange unit. My truck would overhear and shut down even while drivimg because I didn't bleed the HX system after a coolant flush. On the WM you open the bleed plug and keep pouring fluid into the radiator until fluid pours out the hole. That stopped the overheating.
Farenheit251
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- Oct 9, 2006
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- 732
On my white magic 1200 I had to unscrew the plug on top of HX box and then slowly trickle water from a hose into the radiator while the van engine ran(leave machine off). Was told it could take up to 30 minutes to get all the air out. Really no way your auto mechanic would know to do this. Fortunately it doesn't freeze here because there was no way for me to know how much coolant was left mixed with the water.
