ChasingHeat

Hello everyone. I wanted to update everyone on my progress. I had pretty much given up on finding the source of the overheating issues at idle. Until recently. My A/C cooling became less and less efficient. Until the cooling stopped all together. Took my Suburban to an A/C shop. Found a slow leak at the high side service port. All 134A eventually leaked out. Had this repaired and properly charged. Now the A/C is blowing ice cold again, front and rear. I can now sit at idle for hours with A/C on and the needle doesn't go past 210. The AC shop mentioned a low refrigerant level can cause overheating at idle with A/C on, due to the compressor overworking trying to cool, generating excess engine heat. Funny thing is I had the refrigerant levels checked by a local mechanic back when I initially created this post. Said all was good. Probably didn't hook up a gauge set to check low and high side pressures. It's going to get very hot here in Texas soon. I will update everyone on the status. Thank you to everyone who offered up suggestions.

Hello everyone. I am new here. I have a problem I've been chasing for quite some time. My 2004 Chevrolet Suburban 1500 5.3 liter V8 (original owner) will gradually overheat at idle with the AC on in the Texas heat. I've taken it to several mechanics with no luck. My next stop is the dealer as a last resort. Here is the scenario I can drive my Suburban with the AC on through streets or on the freeway and the temperature never gets above 210 on the dash. However if I pull into a drive-thru that has a long line or if its parked idling with the AC on for about 20 minutes the temperature will begin to rise and if I do not turn off the AC, rev the engine to above 1100 RPM for a bit, or shut off the engine it will eventually hit 260. With the AC off under the same conditions I can let it idle for hours and it never goes above 210 on the dash, even in 100-plus degree weather. I've changed the following components. Radiator, fan clutch(twice, first after market and later AC Delco), thermostat (installed cooler 165 degree thermostat), water pump, temperature sensor, AC compressor pully belt. All current components are AC Delco from the dealer. The upper and lower fan shroud is original OEM and in good condition. The fax blades are in good condition with no knicks or cracks. The serpentine belt looks to be in good condition. I cannot hear it slipping when driving or revving the engine. I've had the coolant flushed at a shop twice. Its not losing coolant or oil and not blowing smoke out the tailpipe so I have ruled out blown head gaskets. Otherwise it would be overheating all of the time. I read somewhere the issue may be the compressor (original) causing too much drag on the engine, causing the engine to work harder than it should at idle, resulting in overheating. I am open to any suggestions or ideas you guys may have. Thank you so much!