Overheating 5.3L LH6
10-28-2009, 12:14 AM
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Overheating 5.3L LH6 Overheating 5.3L LH6
My GMC Envoy is starting to overheat. Its happened 3 times already and all 3 have reached 260*.
First time i didnt notice it was overheating because the gauge took a while to go up. I was racing and was spraying the 100 shot of nitrous. Added water and was fine while driving regular.
1 week later I was racing it again on the nitrous and temps went up again. Made it home and took out the radiator and thermostat. Radiator had a blown gasket on the lower plastic part. Got it fixed and cleaned out. Also tested the thermostat and drilled 2 small holes so more coolant can flow while its closed.
So last weekend I got on the highway and was racing it on motor only and truck still overheated. It was the first time it overheated on motor.
I dont know why its overheating. I checked the coolant level and it seems full, even while its running at idle. I have my e-fans on at 100% all the time and a 160* thermostat.
Seems like when Im driving regular the temps are fine. But when i race it, the temps go up. I know the transmission isn't overheating, its the engine. Oil pressure is always between 40-60 psi and never drops. I have been scanning with wideband and ive noticed its running very rich, sometimes between 9.9-11.2 AFR at WOT. Could that be the problem? I havent had time to retune it for AFR. When I did the last tune on it, the AFR was at 12.6-12.8 at WOT. I dont understand how it got rich all of a sudden now. Its not making any weird noises.
Mods are in sig...
My GMC Envoy is starting to overheat. Its happened 3 times already and all 3 have reached 260*.
First time i didnt notice it was overheating because the gauge took a while to go up. I was racing and was spraying the 100 shot of nitrous. Added water and was fine while driving regular.
1 week later I was racing it again on the nitrous and temps went up again. Made it home and took out the radiator and thermostat. Radiator had a blown gasket on the lower plastic part. Got it fixed and cleaned out. Also tested the thermostat and drilled 2 small holes so more coolant can flow while its closed.
So last weekend I got on the highway and was racing it on motor only and truck still overheated. It was the first time it overheated on motor.
I dont know why its overheating. I checked the coolant level and it seems full, even while its running at idle. I have my e-fans on at 100% all the time and a 160* thermostat.
Seems like when Im driving regular the temps are fine. But when i race it, the temps go up. I know the transmission isn't overheating, its the engine. Oil pressure is always between 40-60 psi and never drops. I have been scanning with wideband and ive noticed its running very rich, sometimes between 9.9-11.2 AFR at WOT. Could that be the problem? I havent had time to retune it for AFR. When I did the last tune on it, the AFR was at 12.6-12.8 at WOT. I dont understand how it got rich all of a sudden now. Its not making any weird noises.
Mods are in sig...
