5.3L Runs Hot......Anyone Else???

[Wxman]

I have an '03 TB EXT with the V8. The engine runs hot when outside temps are high (low 90's+). It doesn't overheat, just runs hot, sometimes over 235. This is not loaded, climbing mountains or towing. It is usually during city driving, but not necessarily heavy traffic. Has been in for service multiple times. Has had three new clutch fans, PCM update, reprogram and then total replace, new thermostat, flush and fill, and maybe more. Local dealer is out of ideas and apparently HQ has not been of any help.

Curious as to experiences of any other V8 drivers. Warranty is out in approx 500 miles.

Thanks
Wxman

[ScarabEpic22]

Welcome!

I havent heard of this happening before, my 02 4.2L I6 runs a hair below 210 all the time, except for the time I was towing my 3900lbs boat up Snoqualmie pass at 70... :D Had to get to the lake quick!! :laugh: Then it ran at about 230-240. Had to back off to 60 a mile before the summit, but it was fast while it lasted. I know someone here can help, as I dont have the V8.

[OurZoo]

Never been an issue for me in the 16 months I've had it. In addition, the hottest its been out here by me this summer was probably 107.

[rcam81]

Mine has been running cooler since I switched to Mobil 1. Now the temp stays at 195.

[Dave]

Mine was running hot until they replaced the fan clutch and reprogrammed the PCM. Could be a water pump going bad.

[KNBlazer]

My 2004 Blazer EXT was running hot at 235 degrees in Rush Hour Traffic with temps in the 100's. It would cool down once I hit 65, looked under the hood and noticed the fan clutch was hardly moving. Took it in to the dealer as it is still under warranty and was replaced. Final diagnosis was a worn fan clutch and excessive play which ended up damaging the radiator final price $1100.00 billed to the warranty.. :no:

[carbonvoy]

What do you guys consider normal? My '03 Sierra 5.3 consistently runs 195-200, and never really moves. My wife's new Envoy ('05 around 2500 miles) 5.3 always runs at about 215 on the guage. I figured it was just a variance in the calibration of the guage or sending unit. Do you think the Envoy runs too hot? What is normal for a Trailvoy with the V8?

[Dave]

Mine usually stays below the 210 (half way) mark. It did until the fan clutch start going bad. Now it is back under 210, but ofcourse it is cooler. Until the fan clutch went bad, I never saw it above 210 and that was even after climbing long mountain grades (not towing though) or idling in 100 degree heat.

[02Bravada]

Wxman make sure that you get to the dealer and have the service manager write up a repair order explaining your problem and put it in your records. This is called a pre-existing condition and they should help you even after the warranty is out if it has not been corrected. Make sure they preform Bulletin # 04-06-02-005 doc #1539442 reprogram pcm. This will cause the pcm to command more on time to the electro mechanical fan clutch. The bulletin release date was july 27,2004. Also make sure that they blow out your ac condenser and clear the condenser and radiator of any bugs or crud buildup. This should bring down the temp by runing the fan at a higher rpm usually 300 to 500 rpm. replacing the fan clutch without the reprogram will not get the job done. Make sure the guy using the Tech II programmer has the latest update from GM tis on their GM access server. Good luck let us know what they find. :)