2004 Tahoe Overheating

[Marky Dissod]

If / When you replace the radiator, use (either) air (or better yet water) to clean out the AC condenser fins.
Push the air / water through from back to front so you don't get anything stuck in the condenser.

That'll improve the airflow through the AC condenser as well as the new radiator.
This gets too often overlooked.

 

[irwires]

Thanks for the info. We’ve not flushed to coolant, but I figured with all the heater hose replacements and topping off, we’ve probably swapped out all the coolant at least once in the last 8 years we’ve owned the truck. I’ll use one of my coolant test strips to confirm it’s ok. I’ll bet an upsized radiator would be a good idea. Do you recall which one you installed? The fan clutch is a year old, but worth checking. How do you test for a bad fan clutch?

 

[irwires]

First off any rubber hose (radiator or heater) will evaporate the water and coolant slowly thru the openings between the molecules of the rubber. Especially under pressure and heat.
Next, chances are your mechanic put on a aftermarket fan clutch. Typically they loose 100-150 rpm per year due to cheapness.
With the age of your truck don't bother to test the coolant. Do a super good flush, change the water pump, fan clutch, thermostat and radiator and all hoses using all GM parts. Also change the temp sensor sender, drive belts and tensioners. This will put you back to original condition. Any problems after that should be simple to find. Here in Arizona I automatically change everything every 4-5 years. The 04 Tahoe now has 200K and never a problem.
Taking a chance on overheating the engine will cost alot more than replacing the parts.

 

[adriver]

240F is something that shouldn't have gone on long term.

I would check the clutch fan. I've had a bad mechanic that didn't know, but the clutch fan has a shim. If they replaced it, and didn't replace/use that shim, then your fan will not operate properly. Sitting in hot traffic might be getting no air flow. I would see if when it's hot, if the fan is even coming on. Without a fan, and sitting in 100+ degree heat, would cause it to get that hot.


"a CUP of coolant a month"? Que?