so today was hot...

[f5fstop]

Originally Posted by Michael1

I wouldn't do any of this. I would complain to the dealer. Something is not right here, and may not be right with an entire block of production. It could be the fan clutch, the radiators, fan pitch, etc. The H3s should not be getting this hot. You're not even towing a trailer! GM has higher standards than this, so either engineering screwed up, or the supplier is providing parts which are out of spec. You should be able to tow a fully laden trailer (3500 lbs with manual, 4500 lbs. with auto), up a grade (such as the eastbound 15 Baker grade in California) at 100F with the A/C on full at the speed limit (or as fast as the truck will go). If it can't do that, there is something wrong.

Michael

Agree take it to the dealer. If the coolant is that hot, you don't want to mess around, especially with an aluminum block/head engine. But let's add in the fact it might not be the coolant overheating, it might be a sensor is bad and giving a bad signal to the PCM. A tech with the Tech 2 can determine this in minutes.

Other point, if you are driving at speeds above 30-40 mph, no fan in the world can draw any more airflow through the radiator, than what is being pushed in by the movement of the vehicle.

Do you have any restrictions in front of the radiator?

As I told someone on another thread, if the sensor is ok, have the dealer to a drain and then a Vac-and-fill of the coolant system. If there is a possible air bubble in the engine, it can cause overheating, and this has been a problem with some of the Ecotec 4-cylinder engines. Haven't heard of any problem with the Vortec inline engines, but who knows. The vac-and-fill method prevents any air bubbles from forming inside the block. Just some ideas from my easy chair