Hey guys I wanted to know if the fan on your H2s is on all the time. My coolant can't reach optimal temp even while going on the highway it goes only up to 176 F. When the car is idling it won't go past 149F. I've checked temps with an OBD tool so a faulty gauge is not the case.

The thermostat was replaced twice and it is opening and closing properly as we've checked.

I'm starting to think that the fan clutch could be bad and I'm not sure if the fan should start straight away and keep spinning all the time while driving.

Thanks for any input on this case.

 

Ok I found out that it SHOULD actually be on all the time except that while the engine is cold the RPM should be minimal. However mine even when cold started goes wild after like 10 seconds. My question is if this could be a fan clutch or something else ?

 

Are you talking about the mechanical fan?

I just want to make sure.

 

Yes, exactly. It should start slow when the engine is cold and speed up once the engine gets hotter. Mine just goes berserk at the begininning.

 

Malcolm745, this is directly from the manual in my 2003 H2, maybe it'll help shed some light on what your experiencing:

Hope it helps!

 

It certainly could be that the clutch on the fan is bad making it lock up all the time.

That would make it spin faster than it should be hence cooling your hummer down more than needed and why you can't get up to temp.

If it is really loud and locked up completely and making a loud WHOOOOSH that doesn't go away once you start driving and stays like that your clutch is probably bad a stuck locked up.

 

Wow thanks for the screen from the manual. The part when it says "under heavy vehicle loading, trailer towing and high outside temperatures the fan speed increases" well mine does that while there is -3F outside which can be a pain cause it won't let the truck reach operating temperature.

Yes it does that "whooooosh" sound and it feels like it's eating up a lot of power while at it.

I also heard that when the engine is cold I should be able to spin the fan by hand so that it can rotate freely mine however can be rotated but it feels to tight to move on it's own after that. I'll order a new hayden fan clutch today. Do you know what wrench will I need to remove the fan clutch ? I heard it's a 7/8" but I want to make sure to be prepared.