73shark

Welcome to the forum.

Did Chevy not put the electric fan on the GMT900 3/4 ton series like the 1/2 ton series has?

Francis Pedneau

My 2012 2500 has done this since new as well. It has the 6.0, clutch driven engine fan. The dealer did replace the thermostat under warranty, no change. At some point I would like to use this vehicle to tow a 26-30" RV. It does have the trailer tow package. It has got hot enough that the ECU shut off the ac compressor. Problems start when the ambient temp is 110F+. Also, just installed the second set of batteries (2) under the hood...heat kills.

SWHouston

I'd first verify temperature...

Get an A/C Thermometer (shaft type)
Remove Rad Cap when cold, start engine, and be prepared to remove/syphon off some coolant as it warms. Insert Thermometer and check for compatible readings.

Next, as long as you know your belt is tight, they make 9 and 11 blade fans for those clutch systems. You probably only have a 5 or 7 on it now.

You might also think about putting an Electric Booster Fan on it, which is thermostatically controlled.

Francis Pedneau

I checked the fan blade count on this unit, it has a 9 blade fan on it. If I change it to an 11 blade fan will I have to upgrade the clutch for it? At this time the ambient temp is not hot enough to induce overheat, the temp probe test will have to wait till next summer. The addition a pusher electric fan in front of the consensor, what brand/model would be good for this. Thank you for your help.

intheburbs

That doesn't sound right to me. I'm not sure you can just write it off as a design flaw.

I heaped some pretty major abuse on my 08 2500 this past summer, and the engine temp never went higher than about 220°. That includes pulling our TT on I-70 over Vail Pass and through the Eisenhower Tunnel, and also some slow, crawling fourwheeling in Moab in 100°+ temperatures (with the A/C on). Our GCW was 14,500 lbs.

Temp reading in Canyonlands (note the scenery in the mirror, engine was right at 210°):


And here's what my gauges looked like on the final approach to the Eisenhower tunnel (engine at ~220°):

SWHouston

You can do the Probe test at any time, all you're doing is verifying that what you're reading inside is consistent with what the Coolant temperature is actually.

If you have a 9 blade already, going to an 11 probably won't help all that much.

There are several good quality Electric Booster Fans available, go to EBay and do a search for your make/model.

Do you have a Transmission Temperature Gauge, if so, what's the maximum temp you've seen it at ?

Clayton Anstead

I understand this is a 3 year old thread however I would like to add to this. The 07-14 GMT900 2500 6.0L Suburbans all had issues with overheating and running out of gas while towing with 1/4 tank showing on gauge, I will address the overheating issue first. The clutch driven fan alone was not sufficient enough to cool the radiator properly when towing heavy loads or sitting at idle, this was a design flaw and know very well to GM, their solution to this was to throw new parts at it while under warranty in an attempt to wait out the warranty period while not solving the real problem of running hot and diminished AC at idle, their is however a real solution currently that was created by a third party by the name of Lingenfelter Performance Engineering, this company has a contract with the federal government to produce superchargers and performance equipment specifically for the GMT900 2500 Suburbans to be used for the FBI and such. They make a dual fan kit that consists of 2 pusher fans that mount in front of the radiator complete with mounting brackets and wiring harness that integrates into the factory distribution panel under the hood, it can be controlled 2 ways, by AC clutch or the ECM. If you choose ECM you will need to have the ECM reprogrammed. Also it's a good idea to upgrade the alternator to a higher output to compensate for the additional load on the electrical system. Now for the running out of gas problem, because of the dual fuel tank and the way it was designed when towing a heavy load the fuel management computer has a difficult time computing the distance to empty this in turn shows 1/4 tank when in actuality the tanks are empty. When you add gas to the tanks it first fills the secondary tank, once the secondary tank is full it spills over into the main tank, when the main tank runs down the computer sends a signal to the fuel pump in the secondary tank to transfer fuel into the main tank, this for some reason does not work when towing, the solution from GM was when you got below half a tank to pull over and shut off engine to allow the transfer of fuel..... not a good solution and currently I am unaware of a fix other than re-fueling the tanks before it gets down to 1/4. To my knowledge GM is fully aware of this and offers no real fix so you just live with it. Below is a link to the fan kit if you decide to address the issue properly.

Lingenfelter Suburban Yukon XL Auxiliary Fan Kit ECM Control 2007-13: Lingenfelter Performance Engineering