Community Forums

hunterstuart · 09-10-2018, 05:13 PM

We bought a 2009 GMC Sierra 2500HD to pull our 15,000 pound 5th wheel. It seems to have plenty of power, but it overheats quickly when heading uphill. Suggestions for modifications to keep the engine cool??

gbgeezer · 09-10-2018, 07:22 PM

We've experienced this ... was caused by fan clutch failure to engage the fan. When it engages the roar can be heard in the cabin. Hope this helps. We've had this happen twice in 160k+ miles.

phfkef · 09-10-2018, 07:48 PM

Getting rid of heat buildup is always of interest. The fan may be part of the problem.
I found this to be a very instructive read; http://www.maxxtorque.com/2008/07/du...n-and.html?m=1

gbgeezer · 09-10-2018, 10:07 PM

Thanks for the great article. Will have to look into it further.

Sk Sierra · 09-11-2018, 03:46 AM

Interesting article. But the lly is 2 generations older than your lmm (which is basically an lbz with emissions). If it were my truck, I'd be looking at the cooling stack to see if it's all plugged up between the intercooler and rad. It's a pretty common thing if you google duramax cooling stack cleaning. You'll find all kinds of articles and how to threads on the duramax forums. If that checks out then I'd be looking at the fan clutch.

phfkef · 09-11-2018, 06:31 AM

SK, I have a new 2018 duramax with the external hood scoop. I had only associated it with better performance. The article highlights the importance of good cool breathing too. Yes, the radiators are the prime suspects.

Sk Sierra · 09-11-2018, 07:06 AM

Oh definitely, no question there.

Bipeflier · 09-22-2018, 05:50 PM

Have the clutch fan engagement checked and radiator cleaned.

phfkef · 04-02-2019, 07:29 AM

Quote:

Originally Posted by hunterstuart

We bought a 2009 GMC Sierra 2500HD to pull our 15,000 pound 5th wheel. It seems to have plenty of power, but it overheats quickly when heading uphill. Suggestions for modifications to keep the engine cool??

I'm wondering what the resolution to this was? Anything further?

hunterstuart · 04-03-2019, 08:35 AM

Banks Power aftermarket systems; intake, computer chip and exhaust. May also replace the radiator with new one or Banks Power replacement.

Hope that helps.

grindstone01 · 04-03-2019, 08:46 AM

Keep a eye on the coolant level in your overflow bottle. If you over heat a Duramax (any motor) there is a higher risk for creating a head gasket leak which can be a small leak and take months to show up.
If your motor is overheating, don't ignore a red flag, get it checked out and fixed, cause something is wrong!
I agree that the newer Duramax's have a hood air scoop which helps for cooling, but it also has 80 more horsepower than the 09 Duramax and that needs the additional cooling.

08Carriage · 04-03-2019, 12:43 PM

Are you using Tow haul? If you are not the transmission will generate more heat.
What is the transmission temp?
Heat will transfer to the radiator

Old-Biscuit · 04-03-2019, 12:47 PM

2009 2500 and a 15,000# 5th wheel.....maybe that Duramax is working too hard

grindstone01 · 04-03-2019, 07:13 PM

Quote:

Originally Posted by Old-Biscuit

2009 2500 and a 15,000# 5th wheel.....maybe that Duramax is working too hard

The Duramax and Allison powertrain is a good fit for that load. The 2500 truck platform is a little light with it's brakes and suspension design but the motor/trans is the same as used in the 3500, 1 ton.