2005 GMC 2500HD overheating

[Copperlisa]

This heat wave in the West is causing havoc. The truck is overheating without the 5th wheel on...and I need assistance. Engine temp is just above 210, and the tranny temp is right about 200. I'm sure the AC has something to do with it, because the lower I turn the AC, the more stable the temp is. Radiator is full.

Please give me some ideas of what to look for and what to not be taken advantage on. My dad was a professional mechanic and passed on two years ago.

Thanks!

[Amdavis76]

Although I have a 1500 with the 5.3, it is set from the factory to run at 210. Whether it is cold or hot (like when towing my boat last week and it was 107 degrees outside) it is always at 210. Transmission ran about 183 - 185 and would creep up to 200 - 203 in traffic. This is on a 2013 truck with only 2500 miles on it.

Good Luck!

[Norskeman]

My last truck was a 2005 Chevy 3500 SRW - duramax/allison. I had the same temps - most of my towing was on the east coast. The fan clutch should kick in when pulling hills when the engine temps goes higher.

The allison tranny temp will "follow" outside air temp when it gets hot out. The dash gauges are not as accurate as a digital gauge.

I have an Edge CTS on my truck - tranny temps are the same as the DIC (digital). Engine temp is 20 degrees cooler on the Edge - dash gauge being analog is not as accurate.

I have the coolant flushed every 4 years. (per the manual - 5 years or 150,000 miles - Using coolant other than DEX-COOL may cause premature engine, heater core, radiator and fuel operated heater (van models only) corrosion. In addition, the engine coolant may require changing sooner, at 50 000 km (30,000 mi) or 24 months, whichever occurs first).

I use TranSynd in the tranny - synthetic and rated for higher temps and less oxidation when it gets hot (greater than 265 degrees)

Rotella T synthetic in the engine

Mobil 1 synthetic 75X90 in the front and rear diff.

[nevadanick]

The 160 temp it was running earlier is to cold. 210 is a more normal temp for today's engines.

[Copperlisa]

I've got low miles. Just rolled 131,000. Got a clean air filter. So, I'll be out to mess around on the highway today to see what I can learn. I really appreciate all of you guys helping me out. My hubby's on the semi, and he can only do so much from where he is. Southern Idaho is cooking again today...so I should be able to figure something out.

2005 GMC Sierra 2500HD 6.0
1998 Jayco Designer 29RKS

[Engineer9860]

45Ricochet wrote:
Check out Killerbee.com
It's not unusual and many guys on this board use his products with the 2005 DMAX engine.
I assume your in S Idaho which was like 110* today. A 8 year old truck will run hot in those temps though. I won't link the funny video on Youtube cause it gets panties in a bunch in the bowtie camp :W
Just curious as to your miles.
Good luck

You didn't catch this part before you started to gloat did you Ric? :w

#40Fan wrote:
She has the 6.0 gas, not the Duramax. Other than the warm transmission temps, the engine temp seems fine for the weather you are in. I wouldn't waste money at a mechanic's shop and just go to the local car wash and give the front end a good cleaning.

[ls1mike]

It is fine with those ambient air temps. Drive it.

[FishOnOne]

kaydeejay wrote:

OH48Lt wrote:
Nothing wrong with those temps. I wouldn't do anything to it other than make sure the radiator fins are clear, visual checks on the belt. Compressed air on the various radiators and coolers, from the engine side to out the front. Don't use water if the parts are hot !!!!!

X 2

X3... I agree nothing to see here. Keep on truckin!

[_40Fan]

Slow speeds will get the transmission temp up quickly. Still that engine temp is fine.

[Copperlisa]

Now that is a good question. It's been mostly slow speeds around town. So...out on the highway tomorrow for an experiment, and then to the car wash after a cool down. I haven't noticed the fan kicking on and off at all...which isn't a good thing either. Something else to check. You guys are awesome to help me out!


2005 GMC Sierra 2500HD 6.0
1998 Jayco Designer 29RKS

[Bob_Olallawa]

Can you hear the cooling fan lock in and if so is it locking up for long times or just in and out. Are you slow speed around town or highway speed for good air movement. The temp gauge on these GM's are not the most accurate but unless the fan is staying locked up for a long time I would say you don't have a problem.

[Copperlisa]

The owner's manual says the tranny can run 265 before it's "too hot". Red zone starts after that. I can use the compressor on the radiators and coolers. What about the AC condenser? How do you clean that? The belt looks good. We just changed plugs and wires, and checked it then. I'm assuming this truck had some use before we bought it.

I'm just trying to take care of what we have now. My hubby runs long haul, so I get the maintenance duties.

2005 GMC Sierra 2500HD 6.0
1998 Jayco Designer 29RKS

[kaydeejay]

OH48Lt wrote:
Nothing wrong with those temps. I wouldn't do anything to it other than make sure the radiator fins are clear, visual checks on the belt. Compressed air on the various radiators and coolers, from the engine side to out the front. Don't use water if the parts are hot !!!!!

X 2

[hmknightnc]

#40Fan wrote:
She has the 6.0 gas, not the Duramax. Other than the warm transmission temps, the engine temp seems fine for the weather you are in. I wouldn't waste money at a mechanic's shop and just go to the local car wash and give the front end a good cleaning.

X2 on this. First things first. Clean all the radiators/coolers in the front end at a car wash. With that old a vehicle and no idea what maintence/care and your symptoms I suspect your coolers/radiators are extremely dirty/clogged not allowing proper air flow.

If washing/rinsing doesn't work then have a mechanic flush and refill radiator fluid and change T-Stat.

[OH48Lt]

Nothing wrong with those temps. I wouldn't do anything to it other than make sure the radiator fins are clear, visual checks on the belt. Compressed air on the various radiators and coolers, from the engine side to out the front. Don't use water if the parts are hot !!!!!

[_40Fan]

She has the 6.0 gas, not the Duramax. Other than the warm transmission temps, the engine temp seems fine for the weather you are in. I wouldn't waste money at a mechanic's shop and just go to the local car wash and give the front end a good cleaning.