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!

[_40Fan]

Glad to hear that the car wash and your extra looking paid off. Time to head to your next destination.

[wintersun]

Lots of things can cause an engine to run "hot" including low coolant, slipping fan built, thermostat that is not opening all the way, old radiator hoses where the intake hose is collapsing, timing off, and lastly a bad head gasket. The last is important as the early LLY engines had a bad head gasket design and they were not reliable. If the head gasket blows it can initially put hot gases into the coolant but eventually it can put coolant into the motor oil and then the engine is toast.

I look at a high temp or similar symptom as an early warning sign and the sooner I find the problem and fix it the less costly it will be in the long run.

[lazydays]

I have an 05 and monitor my gauges with an Edge Insight. My tranny truck gauge is pretty close to the Edge. The water temp. is another story. Once I hit around 186 on the Edge, my truck gauge hits 210. Big difference.

[Copperlisa]

That's NOT something I want to hear!! 😞 Water pumps are supposed to behave themselves and not fail, slowly or epicly. One of the reasons WHY I am so anal about watching my gauges.

2005 GMC Sierra 2500HD Ext. Cab 4x4 6.0
1998 Jayco Designer 29RKS

[steiny93]

we have a pair of gm 6.0's (one in a 2500hd and the other in a denali) both run around 210 engine and 180-220 on trans

both have also lost water pumps; the 2500hd started slowly leaking so had it swapped; denali failed epic'ly and the engine got very hot very quick (like within 10 blocks from cold start)

[C_Schomer]

I trust t-stats about as far as I can throw them. I've seen too many bad ones before 60k miles. Mine was getting hot and a t-stat helped and then pressure washing the radiator made it cool like a new truck again. Craig

[H2oSprt]

My 2004 6.0 runs at 210 everyday and always has once it's warmed up. You are good at 210, I crossed Vegas yesterday with my camper on and it went a bit higher than that, but outside said 115!!

[ls1mike]

The GM 6.0 gasser is a solid engine. I have been very happy with mine.

[bmanning]

Copperlisa wrote:
I owe you all a big thanks. You saved me a ton of money, and reassured me to boot. After a session at the car wash this morning (I pulled the shroud and there was enough trash between the radiators that you could have built an eagle's nest!) and a full day of stop and go running around in 100+ heat, the tranny was solid at 165, and the engine at 205. The fan clutch was kicking on and off, because I could feel the difference in the AC in both force and coolness.

So...I'll hang out on the forums for a while and see what else I can learn from y'all. Thanks again!

2005 GMC Sierra 2500HD Ext. Cab 4x4 6.0
1998 Jayco Designer 29RKS

Glad it worked out! And hats off to you for putting in the effort; some others might've immediately taken it to a dealer or shop and potentially (not necessarily, but potentially) get taken for repairs that were never needed. Or, rather than dishonesty you could've encountered incompetency and had some rookie tech throwing parts at your truck without ever pulling the shroud to check for debris as you did.

And yes, lots to learn on this forum, and over time you'll get really good at filtering the great advice from the nonsense (there's an abundance of both on rv.net!).

[Copperlisa]

I owe you all a big thanks. You saved me a ton of money, and reassured me to boot. After a session at the car wash this morning (I pulled the shroud and there was enough trash between the radiators that you could have built an eagle's nest!) and a full day of stop and go running around in 100+ heat, the tranny was solid at 165, and the engine at 205. The fan clutch was kicking on and off, because I could feel the difference in the AC in both force and coolness.

So...I'll hang out on the forums for a while and see what else I can learn from y'all. Thanks again!

2005 GMC Sierra 2500HD Ext. Cab 4x4 6.0
1998 Jayco Designer 29RKS

[45Ricochet]

Engineer9860 wrote:


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

Her post right before mine was within 10 minutes and she added a Sig to boot. No gloat, I just had to remove all the Links I was going to put in my post. Maybe I should speed up my typing in the future :W

[Copperlisa]

You guys are awesome. I feel much more comfortable now. This 2500HD 4x4 is a heavy girl. I'm just leaving now to go give her a bath. Then I'll do some test runs. Thanks so much!



2005 GMC Sierra 2500HD 4x4, 6.0
1998 Jayco Designer 29RKS

[bmanning]

My 2008 5.4L F250 runs 220-225 under normal everyday conditions; the factory gauge doesn't move from the middle but my Scangauge II keeps me informed.

Ran the gamut: new coolant, new t-stat, new cap, fan clutch & water pump in perfect working order...the little V8 just runs a bit warm hauling around a 7200lb 3/4ton 4x4.

Everyone, even respected techs I know, swear it will run days on end at those temps, no problem.

I'm still learning to live with it...too many years of having engines run 193-204 to just accept it...

[transamz9]

Bob/Olallawa wrote:
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.

The fan usually won't "lock up" until around 230* water temp. The A/C being on should how ever cycle the fan up and down.