Overheating ???

[BOB-AUSTRALIA]

Gday My recently purchased lmm engine 2500 silverado heats up almost to the mark between 210 & 260
then the fan roars and returns back to 210 It only does it on long uphills when towing my 3500 kg caravan
Which i think you call a travel trailer My question Is this normal for this model?
Any advise would be greatly appreciated As information on this model here in australia is hard to find
Thanks in advance Bob

[DmaxMaverick]

Return to basics. The fan (clutch) is controlled by the thermostat, or more accurately, the temperature of the coolant (air) passing through the radiator. If the fan is engaging later than you like, you will need to adjust the thermostat, or its control (if it's electronic, as are some late models). Electronic controlled thermostats are adjustable with programming, or calibration updates. If it's a traditional thermostatic controlled thermostat (mechanical), replace them with stats that operate in the range you want/need. If it's still not aggressive enough for your needs, more aggressive fan clutches may be available, or mods to your model may be an option.

Another option is to reinvent the wheel. Toss the old technology and rethink it. Evan's NPG is another route to healthy engine temperature control. Simply, don't worry about it. NPG (Non-aqueous Propylene Glycol) is an engine coolant that doesn't boil, and operates normally at zero pressure. It contains no water, so no boil. It moves the heat out of the engine without the need for a pressurized system. I've not experimented with it myself (and I have no vested interest in it), but the principal is solid. It costs a bit more than traditional coolant, but it's non-toxic, and offers a benefit to the cooling system, in that it, operates at no pressure. Seals, clamps and components simply don't leak, as they can under traditional conditions. I've heard plenty of skeptical reviews of it, but no anecdotal complaints of performance or failure. It has drawbacks, but an otherwise healthy system will integrate it well.

[a5150nut]

Bob do you have a Pyrometer on your truck? My 06 LBZ can run exhaust temps up empty and in turn engine temps. Larger tires can effect temps also. On m y 94 6.5 I had 411s and running 285/85/16s had to correct the speedometer to 373s to read right. Kinda like running up hill.

[BOB-AUSTRALIA]

No I don’t have a pyrometer Still running stock wheels and tyres I read in the owners manual that it is normal but if it gets up to 260 it’s more than the cooling system can handle Just seems a bit strange most of our Aussie cars stay around the middle of the gauge or you start worrying

[Yukon6.2]

Have a good look at the radiator and between the different coolers.
Make sure they are clean and there is no buildup of stuff between them.
sometimes an oil leak will create enough mist to plug the fins on the rad with oil and stuff.

[BOB-AUSTRALIA]

Fitted a new genuine radiator removed intercooler washed out a/c condenser and intercooler did improve but still does the same just have to live with it

[JohnC]

If, when your fan kicks on, it cools down, then it sounds like you have an airflow constraint. Since you've cleaned everything out, you may be up against the limits of the fan clutch. I'd send a PM or email to John Kennedy of Kennedy Diesel. Over the years he's done a lot of work with thermostats and fan clutches and may have a suggestion or two.

[Yukon6.2]

Could the gauge be out of wack?

[JohnC]

Yeah, what does the gauge say when you're just tooling along unloaded?

[BOB-AUSTRALIA]

It always sits just under 210 if you’re not towing

[Yukon6.2]

I know it might be a pain, but i would add a second gauge to verify the OEM gauge.
If you had a 6.5 then those temps could be normal...
My Dmax runs cool even in the summer and it has probably had zero maintenance on the cooling stack.Dmax's are not known for overheating, especially not hauling any weight

[JohnC]

Might be cost effective to just change the thermostat and see if anything else changes. Running at 210 doesn't give you much head room before the fan kicks in.

[BOB-AUSTRALIA]

I have reread the owners handbook and think I’m worrying to much It says gauge shows engine coolant temperature It also provides an indicator of how hard your vehicle is working.During a majority of the operation the gauge will read 210 or less.If you are pulling a load or going up hills it is normal for the temperature to fluctuate and go over the 235 mark.However if the gauge reaches the 260 mark It indicates that the cooling system is working beyond its capacity

[DmaxMaverick]

I have reread the owners handbook and think I’m worrying to much It says gauge shows engine coolant temperature It also provides an indicator of how hard your vehicle is working.During a majority of the operation the gauge will read 210 or less.If you are pulling a load or going up hills it is normal for the temperature to fluctuate and go over the 235 mark.However if the gauge reaches the 260 mark It indicates that the cooling system is working beyond its capacity

If, in fact, your gage indicates only midway BETWEEN 210 and 260, then no worries. That is absolutely normal when loaded and/or working hard. Your original post seemed to suggest it was running up to 260F frequently when loaded, to me, anyway. Anything over 240, except during extreme loaded and heavy use, would be reason for concern, if the cooling fan didn't bring it down quickly. If it isn't exceeding 235 during loaded or heavy use, don't lose any sleep over it. It's normal. Mine has reached that level, and a bit more, but I was hauling at GCWR+ up a long 6% grade, on a 118F+ hot summer day. Turned off the A/C, opened the windows and enjoyed the wonderful noise of a howling cooling fan. Sure, it was hot, but short lived. I've repeated that episode many times, and it survived. On the upside, A/C is free, and beneficial, on the downhill side. Also note, I have upsized tires, which increases the effective rear gear ratio to about 3.42 (speedo/odo corrected to that with programming).

[BOB-AUSTRALIA]

Thanks for all the replies I really appreciate it I’m heading off for 6 months at the end of February from Victoria in the south east of Australia across to the west coast and up north to Darwin where it’s not unusual to see temperatures reach 46 degrees Celsius so with everyone help it’s put my mind at ease Thanks again Bob

[a5150nut]

. It's normal. Mine has reached that level, and a bit more, but I was hauling at GCWR+ up a long 6% grade, on a 118F+ hot summer day. Turned off the A/C, opened the windows and enjoyed the wonderful noise of a howling cooling fan. ).

Was that going up 395 out of Bishop?
Moving from Riverside to Susanville wife was driving my 74 C2500 pulling my 54 Ford with 283 and 4 speed. Hit that hill and it pulled us down real quick. I had her stop and I hopped in the Ford still hooked up with tow bar. I told her when I wave at you start driving. She started to roll and I dropped the Ford in gear and up the hill we went, 65 Mph. Passed a CalTrans crew and they must have radioed ahead, as we crested the grade the rest of their crew was cheering us on. To many years running push pull scrapers I guess.

[DmaxMaverick]

My son has some experience with the push-pull scraper (he's working on his journeyman heavy operator). It takes teamwork and communication, or it just makes a mess.

I've pulled the Bishop grade, but not in my current rig. I've done it a few times in a 74 Freightliner with a small cam 350, at about 78K, in a previous life. Had to get into the deep holes if there was a headwind. Most of the passes I've done with my current rig and RV have been Grapevine (HOT), Tehachapi, Cuesta, Pacheco (HOTest), Donner, and a few others I don't recall, to include a 2005 trip to SLC for the rendezvous.

[More Power]

Any accessories on the front of the truck that could block airflow?
What's the outside air temperature when the engine temps seem too high?
Exhaust particulate filter in good shape? Not plugged?

[a5150nut]

My son has some experience with the push-pull scraper (he's working on his journeyman heavy operator). It takes teamwork and communication, or it just makes a mess.

Is he working in 12 or 3?

[DmaxMaverick]

Is he working in 12 or 3?

OE3, a couple years now. He started equipment and CDL at county road dept, so he had a head start. They keep him busy. A lot of them get sparse work, thinking they don't pay attention to lazy.