Ok I have had this running hot while plowing problem too long, and need to figure out what i can do to resolve it. Here is what we are working with, 1999 year truck, No log cooler, no condenser in front of the radiator, radiator was pulled out a couple years ago and cleaned because of all the oil and dirt in it, a few of the fins are bent over , but i straighten out alot of them. Transmission has a derale external cooler with fan on it 25000 gvw unit i beleve. I also replaced the fan clutch a couple years ago, and it made no difference. This truck weighs in at 11,500 pounds fully loaded with its 10 foot plow on the front, and sidewing plow, and salt spreader. It also has the 3:55 gears in it. My thoughts are the gearing is too tall for plowing with this engine. Because I can run it in low range and the temps will go up , and down because the rpms are turning faster. In high range i am bulldozing huge amounts of snow at 1500 rpms... thoughts ?

 

Did you try electric fans yet?
Is radiator original? Check to make sure it isn't restrricted. Try a 180 degree t-stat yet? I use electric fans and works great when towing boat and with camper on truck to keep temps down.

http://streetperformanceusa.com/i-95...FSTZQgodRmkA6w

 

How hot is hot? Could the snow powder possibly be blowing up over the plow and clogging up the front of the grille area? Your weight is really not a huge issue unless you're just not getting enough air across the radiator. There's no blockage in between the fins of the radiator is there? Just finding possible reasons here for overheating. When was the t-stat and/or water pump last replaced?

 

A small low-CFM fan pushing air back through the radiator onto the fan clutch could help as well. You're not moving fast plowing, and could be not getting enough air to the clutch to kick it in. I know it's a problem with our duramaxes in the summer.

 

Do you have a rubber flap on top of the plow.I work for a local town and we have problems with our trucks if they do not have the flap[10 in.of rubber belting]

 

This is my thought too. Lots working against you here:

- road speed too low for good airflow through rad

-plow blocking grille from airflow

-engine RPM probably too low for fan to do much good

-torque converter working really hard with this type of work and generating lots of heat

As mentioned above, auxiliary electric fans may help a lot. Also, eliminating the fan clutch for a direct drive fan may help too.

 

I know a direct drive fan will work, but I wonder what will happen to the heat If i go with that option. What are the options to make the fan direct drive ? This is while i am plowing, If i run down the road with the OD off i can keep the truck around the 190 mark.. I think the engine is lugging too much and generating a ton of heat, it needs more Rpms to keep the air moving..

 

Remove the thermostat completely?

When my thermo went bad a couple years ago in the middle of winter I could not get it past the left side of the indicator, it would get there then drop back down just above the 140 mark after a hard pull up the grades....

Just a thought.

 

Heat activates the fan clutch. IF rpm has anything to do with it, then it would lock at low rpm and freewheel at higher rpm. Unless it gets hot, then it will lock up until it cools back down.
(fan should freewheel most of the time at hwy cruising rpm and engage at idle).
BUT, can't say for sure if the problem is airflow, coolant flow, or something else. Modifications? Performance adders? Did it do this last year? What has changed?

Not done this before?
1) replace thermostat. With no thermostat one will stay cold forever. BUT, when it finally heats up...it won't cool back down.
2) Check fan shroud and make sure you are getting air thru the radiator. clean fins. Make sure snow/ice is not blocking them or in them.
3) replace fan clutch with a heavy duty, good quality part.
4) Replace radiator, or have it cleaned and the engine flushed.

IF performance adders have been added in between the last time it ran cool and now? Odds are, that's the problem. IF something has been changed in between...look there 1st,

 

Good points. I replaced my thermostat before it got too hot.

 

The 4th gen have a snow plow mode that engages the clutch fan while it's selected so if they are having a problem so will you, however if you keep it engaged the fuel economy drops drastically. My suggestion is make sure the rad is clean, remove the factory fan altogether then install electric fans. This will make sure you can have fast warm ups when cold have instant cooling from the AC when hot if you decided to reinstall the condenser and also keep the engine cool when plowing.

 

I had the same problem getting warm while plowing (back when I had the auto). Temps would get to the high end of the "normal" range, sometimes just peak over the line. Changed radiator, and installed a new fan clutch from Pepboy's. Wish I kept track of their brand/model number, because it works great for plowing. Kicks on anytime rpms stay around/below 1500 regardless of temp, and kicks on when the gauge gets around 190. Kind of annoying when I'm not plowing, but blocking the radiator fixes that. Now I barely see 190 unless I hit the highway with the blade on, then it might creep up to 200.

I also did try electric fans, dual 2k-ish cfm fans. They don't work nearly as good as the factory one, IMHO. Only nice part is they don't depend on engine RPM's. I guess make sure the trans is not slipping at all, making extra heat. Sounds to me though that your truck is getting a work out and needs some extra cooling, factory rad might not be totally clear inside. Good luck!

 

Since the radiator has not been out in a while and cleaned I would check that first along with replacing the T stat with a Cummins T stat. I ran my truck for 35 hours straight without shutting it off pushing 15" of heavy snow with my 2001 Dodge Ram and a 9' Boss with wings and never had it go up over 190 degrees. My truck does have 4.10's, however we have 2 other Dodge ram 3500 24v with 3.55 gears plowing full time and never had one get hot just from pushing snow.

Do you have an aftermarket trans temp gauge?

I have to push A LOT of heavy snow in order for my temp to reach 190.

Are you plowing roads or parking lots? And at what Speed??

 

Electric fans are weak. The alternator is not capable of delivering sustained power adequate to compare to the stock clutched fan. Bad mod on these vehicles.

If I were to guess, I'd say you just need a new fan clutch. When operating properly the fan clutch always has some force transmitted to it via fluid immersion. It still gets powered at high rpm with this force but nowhere near enough to keep up with engine speed. That's why it appears to operate at idle, but not at high rpm. But when it gets hot, there is a thermal clutch that locks it in to make it lock up. When locked it spins faster at idle due to full lockup, and matches engine speed at higher rpm for MASSIVE air cooling flow.

 

This truck has a Leece Neville 160 amp alternator, Power is not a problem with it. I plow parking lots with it. and one short half mile road. I had a diesel mechanic take a peek under the hood and he said the clutch was bad because cold it just free wheeled. so I will be putting a new fan clutch on and this electric 12 inch fan i just picked up.