Overheating!

[CoachWagner]

I am pulling my trailer on our vaction through Montana today and it was really overheating. We have an 8000 lbs trailer and it was running hot ALL day. Yesterday it was great and I could hear the the fan come on when needed. today I couldn't hear the fan running and I really had to nurse it. Just before Helena the data area said the engine was overheating and I had to pull over at the summit. Will a fan clutch be intermitant in engaging like that from day to day? I checked codes and there were none. I am not loosing coolant. I am thinking the fan clutch is bad. Any other ideas? Any idea what the cost it at the dealership?

[killerbee]

Will a fan clutch be intermitant in engaging like that from day to day?

Not usually. It usually stays engaged full time, or dies completely. It sounds like maybe you have suffered coolant flow reduction. Water pump? Clogged radiator?

Can't rule out the clutch. When you spin it cold, does it spin free, or have some resistance? Should have some resistance (stops when your hand comes off it), turning it by hand. If it freewheels, it is dead.

[Kennedy]

I have yet to see one single instance where coolant flow was reduced on a Dmax or even a 6.5 when using OE radiator and coolant.

I would inspect the air side of the radiator. Also, pressure can be critical to prevent boiling. What cap did you use on your cooling system? Is it holding pressure?

[Mark Rinker]

I'd replace the cap, test the fan clutch, and de-bug the radiator/condensor/cooler stack. I had my raditor '02 boiled out last fall, and it was amazing how noticable the drop was on both engine and transmission temps, probably 10-15 degrees F cooler now under heavy tow conditions.

[CoachWagner]

I replaced the cap with an oem and the hose collapse problem is solved as well as strong pressure when hot.

The fan clutch does have resistance.

I have never had a coolant flush so the original coolant is in it. (no coolant loss) this morning.

I checked the air side (which i cleaned before I left) no major debris was found.

Maybe a flush and new dexcool would help? What is a "boil out"?

[killerbee]

Coach is it possible that you got false notifications? What was your ECT gauge reading when the DIC was warning?

[Mark Rinker]

I think the term 'boil out' is generic Minnesota venacular for taking the radiator to a shop that submerges it into a hot tank of solvent meant to loosen and remove scale or deposits inside the radiator.

[CoachWagner]

I was poking around the front of the truck and noticed something very odd. I think there is supposed to be a plastic piece that acts as an air dam in the holes of the bumper to force the air up to the rads. I don't have one the the plastic skirting is loose. I think at some point I must have hit something and it has fallen out the bottom. I can see how it would have attached up to the bottom of the rad and to the bottom of the bumper. Since it is now Sunday morning I think I will go to the home depot and cut some tin an bolt it in to where the factory piece would have been. I think this will help get more air up in the rad like the original plastic part should be.

[Duramaster]

Hey COACH. Didn't we talk about you cleaning out the radiator and CAC about a week ago or so? :confused: