I have a 2004.5 they tell me...325 hp. 5.9 HO. About three weeks ago while towing a trailer that weight about 5000 lbs. thru KY. It started having elevated engine temps. to the tune of 197-206F....never did that before so I flushed the coolant system, changed the thermo but it didn't help my problem any so off to the dealer I go...sure enough, fan speed code as I suspected. New fan clutch and $$$ lighter the truck is fine, running like before again and all is well, but now, about two weeks later the problem has returned. The truck is stock other than an edge with attitude I put on it about 6 months ago. I never run it in anything but stock or mileage option however. Never had a problem until now.
...Checked for corroded wiring connectors as one member suggested, including the ECM connecters....nothing changed. Anybody have any suggestions?

 

How's your tranny fluid? How about the rad, is it clean on the outside?

 

Sorry, left out the tranny info.....NV5600 6sd. Haven't checked it in the past couple of months but has no leaky wet seals. I do need to change all the gear lube in the running gear though.
the Rad I have hosed it out along with the condenser and cooler...appears open enough to me....the inside of the core at the cap, what I can see doesn't appear to have any corrosion in it.
Wondering about the waterpump now. Anybody have any problems with them?
Also wondering if the air filter might cause this situation or partially clogged exhaust? Truck still has good power though.
Going to put a new air and fuel filter in it this morning anyway and see.

 

Those temps don't really seem that bad, if you were pulling though mountains or something.

Usually when a water pump starts to go, you notice it leaking at the weep holes. Not always the case, but common. Mine went at 75k-ish, got it replaced under warranty. How is your heat? If the impeller is starting to take a poo, it won't heat the truck as well.

Tranny does not have anything to do with it if it is a hand shaker.

If you still have a cat on it, it could be clogged, but if your power is still good, more than likely you're fine. They normally don't go bad unless you have a lot of power adders/bad fuel.

How many miles on the truck?

 

I agree with madhat. When the coolant was flushed did you pull the high point threaded plug in the head during the procedure? If not, you may have an air lock in the system, causing the slight elevation in temperatue.

Do you have sufficient heat at the vents? If not, this is indicative of air trapped within the system. It may be a matter of an air pocket in the head. I suggest you unthread the plug until you get a constant flow of coolant out. Run the engine with the cap off until the thermostat open up, then top off your coolant.

 

Having an air pocket trapped was going to be my next point, I just ran out of time this morning.

When you are flushing your rad and re-filling it, (I know you did not do this, the dealership did), you need to make sure that the t-stat opens and you get fluid through out the whole system, or an air pocket will cause irregular pressure, causing coolant to boil in areas. (something like that.)

I did not pull the pull the water plug in my head like the Dr said, rather, got the truck up to temp and then left the cap off and watched the coolant flow, and added until it was to the top and flowing well (t-stat open). Then I topped it off at the rad, then added it in the over flow tank.

 

The truck has 232,000 miles on it. ran it up to temp with the cap off this morning to check for circulation. I didn't really see a lot of activity in the way of coolant flowing around as best I could see. The upper radiator hose did get quite warm to hot at about 190 to 192.
I did do the flush myself and refill with new dodge coolant though prior to having the new clutch fan install. The problem went away or it seemed for about 10 days...was sure the fan had went again but it seems to be acting right and hasn't thrown any codes.
I'm plan on draining the coolant out and pulling the radiator to check it for external blockage just to be sure.
Talked to the dodge diesel guy at the dealer that installed the fan clutch and got some suggestions.... checking the waterpump for wear among those.

 

How about the rad, is it clean on the outside? This is an extremely good question, that needs to be answered yes or no. On my 00, I had a leaking front main seal for years, and the average temp was slowly increasing. When I pulled the rad and coolers to fix the main seal. I noticed that the rad was badly plugged with oily grease. I had pressure washed the rad about a year previous, and it did nothing to help. With the rad and coolers removed and seperated, I was able to degrease and pressure wash (dont get too close) the crud out of the cooling fins, BIG DIFFERENCE!, problem solved.

 

...working on getting the Rad out now...

 

When mine started elevating the temp on a pull, I got out the mirror and sure enough the water pump was leaking slightly at the weep hole. Only takes about 30 minutes to change it out. A little light grease on the o ring will hold it in place when replacing the pump. Also you do not need to remove the radiator cap, just loosen it to the first notch so it wont build pressure. That way you wont have coolant all over the place. Autozone is a great place for a new pump, as they are new and not rebuilt, therefore no core charge and you can keep the old one for an emergency. $55 out the door.

 

If you feel the need to utilize grease on the o-ring, I recommend placing some waterproof /silicone grease (plumbers grease) on the o-ring to facilitate the installation. This can be found at hardware stores.

Do not recommend the use of petroleum based grease or lubricants on the o-rings. This practice may compromise the integrity of the material, therefore causing the o-ring to swell and eventual failure.

 

New waterpump for a 5.9 HO is only 55.00? How many miles you got on it? It working out good for you? Sure wouldn't mind putting a new one on since it has so many miles on it and I already got the Rad out of the way.

 

Ok, got the rad off and started by using some Simple Green cleaner on it via the air-siphon rig I have. Put thr garden hose on it back flushing it thru the fins and flutes...Amazing how much crap came out of it and it didn't even look that bad to me.lol Mostly just a lot of bug pieces that looked like would disturb the flow of air thru the rad. Wasn't satisfied with the results so I loaded it up and went off to the local car wash and pressure soaped and rinsed again from the back side...much better now. Should be flowing good now. Thanks for the tip.

 

OK, truck is back together...new water-pump, washed out the rad., Still running a little higher than normal temp. I did have trouble getting it to take all the coolant back in though...until I removed the heater hose from the tube sticking up out of the heat....got a lot of air out of it! Any chance there is still more in there? Anyone know of a better way that will get it all out if any is still in there? Temps. running up to 200...no load such as a trailer or camper....not good.

 

Yeah, there could be.

Have you thought about the t stat?

Where do you live? If you're close enough, come on. I'll fix it.