mechanic1

Yeah, did the new thermo when I flushed it and added new coolant. This morning while it was cold I checked the coolant in the rad and it was down a little.....burped a little more air over night must have. No leaks that I have found. Will drive it later on when I return the fan clutch tool and see if I get more air out of it.
To far...I'm in north Alabama.

mechanic1

OK, Radiator rodded out and back on...had some blockage, matbe 25% they said...Same result. Truck is running about 192-197 degree F empty.
With a new fan clutch, new thermo, new water-pump, new dodge coolant, Radiator checked and clean, About out of Idea's as to what it might be. Any suggestions would be greatly appreciated. Exhaust is the only thing left I haven't checked.
Hooked it to our camper yesterday evening and towed it around and up the local mountains here....197-201 temp, letting off of it to keep the EGT and coolant from getting to high. Radiator took about a good glass full of coolant this morning. So how long does it take adding to it to get it back completely full again? No leaks that I can detect. Head gasket has been in the back of my mind....but Still has good power and not losing a lot of coolant...expansion tank is still full or 1/2 inch from full. Idea's?

Dr.Dizzle

It seems as though all of the trapped air within the system was not relieved, it may take two to three warmup/cooldown cycles of adding coolant until the sysytem is full. That glass full of coolant may seem insignificant; however, it will make a difference. I suggest you top off both the radiator and expansion tank once again. Then hook up the trailer and observe your temperatures.

GAmes

Doesn't the '03s have a wobble valve to bleed the air out like the 12 valves?

mechanic1

??? Where are these wobble valves located at?

GAmes

On mine there is a small hose (1/4 inch, S shaped about 6 inches long) that goes from the front of the head, above the t-stat, to the neck that the upper radiator hose goes onto. The threaded device that it is attached to that is installed in the top of the head is the wobble valve.
Item #8

Dr.Dizzle

The third gens do not utilize the wobble valve/bypass style system as illustrated in the diagram. Instead the third gens use jiggle pins. A thermostat can either have jiggle pin(s) or a calibrated bleed hole in order to purge the system of air during a service fill procedure and subsequent engine operation. I believe the factory Cummins thermostat is equipped with two jiggle pins. Many of the thermostats available in auto parts stores contain one jiggle pin or a bleed hole. I would describe jiggle pins as brass rivets located on the flange of the thermostat. Given the reasons mentioned, I recommend a Cummins thermostat as a replacement. The quality and robust nature of replacement parts at chain stores seems to be hit and miss anymore.

From the service manual.

REFILLING COOLING SYSTEM - 5.9L DIESEL ENGINE
Clean cooling system prior to refilling

1. Close radiator drain plug.

CAUTION: Due to the use of the one-way check valve, the engine must not be operating when refilling the
cooling system.

NOTE: The diesel engine is equipped with two one-way check valves (jiggle pins). The check valves are
used as a servicing feature and will vent air when the system is being filled. Water pressure (or flow) will
hold the valves closed.

2. Fill the cooling system with a 50/50 mixture of distilled water and antifreeze.
3. Fill coolant reserve/overflow tank to the FULL mark.
4. Start and operate engine until thermostat opens. Upper radiator hose should be warm to touch.
5. If necessary, add 50/50 water and antifreeze mixture to the coolant reserve/overflow tank to maintain coolant
level. This level should be between the ADD and FULL marks. The level in the reserve/overflow tank may drop
below the ADD mark after three or four warm-up and cool-down cycles.

mechanic1

Yeah, both the old and the new thermo had two jiggle pins in them.
Drained about two gals. of coolant this morning and ran the engine till it warmed up....with coolant near the top of the Rad...Had very, very small bubbles coming out of the flews in the rad below the coolant level. I don't know if that is a "normal codition with out the cap on the rad and no pressure on the system or I have bigger problems. I would estimate the bubbles to be not hardly as large as a straight pin shank in dia. but a few of them. What do you think?

mechanic1

Ok folks, I'm about out of idea's. Pressure tested the Radiator and coolant system and the Rad. cap. The Cap is rated for 16 psi. and would only hold about 13.5 psi. so I changed it with a new one...no change. The system held 20 psi at operating temp for about 5 min. and then started to slowly drop off as expected due to the engine and coolant cooling down. I did run the engine for a good 20 min. to warm it up with the pressure tester on the radiator and didn't notice any strange needle movement as it might with a blown head gasket.
Checked the turbo....moves freely enough...

This is what I have done to it so far....new: fan clutch, new thermo, flushed and new coolant, new water pump, Radiator cleaned out internal and external, new air filter, new fuel filter, oil change(cause it was due) and filter.
removed the heater hose to "burp" the system.
It runs about 188-192 F most of the time but under acceleration load it will go as high as 204 F. And the EGT's seem to come up a lot quicker lately. I also took it to a buddy of mine's muffler shop and we did a back pressure test on it...no matter how hard I gouged on it, it never got over 3 psi.
Truck has an Edge W/attitude but I almost never run it up more than stock or the mileage setting. So, If anyone has any idea's what the heck is going on please let me know. I'm sure that towing something I won't get to far before it is getting to hot.

GAmes

Is your new fan clutch an OEM or a rebuild from a parts store? Does it roar like a jet plane when it engages? I had an overheating issue and did the same things, finally bought a fan clutch fom Dodge and coolant overheating went away. EGTs are an entirely different matter so don't try to link the two. I can easily get high egts without overheating the engine, and before the fan clutch I would have normal egts while the coolant temp was climbing.

mechanic1

.....fan clutch new from Dodge in stalled from the dealer.....And yes, at times it sounds like it is sweeping the road.lol No more codes....believe it is working properly.

Bark

Probably not your problem but had a similar experience with my old Chevy. After warming it up without the rad cap on I used a dig thermometer in the fluid and an IR thermometer aimed at a freeze plug and discovered that it wasn’t over heating. It was a bad gauge sending unit that was off by about 20f. Don’t know if that can happen with our computerized set up but its just a thought.

mechanic1

Checking the coolant sensor next.lol

snowmanx

I just got a new engine put in my truck and it runs about 190* unloaded, will go up to 200* under hard, long acceleration it goes up to 200*. With a loaded 9000# 5th wheeler through the mountains goes up to 205-210, but will drop back down to 190* when back to cruising speed.

Like madhat first said, doesn't really seem all that bad, but I dont' know much, just hoping that;s the case with my rig.