I have a 05 6.0l that started over heating while towing recently. In 2012 i did egr delete, oil cooler, stc fitting, and coolant filter. I recently changed radiator and tstat think that was the problem due to small leak in radiator, but still towing about a 4-5k load temps rise to over heat while towing. Any help whould be great as to what to look for next. Also fan seems to be work properly I monitor fan speed eot ect and tft on my scangauge.

 

how high did your temps get? engine fan come on?

 

What are the actual Temps you are seeing?
When you say over heat is it defueling, shutting down, loosing coolant?

 

What brand of radiator did you put in?



Sean <BR>

6.0L Tech Folder

 

Is this an original plastic impeller water pump?
Is the coolant system building pressure, any puking? What are your temps?

 

Temps got up to 232 ect. Fan seems to be coming on i can hear it. Normal driving ect at 191-193. Towing 206-209. Its when i go up and incline or put a load on engine. Once it hits 220 it pukes out degas bottle. I have the mishi radiator. And yes i have plastic impeller water pump

 

I never lost power or defueled. I let off as soon as i saw temp hit 220

 

Need to replace cap, tee in a pressure gauge to watch in cab going up a hill loaded, see also what temp oils getting on same hill. Do you have head studs already?

 

On a properly functioning engine, EXT should not get over around 225 because that big fan will cool it back down when the fan clutch is locked at 220.

You still have your egr cooler? The puking combined with the temps suggests egr cooler rupture or HGs.

I've got a clean cooling system and about 5k miles on a new oil cooler. Towing 70 to 75 mph on a 32', 9k lb TT, my deltas are less than 15 degrees. My deltas on initial air temp and intake air temp is around 45 degrees.

Of your deltas are high, it suggests oil cooler problems.... Which suggests ruptured egr cooler.

 

The cap was replaced in 2012 when i did the egr delete and oil cooler. No i do not have studs. If heads were bad wouldn't I notice lost of coolant. White smoke or milky oil or even lose of power and truck running bad?

 

The deltas in eot and ect and within 10 degrees or less so i dont think i have an oil cooler problem

 

Due to the high compression and high combustion chamber pressures in the 6.0 you will usually not see the normal signs of head gasket failure like you will in a gas engine, the sure sign of a head gasket failure in a 6.0l is coolant puking from the degas bottle under load but you need to make sure your coolant level isn't above the minimum mark on the degas bottle on a cold engine and replace the degas cap and test it again to see if you still puke coolant.

 

What coolant are you using? How many miles on it? Or was before loss/puke? What does it smell like - any diesel smell in coolant?

 

I thought you said it puked when you towed? Isn't that loss of coolant?

HG failure in a 6.0 can be quite different than gasers or even other diesels. In a 6.0 it can be very suttle and not lead to oil and coolant milkshakes.

Rule out everything else before concluding HGs, though. Make sure the coolant level is 4" below the top. If it's too high, it will puke on a properly running truck.

I would pressure check my coolant system and see if I get leaks. Use a loaner pressure tester from an auto parts store. If that passes, the HGs can still be compromised. I'm guessing it'll pass the static coolant system pressure check.

Next step is doing a dynamic pressure checking of the coolant system. This entails running a small tube and gauge T'd into the degass tank line. I've run mine below the hood ( on the crack between the fender and grill), over the mirror, and through the window. You can hang it off the mirror and still see the gauge. Lots of writeups on it.

With your egr cooler deleted. Warm up the truck and watch the pressure gauge. Get on it a few times. Fast pressure fluctuations or excessive pressure indicates a compromised HG leaking into the coolant system. Because you have an egr delete, the excessive pressure (other than normal pressure from heating) can only come from cylinder compression.

Operating pressure on mine is around 11 to 12 psi. System is rated for up to 16 psi. I found my weak heater core when I pushed mine to 16 psi doing a static test.

If this is inconclusive, warm it up to temp and release the coolant system pressure by removing the degass cap. Yeah, don't get burned. Reinstall the cap and run some more. Get on it good. The pressure should not rise more than 1 to 2 psi after releasing the pressure.

If this is inconclusive, you may need to do the same Testing under the same conditions your getting the elevated temps--ie, towing. The head bolts may need to stretch a little to slightly lift the heads to recreate the issue. If you don't see excessive pressure or fast fluctuation in coolant system pressure after all that, I'd say it's not related to HGs.

I had an elevated oil temp issue and a deleted egr cooler. It was only after doing the above that I safely ruled out HGs.

 

Coolant is GO-5. Has about 2000 miles on it. It only puked when temps went above 220-225 shouldn't it puke when it over heats? As soon as i can get my hands on the stuff needed to pressure test i will