just wondering what could be going on. i marked my degas bottle a few months ago. since then i've drove about 5-6K miles and it has dropped maybe 1/2 to 3/4 of an inch. the truck naturally runs below the fill line for some reason but i just wonder where it's going so slowly. the truck only has 62,000 miles on it and it does has a DPF delete with IDP tunes.
Any thoughts, and should i be concerned .
Thank you,
Chad

 

If you're loosing fluid from what is supposed to be a sealed, pressurized system, yes you should be concerned. If the system can't hold proper pressure the boiling point is reduced so you can overheat under towing loads, it can increase the chances of cavitation damage, if it's leaking into the cylinders it could hydrolock the engine if enough leaks in when it's not running, leaking coolant on the ground can poison small animals, and it just might lead to the collapse of global civilization. Seriously, you need to figure out where it is going and resolve the issue.

 

I know it could be a major problem but I honestly am lost. No drops on the ground, n no white smoke. But why would it be leaking so slow. I was very familiar with my 6.0 and the coolant issues but the 6.4 is a little gray for me. . How do you know if there is cavitation issues I know it happens but at 60000 ? That's pathetic if it is. I was thinking maybe an egr was leaking but my idp tubed should have that shut down. Then I thought about the heads but it would be showing around the degas bottle where it is puking it.
Anyone have an idea?

 

Have you been testing and maintaining the coolant nitrite level as specified in the owner's manual diesel supplement? If not that increases the chances of cavitation damamage. The most common place for that to occur is the back plate of the coolant pump, and when that happens you get oil and coolant mixing and making a heck of a mess.

The back cover was redesigned with an added anti cavitation tab to help eliminate the low pressure area prone to cavitation. This problem shows most commonly on 450 and 550 trucks since they have lower gearing and run at higher RPMs and thus higher coolant pump speeds, but it does happen to 250s and 350s as well.

Head gaskets seem to not be much of an issue on the 6.4, I've read a few cases of problems, but seemingly pretty infrequently. Other places coolant leaks have occurred is in the EGR coolers where the coolant gets dragged into the intake along with the exhaust gas and you don't generally see any visible signs if that is occurring other than loosing coolant.

The radiator hoses have O-ring seals that were prone to leaks and again if it's a small leak that's only appearing under pressure and flow that's when you're moving and you probably won't see much signs beyond some whire dried residue at the fittings. They redesigned those too and the new hoses have double O-rings.

You can always get some UV dye for coolant and run that for a bit and inspect with a UV light to see if there are external traces from a leak. A Blackstone report on an oil sample will tell you if coolant is getting into the oil, even if it's too little to notice on visual inspection. You can also look for oil in the coolant degas bottle since a leak will leak in both directions as the oil and coolant pressures change.

 

I had coolant disappearing, and it turned out to be the o-rings on the coolant hoses.
It was dripping on the engine I guess, and evaporating, leaving no smell, no marks, nothing to see what was happening.

You won't see it untill you pressurize the system and look around with a flashlight.


What the heck ever happened to rubber hose, and hose clamps? Worked too good and didn't need a dealer to fix, thats what.