Burning Oil

[SJPotter]

My 6.0 is burning about a quart of oil every 400 miles. I only have 40k miles on this rig. It's not smoking though and still has plenty of power (although the power doesn't kick quite like it used to at full boost, but it's still strong) I used to go between oil changes (3k miles) without burning a drop. I am wondering if this is related to an overheating incident that happened this summer. I was pulling a load up a long grade in Colorado with my new external oil cooler installed. This oil cooler is an after market product by a well respected manufacturer and it replaces the OEM oil cooler. It is an air cooler as opposed to a coolant based cooler. Anyways, I saw the oil temp rising and then peg at 255 for an extended period, maybe 6 minutes. The gauge stops at 255 so who knows how high it really got. I was running Rotella T6 and changed it right after this happened. It ran fine on the 1000 mile trip home and I have since had a new (stock) oil cooler put in. The temps all look fine now, and it runs good but I am burning oil, I guess it's burning because there are no leaks.

2 questions, What do you think is causing the oil loss, and is the overheating incident responsible?

Thanks in advance.

[mhatlen]

You might want to pull the ccv hose off and see if you are blowing oil out of that and also look into turbo for signs of oil on blades from it. I would see how much blow by is coming out of oil fill cap. This would be a common ring issue. It's possible that it got hot enough to raise hell with the piston rings, I would think a compression test should give you a idea if thats the problem. Is it smoking heavy under acceleration?