Bad mechanic???

dont those detroits havesmall rubber seals around the oil galley holes that if you dont install them correctly when doing head job they can fall out and cause the oil to leak into cylinder between head and block? i dont rememeber if it was my detroit or my 3406E that had this issue after. Did they use your same head? it could also be that your burning the oil thru the valve guides in the head as well if they are worn and werent R&R when the head was off then you have a new headgaskets with a used old head with close to 1 mill on it...and no R&R.

if you did an inframe i know of people who say it will burn oil till the rings seat....another crap excuse IMO, but thats not the case here cause all you did was the head job.

 

With almost a million miles, and the OP not telling us what has also been done or not done to the engine in that million miles other than the head gasket, all sorts of other things may cause oil consumption.

 

if he made mistake it would have showed up pretty quick.mine has 948000 gallon every 15,000 but that is big change make sure no fuel in oil to dilute it,check turbo,did it happen quickly or over time get worse

 

thats exactly what i was going to say as stated in above post, it doesnt matter what other wear the truck has, it went from using no oil to burning 3 gallons every 15k wowsers..

 

Dirt into the cylinders when the block was being cleaned, not wiped out, now liner walls and rings are scored and burning oil. Confirm with a blow by test.

 

I don't do Detroits but there is no possible way that overhead will cause an increase in oil consumption. I have heard as well as one of the other comments that Detroit has oil seals on the head gasket such as CAT that could cause a problem. You may first see if there if a lot of dampness on back side of turbo. This should lead to pulling exhaust manifold and see if there is a particular cylinder dumping/burning oil. It may also lead to a workmanship fault when the head is pulled to see if the seal was left out.

 

I think the seals you are thinking about are the special washers that go on some of the cam cap bolts, yes/no? Oil will flow through the hole for either the cam shaft, or supply to the jake housings. If the washer is missing you will get a general loss of oil pressure, but not a consumption problem.