DD15 engine eating one gallon of oil for every 5000-6000 mile, Please advise.. :(

DD15 is different.
Engine can burn oil different ways. its possible that bad turbo will throw oil to exhaust or compressor side. but no way to send the oil to egr cooler on DD15.

 

Can't be a turbo. Is before the turbo.

 

He did What I know.

 

I found the issue. )

 

So what was it?

 

the information is classified.

 

Turbo exhaust side oil leak only on really low rpm. You can't even see it because go right away to the exhaust and burn out. Really low amount so usually people think it's a huge problem with an engine. Only issue is no idea that all. I have park heat so I don't idle

 

what is the mileage of your truck ?

 

800 000

 

Egr cooler gets cooled by coolant. If you do not have any outside leak. I would remove the cac tube on the turbo side and see. You can remove the S pipe at the turbo, start the motor and visually inspect it at idle, and at.higher rpms. If you are burning oil, your One box might get clogged.