Looking for someone with more experience then me to confirm the conclusion I have come to or point me in the right direction to find the real problem.
I have a 99.5 F250 with 160K miles. 25K miles ago I had cracked pistons I put in new standard sized pistons and rings. At the time it got new gaskets and O-rings all around including injector O-rings. The heads were sent to a machine shop and rebuilt as well. The truck has been running great since then.
A couple of weeks ago I went and did something that if my suspicious are correct was down right stupid.
Like many diesel owners I got the itch to modify and since I had success with the previous problem I decided to "tweak" my turbo. What I did was I did the EBPV delete to include a new pedestal I also put in an ATS ported compressor shroud to solve a surging problem.
I wasn't satisfied with just solving the problem I thought it was a great Idea to also put a WW in it as well to see if I could really make that turbo scream. (and boy does it ever) In doing this I noticed a drop in boost about 1 psi. So I started messing with the two impellers; stock and WW. To see just how they would work one verses the other. Along the way I also decided to put in a Turbomaster waste gate actuator. I ended up pulling the turbo out and swapping the impellers 4 times. The last time I put it back together I had the stock impeller in it since I liked how that set up worked.
The first time I started the truck and then turned it off I heard a metal on metal "tinking" sound. It was the impeller hitting the compressor housing. I checked and found some play in the shaft. At the time I thought by messing around with the turbo I have gone and messed it up. Oh well I thought here is a good reason to do it right from the start and have the turbo rebuilt by a pro and have them put a WWII on it and balance it up nice and proper. Since the WW didn't hit the housing I put it back in making 5th time the turbo was pulled and impeller swapped.
Since I didn't have the money to do it right then I thought I would drive it for a while. As I always do before any trip over 50 miles I checked the oil and noticed it was about 1 1/2 qts. low. I thought nothing of it at the time. The next time I checked it I found it 3 qts low. I am burning about a qt of oil every 100 miles. I say burning because there is no evidence of an external oil leak. It has the customary blow by a 7.3 of it's age would have and I have some white smoke at idle. Also I have no loss of power.
Tomorrow I am going to pull an intercooler tube to see if I have any oil in it. I say any because I did the crank case vent mod a year ago and there should be no oil in the tubes.
My guess is the leak is in the turbo and I need a new or rebuilt one ASAP!!!! I am open to suggestions. Also I have access to an Auto Ingenuity scan tool. IF anyone thinks that will help diagnosing the problem. Thanks in advance.