Ram 2500 Cummins 5.9L losing motor oil & Turbo or Transmission problem?

Howdy. I'm somewhat new to the diesel ownership thing. Bought a 2005 Ram 2500 (automatic transmission) with 184,000 miles on it. Previous owner said he replaced the Fuel Injectors and Glow Plugs at about 173,000 miles at the suggestion of a diesel shop. He thinks it made it perform better. Not sure if that was necessary but my gain. It's not a High Output model that I'm aware of (seen some 2004s with HO on them). It's all stock equipment on it.

I replaced the fuel filter (it was dirty, farm fuel truck) and changed the motor oil/filter and transmission fluid/filter. I've put almost 4,000 around-town miles on it since. Mostly below 45mph on dirt or local roads. I never tow with it, and previous owner said he used it to tow his 4 horse trailer to ride sometime.

I've noticed when cold (as in Summer/mild temps) the truck doesn't want to move Forward or Reverse when I initially give it considerable pedal. It just sits there and spins up, but seems to be restricted because the RPMs don't ping up as much as I'd think it would if in Neutral or Park. It blows some black smoke, but not a lot, which I gather is non-burnt fuel. This is the same whether I put it in 1st or in Drive. However, after it's warmed up for about 2 minutes it goes Reverse just fine, however to make it go forward at a reasonable rate of speed I have to manually put the selector in 1st and then Drive after I'm moving. If I put it in Drive (after warm) it's still unresponsive more than it should be, but not as badly as when cold. What are the likely causes of this?

Turbo failing? Transmission solenoid(s) failing? My buddy seems to think it is a transmission solenoid responsible for shifting from standstill to 1st-2nd gear. Because when I manually put it in 1st it operates more normally (at least after it's warmed up). So currently when I drive it and come to a complete stop, like at a light or stop sign, I shift it to 1st and then toss it to Drive after I'm at 10-15mph. It works fine after I'm moving and is spunky when I stomp the pedal for highway speeds acceleration.

When I changed the transmission fluid and filter, I noticed some shavings on the pan magnet, but no more than normal for a vehicle that was run 40,000+ miles since the last change (if not longer, previous owner wasn't sure if it's ever been changed from his answer). Since I've changed the fluid, the fluid looks good, doesn't smell burnt, nor is it losing any.

Second problem is I'm losing motor oil somewhere and don't know why. I don't see any physical leaks. It holds 12qts. Since changing it has lost 3.5qts total over the 4,000 miles. I noticed the first 2 qts about 3,000 miles after the oil change. Then another 1.5qts after another 700 miles (after I refilled the previous 2qts). It's not blowing white smoke that I can see, and only blows a little black smoke when it's cold and doesn't want to go Reverse or Forward in 1st (ad described above). It blows considerably more black smoke if I put it in Drive and try to make it go when cold.

Any ideas where to start? Are there any computer diagnostics that will tell me hints? I don't have a check engine light on anywhere or any other warning lights and the oil pressure and temperature gauges are reading good also.

Thanks for your suggestions!

I believe if the transmission filter is installed incorrectly it can cause a delay when shifting into gear. Not sure if it will cause what you are describing.

If you are losing that much oil and no leaks its most likely being burned off by the turbo. Being a diesel you probably wont notice any oil smoke like you would if you were consuming that much oil in a gasser.

Sorry im not much more help than that, but im sure someone with more cummins experience will be along soon!