An earlier post on feed pipe nut torque went a bit off topic, so I'm starting a new thread on tail pipe smoke on a '01 LB7. After posting my BR and PW numbers, it began to appear that my injectors weren't in as bad of shape as I may have thought- despite the heavy smell of diesel which still is in my exhaust and the truck still smokes with greater frequency. There was a suggestion that my smoke may be related to something other than injectors.

A few months back, at around 340K miles, I had a set of head gaskets replaced and the heads were machined, with new valve guides and a valve job performed by a local performance shop. My local dealership did the balance of the work. I am now noticing that my oil level appears to be dropping- between a half to a full quart in ~600 miles (nearly all of which is highway miles @ about 60mph). I'll check the level immediately after allowing the engine to idle for a couple of minutes, then notice the oil level being down ~1-2 squares on the dipper. I'll add nearly a qt of Rotella T6 synth and check the level again immediately after allowing the engine to run for a couple of minutes- all better, until a week later. The last 2 weeks now, I've noticed the oil level as being low. In better than 300K miles (previous to the head gasket job), I've NEVER added oil beyond a filter change at 4K and an oil/filter change at 8K.

Do I have oil seeping past the valve guides? Oil leaking into the manifold? This appears to be way more oil consumption than I've had ever and quite possibly the source of my tail pipe smoke!

Comments?