So here is a relatively new (or at least becoming more noticable...) issue-

When starting the van cold; it turns over and starts great. The low oil pressure light stays on for 3-5ish seconds. This is a new thing, I think. It also burns oil for about a minute. If within that minute (plus or minus) I rev the engine, a blue/white smoke comes out the exhaust pipe. The engine overall also sounds a little louder/less smooth than it usually does (which I think may be typical for diesels?). Once she warms up, no blue/white smoke, the engine runs very smooth...and we are off.

I am thinking it may be a one (or a combination) of a number of things:

-Worn valve guides are letting a bit of oil seep in the combustion chamber, which gets burnt off as it warms up?

-Turbo is going? I would think it would burn oil (visibly) all of the time though....

-Worn piston rings? (it is 25 years old.....)

-cracked/broken piston?

Any other thoughts?
Thanks!

Matt