'90 300E 4matic:

I've noticed an increase in oil consumption recently, as well as a noticeable puff of white exhaust when engine is pressed hard on highway. Don't see any unless really pressing accelerator.

The oil is something i check regularly, at most gas fillups, and was normal only a few weeks ago. Now it's at the low dipstick mark and even the dash warning light flickered on / off.

Any thoughts?