I'm pretty sure mine needs to be replaced or serviced. I don't have the $800 to get it done right now. How much harm am I doing if I don't get it done right away?

I have all the signs, smoke out of the dipstick, burning oil smell, etc...

 

It's causing a pressure backup in the engine. This could possibly cause the rear main seal to blow. I just helped my son in law do one the other day. The parts are around $120 and the time is at most four hours, so where does the $800 come from? I could see $500 at the most. Buy the kit from fcpgroton and then find a decent mechanic to do the work might be an alternative. I would bet my son in law would do one for somebody for about $300 labor, so that would be around $420 complete job.

 

I just ordered the kit for mine. Second time my system is backing up, the first was more expensive as in the rear main seal did blow (had a local shop do the repair for 1k).
I've parked my 97 850 until the kit arrives and I install it (don't want to risk blowing another rear main seal).