My engine hasn't had the easiest life, that's a given, and I'm at 480K. Still seems to have most of the HP's is did, and is getting really good mileage, managed 18.1 combined last time I checked, but man, is it pumping a lot of oil out of the breather. I have a billet tappet cover with dual breathers and I made an oil stripper catch can, and it fills up quickly so I just leave the drain open.
Bought a pan evac thingamajig like we used on the drag cars to suck a vacuum in the crank case, thinking about trying that to see if the issue is ring flutter due to wear. I also bought a can of the original formula of Bon Ami that Caterpillar used to sell for re-seating rings, might try that as a last resort. When I pulled the head for studs at 300k I could still see cross hatching...maybe the rungs are just gunked up and need a Baryman's "Italian tuneup".

 

Have you checked really well for any vacuum leaks?

 

No, brakes and vacuum HVAC controls are working. I would imagine the old vacuum pump is a bit tired though.

 

Even if the HVAC system and the brakes are still working, you could still have a major vacuum leak.
Pictures broken rubber hose, split elbow, unplugged lines, bad booster.

The vacuum the pump makes is by sucking in air, that then needs to be vented from the motor.

You could very easily just have a leaking system. It would be the first thing I would check before buying any other parts.

 

Hmmm. So are you saying the vacuum pump exhaust is into the crank case? Guess I never thought about that if that is the case.

 

Yes it dumps exhaust into the timing case that dumps right into the oil pan, making "blow by".

 

Learn something new every day, thanks.