Urgent W123 300D vacuum pump question
 

I'm trying to sell my 1983 300D, but I'm having an issue with a very loud noise from the vacuum pump. I parked the car exactly a year ago after the vacuum pump failed. It started making a very loud noise like an exhaust leak, and I lost vacuum. I didn't have time to deal with the car a year ago because I had a new baby. Now, I'm moving, so I want to sell the car. I looked under the hood and found that the housing of the vacuum pump had a huge hole in it! Wow! I took it off and put a new pump on this morning. I don't hear any of the grinding noise that people have described on here when the bearings are destroying your engine, and it runs fine after an oil change.

But, it's still making the very loud exhaust leak sound. Every stroke of the piston in the pump is extremely audible. Also, the oil pressure doesn't come down like it used to when the engine warms up. It used to come down to just above the 1 on the gauge, but now it only comes down to just under the 3. Is my hope that I avoided the worst effects of a vacuum pump in vain?

When the vacuum pump falls apart often pieces fall into the timing chain and gears throwing off the valve timing and pistons hit valves.

Sometimes when that happens it cracks the aluminum camshaft bearing towers and can bend valves and so on. Remove the valve cover and inspect the bearing towers and also look at the valves and so on.

Also, before you put the vacuum pump on what did the supposed to be smooth face of the timer that operates the valve pump look like?

Behind the timer is a thrust bearing. When there is too much end play that can ruin the vacuum pump. If you put a new vacuum pump on that can also get ruined because of too much end play.

See post 65 for a picture of the thrust bearing.

http://www.peachparts.com/shopforum/diesel-discussion/204187-what-particular-causes-vacuum-pump-failure-5.html

This is the whole discussion.
http://www.peachparts.com/shopforum/diesel-discussion/204187-what-particular-causes-vacuum-pump-failure.html