Hi..I think I just seized my 81 300D...the love of my life...how can I tell for sure...no mercedes or diesel mechanics in our town...might just sell for parts ...any ideas???

 

It seems to me that saying anything beyond, "I'm so terribly sorry, " would be trite.

What were the symtoms prior to seizing? Did it have a normal oil pressure? Did it run hot? Have you ever had problems with the starter or battery? Is the oil on the dipstick within normal limits? Is the color a normal deep black or is it discolored with streaks of brown/gray?
Does your AC work? If all of the above are ok, your compressor could be seized and not your engine. Check it by either removing or cutting off the compressor belt.

It could also be a massive vacuum pump failure which can spew bits of metal into the engine.

On the other hand it could be a simple 2 part problem: A transmission glitch, coupled to a loose vacuum hose.. That is, the engine will only start in the neutral position. The other problem has nothing to do with it not starting, but with not shutting down: It's probably a loose hose or the vacuum pump has given up the ghost.

 

Thanks so much,,my gut feeling is that the vacuum pump has done something bad...The highway ride prior to this was amazing as far as performance and the oil was good before and after,,pressure and temp awesome and I was still able to pass at 100 (km) like I mentioned, when I exit the highway, the brakes felt very hard...I had already arranged to have the vacuum pump rebuilt because it had been rattling for a few weeks...thanks for your knowledge...I'll check out your suggestions.

 

I strongly suspect that many of us, when a problem arises, very often think the worse . I know I've certainly done that a time or two.. I know it's a tramatic time for you, but I hope you'll hold onto the possibility that your problem may not signal the end of your beautiful old auto.
It seems to me that it could still be a 2 part problem. That is the vacuum pump could have died without spitting metal into the engine, which may account for the brake symtoms, while as the same time the compressor seized up. When you slowed to exit the freeway, perhaps the engines slower revs were no longer able to overcome an utterly failed compressor....

So hold on a bit more while you continued to look at all of the possibilities. I'm nearly totally convinced that by far the best info on the net is with Schuman Automotive. Henry Schuman has been a Mercedes diesel mechanic since 1977. Unlike many at the Mercedes club, Henry's never uppity, is always patient and believes the only stupid question is an unasked question. I truly trust Henry, et al. If you are a member of his forum he will also sell you parts at deep discount. It seems to me that a large number of very experienced diesel mechanics hang out at Henry's fora and they all seem to have a very deep understanding of their craft and are eager to share it with anyone who asks.