Boy this is a long and old thread and I wonder if anyone even still follows it. I am getting long in the tooth just like my old diesels. Mercedes is a pale shadow of its former self and all the newer german cars are notorious money pits of absurd and unnecessary complexity. As a mechanic I would avoid all diesels after 1985 . The flaw which doomed them was combining a steel block with an aluminum head. The differential expansion of the two metals caused head gasket failures and this happened to many manufacturers who went that route. It took a long time before the engineers managed to ameliorate that design flaw but it was a stupid idea then and now. All steel engines like most diesels will last and last as will many all aluminum engines. I have 2 82-85 sedans and one 84 wagon and a parts car. We still drive them all in the summer here in snowy wyoming. I had an 87 sdl which was a blast to drive but finally sold it when I started seeing head gasket failures. Our daily drivers are all Toyotas, 2 1998's and one 08 and they are the epitome of reliability and repairability and they all have over 250000 miles just like our MB diesels.

I have fabulous father and son mechanics. The Dad has been working on Mercedes only since 1960.

Greta, the ‘92 300D visits his shop twice a year. He does what ever is needed.

I do fluid changes all the time.

He fully expects me to drive it for another 30 years.

DB444 nmakes a lot of excellent points about all manner of issues and as an experienced amateur MB mechanic I agree except for one of his opinions. It is simple and relatively cheap(less than $100) to rebuild the turbos if is the issues are the bearings or vanes which they usually are. I did mine in a few hrs in and out a few years back and went from 5 psi boost back to stock of about 11. I even found a brand new(!!) in the box turbo in France a few years back for $400 shipped. Very dusty box but mint condition of course. There are lots of reasons to move on to other cars like Toyota/Lexus for your daily drivers. My favorite car is still my 84 300TD wagon. Got rid of the self leveling suspension and replaced the damn power windows with roll ups. zero rust and dents and it always attracts a crowd unlike the sedans. In the 70s-80's MBZ was the hands down best of the best but that rodeo is over. The high cost of diesel and diminishing parts availability just adds to the problem. I'm keeping the old diesels in case we get a solar flare or political EMP and in a pinch I could use veggie oil/#2 diesel mix if I had to but veggie oil was dumb idea that ruined a great engine. Diesel is the fuel that will become scarce and expensive way before gasoline which is why I have moved on and over to older Toyotas which are the current gold standard IMO.