Well. The interesting thing about a 140 diesel is that you can drop the 3 liter block into it should the engine go. They aren't too expensive. Last one I bought was $1500 shipped. It was used but had good compression.
The 140 teases you because you know it was possibly one of the finest cars engineered when you hear the the Maybach is built on it.
My 140 has been relatively trouble free. It needed some suspension repairs because I didn't drive it nicely, and a few things needed readjusting such as the vacuum pump and the door closing assist pump. That was just time to tune it right...
I have spent less money on my 140 than I have on my 126 sdl....
The evaporator was the big issue in the 140s. if that's been fixed, it's not really that bad of a car.

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All it takes for evil to prevail is for good men to stand by and do nothing.

Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic