new owner
 

I am the proud new owner of a 1987 300sdl, it is in good shape but for a few dings & the front seat bottoms need recovered & all the power accessories work except the sun roof it shows 195000 but the odometer does not work so no tell what actual mileage is run & drives but for some clunking noise when going over bumps. what items should I check before I start driving it on a regular basis? I have been a diesel mechanic for 40 years but never on Mercedes.Any help will be appreciated
Thanks DD

check suspension and steering (the clunking is probably the upper ball joints-easiest to replace the whole upper control arm, check the lower ball joints too; they're probably ok though); check tie-rods and the flex discs on the driveshaft. engine-wise you probably know what to look for

May be time for a suspension rebuild. Pretty straight forward job:).

does the engine have any quirks or items that need to be replaced at high mileage

vacuum pump is a weak spot on the motor, as is the belt tensioner, and the timing cover that it bolts to. also, the engine needs a fully functioning cooling system, as even a slight overheat can pop the weak #14 original head.
this motor uses a long timing chain, so inspecting for stretch and either replacing the chain, or installing an offset key on the cam to correct the cam timing, then adjust the IP timing for best combustion.
I'm sure there are other issues to look out for as well. delivery valve seals, climate control failure, catalytic converter gets plugged, egr soots up the crossover tube etc...

On the W126, the most likely source of clunking from the front end are Guide Rod Mount Bushings. The sound will come from under your feet.

What the man said except MB doesn't offer an offset key for the 603.

By 200K miles many of the original injector line clips and shims are long gone. Lines rattle and break when not properly restrained.

Sixto
87 300D