PeachParts Mercedes-Benz Forum - View Single Post

LUVMBDiesels · #11 03-28-2009, 12:31 PM

On both W126's

#1 RUST! Look around the plastic cladding, the rear wheel arches, jack points, and around the rear window

#2 Front suspension. Depending on the mileage you could need control arms, ball joints, tie rods and ends, center link, and the steering damper (the shock absorber that attaches to the center link. These parts could run you $700.
If you need shocks, go with the Bilstein HD series.

#3 Accessories like power windows (easy fix) sun roof (harder fix) and power door locks (vacuum operated with a pump in the trunk-- class act)

#4 Climate control The over complicated automatic climate control will probably not work. Check the engagement of the compressor and the activation of the various vents. The compressor should engage in all positions except for "ec"

#5 Coolant The coolant should be a straw color not green or orange. MB recommends using either their coolant or Zerex G-05 as these have the proper additives and are ph balanced neutral.

#6 Service records In both cases service records are important, you want to know when things were done.

420 SEL -- not having much experience with this car I will not comment on the engine except that it is a little small for the car. The performance wil be about the same as in the 300SDL. The guide rails, timing chain, and water pump should all be replaced.

300SDL -- check to make sure it is not overheating. Run the car and see if the temperature guage goes up past 80. If it is runnning hot you could still be alreight, but if the gauge goes up to 120 the engine is most likely no good. The SDL had a weak cylinder head with a casting number of 14. Look between the 2nd and 3rd intake runner and you will see the casting number. My #14 head has gone over 306000 miles but the car has never overheated. If it overheats the head cracks! Check for records. The timimg chain, vacuum pump, water pump and serpentine belt should have been replaced no later than 150000.

Both cars are very fun to drive the W126 does not feel like a big car on the road, especially like a big 1980's luxo-barge (Buick or Lincoln) They love to go fast and do it in style.The longer wheelbase cars are my favorite so you cannot go wrong with either choice.

Good luck and have fun!