DIFFERENCES
 

what are the main differences in all the w140s made throughout the years it was produced?

I have had a '95 and '98 S420 and currently drive a '99 S500. I am not a DIY mechanic so I use the dealer until I can find another independent shop in the Cape Canaveral area.


Off of the top of my head;


All of them suffer issues with the pneumatic locking system. This system also affects the AC vents in the dash along with the auto climate control stuff.


All of them require suspension work at some point. Bearings, bushings, ect. I think that the V8 and V12 models stress the suspension more so expect $2k-$3k of suspension work over a 5 year period of ownership.
The S500 and S600s had the hydraulic shocks on the rear which are very expensive to rebuild/replace. Mercedes quoted me $2800 for new struts and $2100 for rebuilt. I think all models could have the self leveling option which is also very expensive to fix so I would ovoid those cars. $6k-$8k for all four corners and they ALL start leaking at 100-120k miles from what I have been told at the dealer and have seen myself.


1995 and older W140s had HVAC Issues that could be very expensive to fix. It is under the dash and requires removal of the airbags so a multi $1000 event. This is supposed to have been fixed with the '96 and newer models.


Older 140s had issues with the wiring harnesses. I never had to deal with this one but apparently the harness gets brittle and needs replaced. I am not sure what year models this gets better.


1995 and older had 4 speed automatics. 1996 had the 5 speed automatic.


S320 and S420 had the option for a long wheel base or a short wheel base.


The W140 cars are very nice to drive and probably one of the safest cars on the planet but very expensive to maintain over time. I think that it is safe to say that if you pay $10k for one, you will spend another $10k over 5 years or so. It is wise to spend a little more up front for a really cherry car. The interior is very expensive to repair and parts are difficult so pay attention to the leather and the wood. It seems like the engines and transmissions are bullet proof but all of the other stuff will crush your pocket book. When people say that the Germans over engineer everything....this is the car they are talking about!

I have to say the pre 1995s have better leather.But the pre 1995s have issues with wiring harness,unless it was changed.My 1999 I have had 5 years and I've only spent $1500 in parts.Of which $710 was not needed.Learn to do your own labor.If you have to use dealer things can get expensive.Things I replaced was coils,wires,plugs,ignition switch,k38 relay,idler pulley,belt,transmission service twice,and a starter.Now my nitrous kit is included in the cost $250. It makes the 6 cylinder fast,faster than a s500.