1998 W140 Probelm Areas
 

Friends -

There is a 1998 S320 for sale here at work I am really intrigued by - 71K, all records by MB shop, immaculate. Here's the deal - some expensive maintenance has been done (closing assist pump, blower motor, propellor shaft) along with regular wear items, BUT neither the wiring harness nor the evaporator have been replaced.

Wouldn't it be prudent to assume these items will require replacement, given the history of the model, and factor that into pricing decisions?

THANKS for thoughts

Brian
1989 300TE 275K sitting
1992 300TE 165K running

Wiring harnesses were fine after 1995, so that won't be a problem.

I'm not sure if the a/c evaporators were ever fixed. They are all going to fail eventually.

I have a 1999 model S320 and all of those issues were resolved in the final revisions of the car. If you are looking for a strong and reliable 140 a 98 or later car would be your best bet. The earlier models while supposedly better quality suffer from design flaws that were never corrected.

Both the A/C evaporator and the wiring harness issue were addressed in the final revision of the 140.

Neat trivia. The 1999 model 140 S class was only produced for the American market. The 220 started production in Europe earlier than the 2000 release in the American market and the 140 was held over until they could get signifigant numbers of the 220 chassis cars produced.

One potential problem area for 1998 is the 722.6 trans. Read the trans adaptation values before buying, can give some indication of trans health.

I'm not really sure if you can avoid problems with the 722.6 unless you want to do a lot of tire kicking or are just not picky about color and options. There is a lot of misinformation about this transmission and many owners have not had them serviced correctly. If you catch the problems early you can repair them "cheaply" without having to do a complete rebuild. While checking the transmission on the Star diagnostics computer is important more important would be having the transmission serviced the moment you take delivery of the car even if things look good.

Personally if given the choice between having my dashboard ripped out or wiring harness issues that could cause fires and having a transmission rebuilt I would go with the transmission problems. I recently did a repair on my 722.6 transmission at my mechanic for under 1k. Evaporators are at least $2500-$3500 and wiring harness issues are $1000-$1500 for just the engine harness (your interior and the rest of your car is still riddled with biodegradable wiring that will eventually fail).

For years I was spooked by the various forum reports on the W140. I stuck with 124's. Then about 5 months ago I began searching for a '97 - '99 S320.
Luckily, I found one within 20 miles of me. Full dealer service records, 109K miles, Black Opal with Grey Leather, trunk CD Player. Like your prospective vehicle, it some major receipts. Head Gasket at around 70K, Blower motor regulator, new windshield, MAS sensor, and some other things. I think that by '97 wiring harness issues were resolved. Evaporator, could happen but that's not the end of the world.
I paid $11,700. Recommend a Pre-Purchase Inspection at a good MB indy.

I went back through all the 90,000 mile services even though there was a dealer receipt for them. I don't trust that all this was done. I changed a serpentine belt that looked like the original one. I had the lower control arm bushings replaced. I replaced the front shocks, just for the hell of it. Also replaced the front rotors and pads because the PO had them turned at a gas station shop. He knew he was trading the car. I put on new Bridgestone Turanzas and had them Road Force balanced.

I love the car. It put's the 124 to shame luxury wise. Heated seats, super quiet on the highway. The projector headlights aren't the equal of my 124 Euros, but they are pretty good. Check that the mirrors fold back and forth correctly.

This is a complex car, but powertrain wise it should be very reliable. Hard to beat the M104 for reliability and it is a super clean layout in that huge engine bay. In the '97-99 it's 228 HP and has the revised very simple belt-tensioner. Electric airpump. I did my own tranny service pretty much immediately. I really like the adaptive transmission. The seats are the most comfortable I have ever experienced. Love the climate control system. Love the Bose audio system! Paint quality is great, not a trace of the orange-peel that I have observed on some very new MB's. Not a hint of rust anywhere (it lived it's first 3 years in NJ).

So assuming the price isn't in the clouds, I would go for it.

Steve

You know, that is a great point that is continuously over-looked and never brought up.

All 1993-1995 Mercedes cars have this biodegradable wiring all over the entire car, yet the only one that we warn people about is the wiring harness in the engine.

Maybe it is advisable to avoid all cars during this three year period.

Bad wiring is a common issue in many other European cars. The heat in the engine compartment makes the process happen faster for the engine compartment. I have test driven MANY European cars with home brew wiring jobs that were tucked under the carpet and into door sills with make shift fuse boxes so that their tail lights and other accessories work. At least with a Mercedes you can still get parts and the engine compartment is a harness rather than just a whole car loom. The only problem is a lot of the wiring runs through the unit body so the car essentially has to be totally disassembled in order to replace the wiring inside the car. Many other European makers have a certain range of years that are hard to find. This is mostly because electrical issues have caused these cars to be parted out and only the most dedicated and patient owners have invested the time and money to fix them correctly. Some car makers are long gone and many owners have to make their own wiring harness.

Realistically the interior harness probably will last a great deal longer than the one in the engine compartment. Most of these cars are not going to start seeing major issues for many years.

I keep my cars very long term and plan ahead for many years of their service. I love 140's and even if the wiring issues had not been corrected by the 1999 revision I still would have bought one. Although the Wiring issues and A/C Evaporator were motivating factors for me looking at only 1999 model cars.

The wiring harness problem was fixed after 1995 production models.

The A/C evaporator problem was NEVER fixed on W140s !!!

Why? Simple: the problem with the evaporator comes from the mix of copper and alluminun on the unit. Mercedes insisted on using this same combo until the end, even worse, if you buy an evap to replace a failing unit from an authorized M.B. dealer you will get the same DEFECTIVE copper/alluminun evap.

Many people believe the '98 sand '99s W140s are inmune to the evap failure, but they are not. They were simply to new to start showing the problems as older 90's models were doing. Eventually, they will all fail.

The only solution is to switch to an aftermarket FULL copper evap when the original fails.

And the aftermarket company that makes the FULL copper evaporater is made by ACM, I believe.

It's been mentioned here before if you experiment with the search function.

Where are you getting your information from? I find it hard to believe Mercedes would intentionally ignore such a huge problem for over 8 years through the entire production run of their top of the line car.

As a matter of proffesional courtesy I rather not reveal my source, but believe me, IT IS TRUE !

Actually, to get things even worse, evaps that were early changed on early 90's models are already starting to fail for the SECOND time around because of the same design fault.

Ignore the problem??? No, they haven't ignore it, they are fully aware of the whole situation. They just made numbers and found out that it is more exponsive for them to recognize the problem, design a new evap, and give the previous owners legal proof to demand a new evap free of charge. Anyway, they are making more money than they want with the labour costs of replacing the evaps on existing W140s.

That philosophy is becoming less attractive and more expensive in the long run for big companies. It works great until you find that one owner who has the time and motivation to get a class action started. I'm surprised the wiring harness people have not jumped on the bandwagon yet and hauled MB into painful ugly litigation.

THANKS everyone for your input, I passed on the W140 for now - really need to stay with the wagons for the foreseable future -

Brian

Brian,

With as much good information as this board has there is a lot of bad information as well. Don't let the horror stories of the 140 scare you off. Its really a wonderful car. Many of the horror stories are from people who did not understand their cars and took them to mechanics who also did not understand their cars.

Robert Chase