95 S 500 Problems that stand out ?

There were complaints about steering vibrations - the tire guys blamed M-B and M-B blamed the tires. And the owners complained.

Investigate the a/c evaporator - apparently when it fails the entire dash assembly needs to be removed to get to the evaporator - heavy labor cost.

Otherwise, the owners of these big old tanks seem to love 'em.

"Take A Guess" wrote in message news:4JKdnVlLf---fDzYnZ2dnUVZ snipped-for-privacy@comcast.com...

I've had a '95 S420 for about 5 years, from 90K miles to 193K now.

They will last forever, but it takes effort to support them. That effort can either be handing over a credit card, or turning a wrench, or a combination of both. They are not cheap cars to own. In those five years, here's what I've learned...

W140 Laws of the universe:

1) Keep on top of things. These various systems on these cars are interrelated in unexpected ways. A small failure in one that you might tolerate for a while may cause unexpected expensive problems. If something quits working, fix it right away. See Ugly Story below. 2) Be patient when working on it. The engine compartment connectors on mine are brittle across the board. If you break one, it's a pain trying to buy just a connector without buying the whole harness/component it's attached to. The interior trim is also delicate and expensive. The small hand size wood inserts on the rear doors are 120 USD each, and easy to crack when changing window regulators. The lower console trim piece is 650 USD and easy to damage when working in dash area. 3) Scour the internet for info. There are some outstanding sites with great info. Search for W140 (that's the chassis number for the car). 4) Unless you've got money, do as much of the work yourself as possible. You'll save big bucks, learn your car, and spend less time in loaners. 5) Find a reliable, competent, and honest shop to do work for you. Do this BEFORE you buy it. Have them inspect the car first as well. Get to know your mechanic. Don't buy the car, and then find out that there's no good local place to rely on. IMHO, never go to dealership for service. There are exceptions to that, but I've found none in SE Michigan. See Ugly Story below. 6) Be realistic. Financially, this car is more like owning a boat that a normal car. It will take a lot of maintenance and money, regardless of who does the work. If you are looking for a low hassle vehicle, this ain't it. See Ugly Story below.

Generalities: Issues common to all W140s

1) A/C Evaporator...Eventually WILL fail. Requires entire dash removal for replacement...3/4,000 USD 2) Change timing chain every 100K miles, don't wait for it to fail! 3) Heating system duovalve...lasts about 125K miles...coil failure. 3/400 USD for part and an afternoon replacing. Can be rewound...instructions on web. 4) Rear window regulators...WILL fail. The replacement 200 USD+/- uses a metallic piece in place of the original plastic. Solid afternoon to get into the door and replace. 5) Front wheel vibration...VERY sensitive to misalignment and requires non standard alignment procedure. I real align about every 6 months, and always after a tire change or any suspension work. If you don't, you will wear tires and front suspension parts and it will cost you more in the long run. 6) Engine harness...WILL fail (and probably has already to one degree or another)...biodegradable insulation degrades in place prematurely. Will eventually cause loss of performance, odd system failure codes, and possibly engine damage in extreme cases. Replacement part about 500 USD and a day to replace. 7) Right side headlight wiper arm. Just plain won't work. Something to do with a bad current limiter design I think. Haven't bothered enough yet to look into it seriously. 8) HVAC Blower motor regulator. Prone to failure due to overheating. Must change HVAC air filter annually or the filter plugs up, reduces airflow past the regulator, and it overheats.

Specifics: What I've had to do...

1) Duovalve...repaired myself by rewinding coils...real pain, but cost only 50 USD opposed to just 350 USD for part. 2) A/C control module...replaced part. 500 USD for part, and afternoon to replace. Getting to it is fun. 3) Driver's door check strap. Was lazy and paid dealer to do it. 150 USD 4) Both rear window regulators. Make sure you get the stainless OEM rivets (3 a side). 5) PSE vacuum pump...powers door locks, trunk release, gas cap release, etc. 500 USD and 1/2 hour to replace. See Ugly Story below. 6) New rear shocks and bushings...1000 USD at shop 7) Overhauled front suspension...2000 USD 8) New tires (first set went fast before I learned of front end shake, hence front susp ohaul)...900 USD a round 9) Timing chain. 10) Engine harness...be careful when handling connectors. Some are not obvious as to how they work, and all are brittle. 11) Aux vacuum accumulator hose. See Ugly Story below. 12) Transmission rebuild...2600 USD and week in shop. See Ugly Story below. 13) HVAC blower motor regulator. 350 USD and 1 hour to replace.

Ugly Story: Started experiencing hard shift on transmission. Nothing ridiculous, but different than it's normal silkiness. Figured it was big bucks rebuild time (160K miles), and decided to keep an eye on it while saving money for rebuild. Over a month, shifting got worse, and I had some unexpected expenditures, so had to wait another month before addressing. I also notice that when accelerating, the HVAC unit seems to act funny. Then the door locks quit working. Tracked problem down to PSE pump under back seat. Ordered new one and replaced. I also happened to notice that the transmission seamed to work better now, although I didn't put the two together. Two weeks later, new PSE pump fails, and trans starts to shift like a road grader. Also, when accelerating, the HVAC unit now goes into full failsafe mode and routes everything through the defroster vents. Finally take it in. Final cost...1500 USD for 3 PSE pumps, 2600 USD for trans rebuild, and a week in the shop. Root cause...There is a vacuum accumulator under the right front fender. It supplies extra vacuum when the engine does not create enough. This accumulator serves the door/trunk lock system, the HVAC system, and the transmission. The hose to the tank had gone bad. The PSE pump started to work overtime to supply vacuum to the tank and eventually failed. This caused the transmission to shift hard, wear parts quickly and forced the rebuild. Bottom line...If I not decided to put it off, had paid attention to the full range of symptoms (locks dead, HVAC behavior, and trans shifting), NOT made the assumption that they couldn't possibly be related, done some research, and used my vacuum gage to do some actual debugging in stead of just replacing the pump, I would have spent 30 USD and an afternoon replacing the hose. As it was, I spent over

4000 USD and drove my son's car for the week.

On the Other Hand: IMHO, there's nothing quite like a W140. I think they are the finest looking 4 door sedan of modern times. The ride is outrageous for a +5000 pound car. It is as silent and solid as bank vault. The interior is huge, classy and comfortable. It's got lots of punch (and I've only got the 420, you're talking about a 500), and cruises like a dream on the highway getting darn near 30 mpg at speed. My only problem is that I've been ruined when it come to buying another car. Every other car I get into now seems loud, cheap, and flimsy.

Bottom Line: I love the car. It's not something that will stand the scrutiny of an objective evaluation, but I bought it for subjective reasons. They are expensive to own, but from an emotional standpoint, well worth the cost. The maintenance hassles all pale when doing 80mph up I-75 on Friday afternoon, while listening to the fine details of string music that are inaudible in most cars. Give it a good wash and wax, then sit in a lawn chair about 10 feet away off a front corner and look at it. That's why it's worth it.

I should have added: These are the last of heavy, old fashioned, damn the cost (or weight (or expense)) cars.

These are antithetical to everything that modern cars are trying to be - lighter, more easily maintained, more agile and fuel efficient.

An S320 is a relative bargain - who wants it?

I have owned a 97 S500 for about four years. Watch out for shock issues like oil leakage on the shock or the control arm that holds the shock in place. If there is a problem it is about an $800 per shock issue. I am currently having problems with speed sensors on my car (see my posting of today). I put a transmission in my car in July. It had 150,000 miles so I wasn?t too surprised that it needed a tranny but I was surprised that the problem was not mechanical but sensor related. The sensor being an integrals component of the transmission located inside the transmission casing. Also check the blower motor strength in the air/heating system, another $1,000 issue. Good luck on the S500 but be aware that any problem is going to be expensive and adjust your purchase price accordingly

"JMSO" wrote