Definitive list of what goes wrong on a '93/'94/'95 E-class M104
 

Hi guys. First post. I'm looking at '94/'95 E320 wagons with about 100K miles. I'm trying to figure out what it is I should be prepared to fix in case it has not been done. I hope this thread will help others trying to buy used W124 E320's in a "one stop" kind of way.

From the research I've done in the last few days, it seems this is what commonly goes wrong with these cars (I'll edit it as replies and contributions come in):

-Head gasket (might as well do a complete head job while at it) (1)
-Engine wiring harness (1)
-OVP relay
-Evaporator
-Water pump
-Radiator/hoses
-Carbon deposits in manifolds
-Throttle actuator

I'd appreciate if you guys could help by adding items and ranking them in terms of frequency from 1 to 3. For example the head gasket seems to be an issue in ALL cars, so it gets a (1). If only very few people have trouble with the tranny then it gets a (3), etc. A price estimate would be nice too.

Thanks!

Add:

-EGR tube gets blocked at roughly 50K
-Flex disc replacement

You should edit your first post to include 1993 models, which have the same M104 engine, but didn't get the badge change.

1993 300E's have the same 3.2 liter M104 engine. In the rest of the world, they were badged as 320E's, which takes away from the confusion.

1993 W124's with the 2.8 liter M104 engine were badged as 300E 2.8. This engine and chassis shares the same problems as the 300E (3.2) and E320 models.

serpentine belt tensioner, a/c drier, power window regulators are all pretty common I think. they all happened to me.

After giving it some more thought, I would only list items that are systemic problems with the chassis. Not items that are mileage dependent, like the water pump, which go out on all cars.

I would only put on my list the following:

head gasket, wiring harness, throttle actuator, and radiator (the originals had plastic knecks, which break).

For the wagon specifically, the way back side windows tend to leak around the edges. Our heater/ac blower fan started to squeak at about 80,000. Great vehicle. Enjoy.

After looking at many nice lower mileage Benz's (and from getting burned a couple of times) I think an average mileage car WITH service history so you can determine if some or all of those problems have been dealt with is the way to go. If dealing with an MB dealer - only that dealer will have repair records of what has been done at that specific dealer. Their system does not contain repair work performed at other dealers.
The dealer can print you a copy of those records and explain them to you (sometimes they use codes). Any dealer that is worth anything will contact any previous owners and ask them if it is o.k. for them to give you info. about the car - they will also mark out any information about the previous owner and costs that are on the repair printout.
I just did this at the local dealer two days ago. If the salesman does not want to help with this either ask to see the service representative or walk away but not before telling him why you are NOT going to consider purchasing that vehicle from him.

94/95 E 320 Problems
 

I bought my E320 Cabriolet used, at 35,000 miles, from a MB dealer in Bethesda, Maryland. 2,000 miles later, the top pump failed; thank God the dealer replaced it free under warranty, it woulda cost about $4,000. Since then I've put 65,000 miles on the card and have had three problems I'd consider non-rountine:
1. Water Pump failed twice. Dealer replaced it at 50,000 then it failed again at 60,000. My local Cape Cod mechanic, who fixed it the second time, said the dealer had installed it improperly. I couldn't get the dealer to agree, even when I showed how them the parts had been screwed in wrong. Spent nearly $3000 altogether.

2. Electrical gremlins. Passenger-side seatbelt system has a mind of its own; I have to drive with the belt locked to keep it from operating. Combo-switch failed at 75K, no brights and erratic wipers. Warning light for burned-out bulb remains on despite replacement of all bulbs. When I step on the brake (without headlights on) the light inside the ashtray lights, go figure. Antenna mast system grounded out, and burned out alternator (in a snowstorm of course). Ignition fuse has popped 3 or 4 times, rain or shine. Became quite adept at hopping out and replacing the fuse while smiling at stalled traffic behind me.

4. Transmission. Originally, just annoying -- when cold, car didn't want to shift from first gear until revved high. Now, reverse is failing and there's leakage at the front pump seal; I've learned this is a common problem with the 722.369 tranny. I only wish the $3500 needed to overhaul it was equally so common.

Ah well, it's still a snappy car and a babe magnet.

I should qualify to answer this >
 

My 94 E320 wagon just turned 100,000 miles. Items that wore out and needed replacement included exhaust system, rubber components in front and rear suspension, steering shock, serpentine belt tensioner, flex disc, engine mounts, fuel pump and water pump. Add the head gasket and wiring harness which are just bad designs, and the timing cover gasket which is probably a bad design. Got a head job when the head gasket went. The car runs great now, but has cost a lot of repair dollars even considering it is 10 years old.

As Paul (suginami) suggests, some of these "faults" are fair "wear & tear" that could reasonably be expected on any vehicle of this age with high mileage whereas others are problems they could be prematurely encountered on the W124. I believe your searches have revealed the common ones but also be aware that not all cars suffer from all these problems. Some W124 owners (even '80s models) have not suffered a head gasket or water pump failure and many owners of '93-'95 models have yet to suffer as a result of a faulty engine wiring harness (although it appears this one will be inevitable).

Since you mention a wagon version I will add a couple unique to the 124 wagon variant. The tailgate gas pressure springs will eventually weaken and be unable to support the tailgate. This is typical at the age of the 124 now if they have not already been replaced. The wiring harness into the tailgate can also eventually fatigue and develop open circuits due to flexing with the opening and closing of the tailgate. I have had to attend to both of these faults in recent years on our '90 300TE which is now showing about 185,000km (about 115,000 miles). During the six years we have owned it I have also replaced a head gasket (affects M103 as well as M104 engines) and valve stem seals, a belt tensioner, rear suspension air cells, a tailshaft flex coupling, front brake hoses and mufflers (plus normal maintenance items such as brake pads and filters etc.).

Over the past few years that my father has owned his '93 E320 124 coupe now showing about 135,000km, I have replaced its engine wiring harness, water pump, belt tensioner and coolant reservoir. It is now also showing signs of a pending head gasket failure.

So in conclusion, most of the items that everyone above has been pointing are regular wear and tear items that occur on every used car, and are both mileage and age dependent. Belts, hoses, water pumps, flex discs, yada yada yada are all regular items that wear out on all cars.

The original poster is trying to identify systemic failures that are unique to 1993 300E (3.2's), 1993 300E 2.8's / 1994-1995 E320's. In other words, 124.032 chassis cars.

He is looking at wagons, and the only item pointed out that is unique to this car is the water leaks at the back side windows. I don't think anyone looking at a used Mercedes wagon would ever think to look for leaking rear windows.

The systemic failure items on 124.032's, that are unique to this chassis, due to poor original designs and have been fixed with updated parts are:

1. oil leaks at head gasket
2. crumbling engine wiring harness insulation
3. OVP
4. radiator (originals have plastic necks which break

The above have failed on most cars, and if original, will certainly need updating.

Thanks guys. This is great info. :)

One more...
 

Don't forget the leak at the front timing cover. Very common.

Not mentioned above and did happen on my E 320 T:

1/ Water leak through the power anntena base.

2/ Automatic seat lock release for rear seat backrests (did not work and seats could not be lowered). I hear from the dealer this is a common fault.

3/ The security pin that hols the bulbs for the rear lamps brakes easily, especially if by chance the spare wheel touches it.

4/ Admitted by the dealer: as a design fault, the rear speaker wiring (the ones located on the rear door armrests brakes easily, creating a ground and blowing the speaker(s).

5/ Sunroof operation is a nightmare (common in all W124s), especially if you use it often.

I'll second (or third) the leaky rear windows and the sticking rear seat folddown mechanism, as well as all of the other more common stuff (head gasket, etc)
Brian