W124 Buyers Guide
There are quite a few great buyers guides across the internet...Here are some I have found over the years:
Very thorough so I recommend reading it.
Here are my personal thoughts. I shall give a section to each off independently. Categories are 1) Value 2) Comfort/Interior 3) Longevity 4) Maintenance 5) Style/Exterior.
this article excludes the 500E due to its rarity.
I will include negatives in each section to maintain a balanced guide. This would not be a true buyers guide without the negatives.
Here are my personal thoughts. I shall give a section to each off independently. Categories are 1) Value 2) Comfort/Interior 3) Longevity 4) Maintenance 5) Style/Exterior. this article excludes the 500E due to its rarity.
I will include negatives in each section to maintain a balanced guide. This would not be a true buyers guide without the negatives.
--In the current market (2010), you can find a nice example of a w124 anywhere from $1500-$5000 spanning from model years 1986-1995. The purchase price is only in relation to the maintenance history, or lack-thereof. Since they are between 15 and 23 years old, you will find a wide range of history on each car. Some will have perfect, dealer-maintained history, others will have sporadic 'european' shop maintenance records and others will have nothing at all. The main point that you need to establish is what maintenance has been done. A complete lack of maintenance, even on a low mileage car, could very quickly and easily add up to $5000 in the course of 6 months at a local mechanic. Even yourself, parts alone would be $15000 plus a bunch of your time. For example, my lack-of-maintenance 260E has added up to about $3k in parts in the last year. At this point I think I am pretty close to catch up, but this is no labor since I did it all myself. I would estimate this with labor would be well over $7-8k. Unless you are a DIY type of guy, don't take this path! Buy a model that is more expensive, but comes with great solid history.
The point that you must understand here is that you REALLY are taking a risk in purchasing a car without any history. If the price is really right, I would still get at a minimum a full compression and leakdown test performed. This will tell you the condition of the internals of the engine. Ideally, you want ~180PSI on each cylinder with no more than a 10% difference between each cylinders. Leakdown ideally should be less than 20% on all cylinders. If one cylinder is not getting compression, you could end up chasing ghosts in the ignition and fuel system spending tons of money when the true culprit is the most expensive, and difficult one.
A purchase of a car that has history and is in great shape can become an incredible purchase. Seeing as these cars no longer have any depreciation, you have nothing to worry about in that department. All your costs will be maintenance, gas, insurance and emissions if need be!
Average City/Highway Fuel Economy on these cars are around the low 20's for the inline 6 M103 models, low to mid 20's on the inline 6 M104 model and low 20's with the V8 models. Everybody drives differently so take 'posted' numbers with a grain of salt.
Insurance costs on these cars varies with age, but it is pretty cheap. You must remember this $2-3k car cost well over $50k brand new a long time ago!
2) Comfort / Interior
--Most MB's came with Vinyl aka MBTex which I personally believe is pretty comfortable. It maintains its shape amazingly with age. Most models came with electronic seats which is a nice addition which allows a multitude of differing positions. If you are short, you may feel more like a giant sitting on his throne now. Other models, and later came with Leather which is just as comfortable. One of the best things I enjoy about the the W124 is the viewing angles. There are very few blind spots and you have an amazing field of view all around the car. This also falls under the safety section too!
Rear seating is relatively spacious. There is a fold down arm rest that can be put down in place of the middle seat. Unfortunately there is no fold'able rear seats on the sedans since the gas tank sits behind there. A little bit of a shame since carrying large items is not as useful. The wagons have complete fold'able down rear seats. They go into the floor and the bottom seat can be either removed entirely or pushed up against the back of the front seats. This gives a TON of space. Not quite 'tall' enough for a sofa unfortunately, but it is close!
Rear parcel shelf has a middle fold up emergency medical kit installed. This place also gives great opportunities for audio installs for those inclined (no, this does not mean throw away the medical kit, just put it somewhere else INSIDE the car)
Later models with dual airbags have the glovebox moved into the center console between the front seats. Unfortunately this does not leave much space for your random junk you would otherwise throw in the glovebox for years on end (Wow this is from High School!). Yes, you people know who you are! The early models with the single driver airbag includes a glovebox gives a lot of space though. Unfortunately no cup holders. What???? Sorry. None at all. Some people install them into the doors, but I recommend buying (for single airbag models) a center holder unit that you can buy at a local walmart/target. There's your cup holder.
In hot climates, your cooling capacity for the engine and Air Conditioning will be pushed. In Arizona @ 115F with a brand new A/C system for the most part, the vent temperatures are COLD, but the car's internal ambient struggles. I would say it is slightly less than 'comfortable', but it is 115F+ so this may not affect everybody.
Full size spare! This is just an awesome item to add on. The wagon models keep it tucked away to the left side of the hatch, the sedans have it under the carpet in the trunk.
Ride quality is quite remarkable. The car should be very quiet on the freeway and a real joy to drive. It should feel very firm and in control. It should not wonder.
--I shall cover everything except anything engine-wise. Simply interior, exterior and accessories.
First things first -- I highly recommend getting a tint, even if it is a small one ie 50 or 70% due to state regulations. This will dramatically reduce the sun wear on the interior. Interior-wise, most items should still be in good shape if the car had even been half cared for. The dash panel can develop cracks with use of 'Armorall' products (unconfirmed, but I used to use it and I now have cracks a year later. Go figure) but they rarely become shriveled and wrecked. Even after 23 years, my 260E's is crack-free and my 300TE has just a few hairline cracks. Not too bad. MBTex lasts forever, literally. The sun can dry the seats out with time so this is why I recommend a tint all around with UV protection. The MBTex should be supple, not hard. Leather is leather although I understand it lasts longer and is of much better quality when compared with similar cars. It entirely depends on usage. Just don't expect it to hold up to the same standard as MBTex will. The rear seats for the most part should be in really nice condition seeing as most people do not use them often.
Audio speakers will be outdated and falling apart if they have not been changed. The paper cones will need to be replaced if you plan to do any audio upgrades. Any modern day speaker will sound much better with the integrated tweeter.
Sunroof's can have possible issues with the plastic rails which can break. If taken to a shop it can be relatively expensive.
The famous evaporator leaks. This is caused by the different materials (copper and Aluminum) since it expands and contracts causing leaks. This requires complete removal of the interior to reach the heater box, and evacuation of the A/C system. Vacuum pods which control the air flaps will lose their vacuum over time. Total PARTS cost for evap and pod replacement is around $600. It is considered a 12 hour job. So do the math if you plan to take it to a shop. BIG thing to check when purchasing the car. Once replaced with an all-Al one, it should last indefinitely.
Odometers will fail at some point. A shop should charge about $120-$200 to fix it. The cogs will wear. It can happen at any point. I have 'heard' this occurs due to resetting the trip meter while moving which causes premature wear on the gears. Makes sense at the least...
Cruise Control can be erratic -- If it keeps blipping the throttle to maintain speed this is the cruise control amplifier. It can be either resoldered or replaced.
Most electronic relays, along with the cruise control amplifier can crack with age (microfractures in the solder joints). Another example is erratic wiper movements and the light bulb warning light that stays on even though all bulbs are functional. Most of the time everything will function, but every now and again you may find 'some' odd behavior going on. More than likely it the relay.
Window motors can die, or the wiring can crack and sever via the door grommet. This is very common along with the window switches.
This may seem like a long expensive list, but you will probably find if the car has been maintenance little if any will be apparent. What you should do is go in there with a 'list' of the above that you can check, or at least some of them knowing these are the most 'common' problems.
OE U.S. Headlights suck. Period. The plastic will turn a yellowish color and the light output sucks. Early models should purchase some OE Bosch Euro lights, or I recommend some aftermarket TYC or Depo headlights to keep the OE look. Both are great quality and can be had for under $200.
--I shall try to group everything into sections so as an almost 'buying checklist' if you are mechanically-inclined. I personally only have experience with the M103, so this will exclude the M104 and M117 although many elements carry over.
a) Engine M103 ...The W124 in the US comes in a 2.6L and 3.0L M103 engine. This inline 6 sports 160HP and 177HP respectively. Both get similar fuel economy due to different rear differential. The differences between the 2.6 and 3.0 are a larger bore and valves, otherwise everything is identical including all ignition and fuel systems.
The M103 tends to have a number of idling issues which can become quite fun to resolve after all basic tune up elements have been done. Pre 89 models have an updated camshaft and rocker design that wears less so keep this in mind as you may find scored lifters and camshafts, especially if the oil has not been religiously changed.
Most common issue is burning oil. The valve stem seals will harden allowing oil to seep down. You will find it by simply looking at the spark plugs. If an oily black/grey residue has built up, more than likely the stem seals are leaking. This can be done without removing the head with a valve spring compressor. Most of the time though at anywhere over 80k, the original guides with age will have developed some play, so the valve stem seal replacement is a band-aid fix for another issue. Don't worry about it though until the head is removed for a gasket or other changes.
The original gasket can leak anywhere over 100k. Most common place is the far back left corner at which it will leak oil. Alternatively, oil will leak into the coolant passages and will contaminate the cooling system. This is an easy check by simply popping the reservoir cap and looking since oil will rise to the surface. Most of the time you will not lose compression so the car will drive fine, but prolonged driving with oil in the cooling system will cause more issues and require replacement of a number of cooling items. When doing a head gasket, be proactive and have the head cleaned, skimmed, pressure tested, and the valve guides + seals replaced. It will be a wise investment that should last well over 100-150k, possibly longer since the gaskets are updated and reinforced at the corner where leaks were common.
OE water pumps can last a long time, or suddenly start dripping/gushing out of the weep hole on the bottom of the pump. Check for leaks, otherwise don't worry about it until it fails or you have overheating issues.
Fan clutches are common failure item as with any car...Simply start the car up and it should roar due to it being locked for about 15 seconds.
Engine mounts are hydraulic and will leak out or completely collapse. Vibrations at idle or on the freeway are common. Mounts usually last anywhere from 60-100k. Passenger side is easy, driver side is a little more tricky. OE mounts are recommended over aftermarket.
Leaks at the front cam cover are common. Check under the distributor cap for fresh oil. It will drip down the passenger side of the block at the very front. Not expensive to fix, just common.
The suspension in the rear should be checked for play. Control arm bushings will harden and crack over time allowing for slack causing tire wear. Have someone accelerate while the brake is on. Do the wheels move in the arch? Another way is by accelerating on the freeway...does the car wonder while accelerating then return when you let go?
Subframe mounts with age will begin to crack.
At the front, ball joints, idler arm, tie rod/drag link bushings can tear, steering damper can leak...Most need replacing every 80-100k.
Shocks last about 70-100k. Not much longer than that. You will find the car will bottom out with the tires touching the fender. Replace these with Bilstein HD's or Sports if you plan to lower the car. Cheap alternative to OE that are just as good.
c) Transmission + Driveshaft
Transmissions come in the 722.3 and 722.4 flavor. Both are basically identical other than size. The 722.3 is usually in the 300E and 300TE while the 722.4 is in the 260E. Both can leak from the front pump which requires complete removal. Reverse B3 bands at SOME POINT will fail causing, well, no reverse operation. This requires a rebuild and will cost around $2000. Most failures will occur between 160-240k.
The Front Flex Disk will wear at the bolts allowing play. You can have vibrations or 'clunking' noises when you blip the throttle. They usually last anywhere from 50-100k. You don't want to drive with it. Rear flex disks usually last twice as long as the front.
Occasional flaring between 2-3 can occur. This usually can be resolved by putting in a K1 shift kit for $10. It can be done by simply removing the pan.
Not much else for the transmission. If maintained excluding the B3 reverse bands and leaks, it can last well over 300k. Keep fluid change intervals at every 30k miles.
Again, this may seem like a ton of stuff. And it will be if you purchase a car without history. This is both a list and a warning to those who want to gamble with a car without history. You should by now realize how important history is. There is nothing more expensive than a cheap Mercedes.
--I believe that Mercedes has styled this car far ahead of its time. It is not curvy, yet not too 'cut up' so it seems to blend in with all generation of cars and still maintaining its style. The later style lower cladding was added along with a hood that integrated the grill over the large chrome one. I believe both of these greatly increase the eye-value of the car. Early models can be 'upgraded' to include these items. You just need the cladding and the clips and it bolts right on. The hood will require different headlights, but otherwise bolt on. Other options include AMG or other aftermarket body kits. Most of them look very period and look really great.
-- This is not a performance friendly car. Don't expect to buy a supercharger or turbo kit on the cheap. Twin Turbo kits will cost in excess of $10,000. No I am not kidding. There are no real other mods to increase HP. It already has a cold air intake at stock for those who want to do this -- don't waste your money. Filter 'upgrades' have been proven negligible on dyno's. This car can turn into a very nice handling car with great brakes the right springs, shocks, spring pads/shims and caliper upgrades. Wheels and suspension upgrades are your only real option other than spending huge amounts of money on it. Engine swaps are possible. The best option is a C36 swap.
Wrapping it up
-- So what, in short should I check when viewing a car? What's the most important items to check?
The most important to check are the most difficult aka the most expensive.. 1) Test drive it! How does it drive? CARFAX CARFAX CARFAX!!!!! History?
2) Leak check. Any leaks anywhere? Engine? Transmission?
3) Check coolant reservoir for oil
4) Check oil and transmission fluid. Is it low? Might be a bad sign of neglect
5) Does A/C work? Remember the evaporator leak WILL happen, it is inevitable...it is just when it does.
6) Odometer work? Check against Carfax report
7) Burning oil? Check spark plugs for deposits
8.) Is it on original head gasket?
9) Does reverse engage quickly? Slowly? Have the B3 bands been replaced?
If anybody has anything else they think should be added please post in the comments section and I will add it in! Especially related to the M104 of M117.