Hi everyone,

I am new here and, even though I've loved MB for years and I know everything about all post 1999 MBs, I am relatively ignorant when it comes to the classic Benzes. I have recently fallen in love with the W126 chassis after reading on several forums (including this one) that many MB enthusiasts consider it to be the best Benz chassis ever produced and that the diesel engines (the I-5 in particular) never seem to die.

So, I just came across a 1984 300SD for sale. It is in excellent shape, with just 145,xxx miles and runs very well. I was just wondering, what should I be aware of when purchasing this vehicle? Will it cost me lots of money to keep up? I intend to use it as my daily driver and put about 14,000 miles on it per year.

After reading the posts here, I've already learned that the vacuum system seems to give issues resulting in problems with the power locks, the central locking system and the engine shut off. I've also read about A/C nighmares. Are these all expensive repairs? What else should I be expecting? I really don't want to get myself into something that will just use up all my money.

Please advise.

Thanks,
Richard

The 126 chassis is indeed IMHO among the most beautiful and durable MB made, and as you pointed out, when coupled w/ the OM617 it becomes a rock solid performer that should thrive on the type of mileage you plan to rack up.

Issues - Front end. Nothing wrong with them as designed, but most of the cars out there will need replacement of the front end suspension components soon. Since you're planning on racking up a lot of miles, you'll probably want a car in which this work has been done all ready. As a DIY job it's doable, but time consuming. Parts are $400-500, but if the whole front end labor is around 13 hours I think.

Window seal - Many of these cars have a problem with the back window leaking some amount - check the trunk after it rains, or actually look lie face up in the trunk and check for tell-tale signs of rust around the package tray.

ACC - the monovalve goes out leading to wierd heating problems, but is a 10 minute/$20 repair with a screwdriver and new insert. This is not the ACC with the nightmare servo that was lifted from Chrysler. The most frequent problems with this system is that the vacuum pods that control the air flaps go out, leading to air coming out of the wrong vents - (can sometimes require the whole dash to be removed to replace all of them, although I believe several can be reached without such extreme effort) or that the push button controler goes out (replace at $$$, but sometimes resoldering it will bring it back to life).

Vacuum - These cars have a separate electric pump for the locks, and I don't think you see as many issues with those as with older models.

Sunroof - I think the 84 may have the tilt/slide type of roof. If so, and it breaks, plan on $2000 for repairs - not readily DIY. The slide only type of roof is DIY.

There are really no issues with the OM617. It is what it is, loud and unrefined by today's standards, but tough, durable and easy to work on. Make sure the valves are adjusted before you even think about coming here with any performance complaints. You can expect your 0-60 time to be around 15 sec, and to get somewhere around 22-28 mpg.

Great great cars. Good luck.

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Tjohn

82 300 SD
77 450 SL (gone)

I too own an 84 300 SD and it was the best purchase of my life! I have had no major issues (including the one's listed above) with my car and she just rolled 225,000 this morning. The 84 doesn't have the multi-adjustable roof...it only slides back and forth. My car came from the original owner with everything in tact and in tip top shape. The pre-purchase review left my mechanic stating "either you get it or I'll buy it". Make sure you have the mechanic look it over and then go for it.

Since you mentioned money twice, I will say that as a general rule,

IF YOU ENJOY DOING REPAIR WORK YOURSELF, BUY IT.

IF YOU DON'T, DON'T....

These things are cheap to work on when you have time and enjoy them. But things can go in cycles and if you farm out all your repairs, you could spend some money in a hurry.

Don

__________________
DAILY DRIVERS:
'84 300DT 298k (Aubrey's)
'99.5 Jetta TDI IV 251k (Julie's)
'97 Jetta TDI 127k (Amber's)
'97 Jetta TDI 186k (Matt's)
'96 Passat TDI 237k (Don's
'84 300D 211k Mint (Arne- Undergoing Greasecar Conversion)

SOLD:
'82 240D 229k (Matt's - Converted-300DT w/ 4 speed

Thank you all for your replies. I truly appreciate them.

I talked to my friend who is a mechanic (not on MBs though, but a car is still a car) and he was wondering why it would need a valve adjustment every 15,000 miles. He said valve adjustments are only necessary for much older cars. So at this point, I too am wondering why you all keep mentioning the valve adjustments.

I have decided to purchase the car anyway. It feels like a big cadillac when you're driving it LOL

These are older cars, that is why they need valve adjustments. IF you tell your mechanic friend that they do not have hydraulic lifters then he should get it.

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andy t
'78 300d
'95 volvo 850, wagon
'86 300sdl - engine out, maybe I'll have it rolling by June

whole bunch o' bicycles

I may well be prejudice but to me the 126 is one of the best Mercedes . My experence with my two 81 SD (I'm only driving the most recent one as for now) is that these are simply among the finest cars ever built.Once you have done the normal getting it up to snuff repairs that most twenty year old cars need I belive you will find that you have much less upkeep cost than on many new cars.

All that and when shined up they still turn heads ,ride in comfort, very safe,handle well, geat good milage for a big car(24 to 28) have big back seat, big trunk. will cruise at speed, great brakes. my finger is getting tired.......

William Rogers.........

74 240 D
81 SD
81SD
86 Euro 500 SE

Richard,
You didn't indicate on your profile or in the original message where you live. Check for rust, including getting under the vehicle. Expect A/C system leaks with a 20 year old car.

Like diesel don said, if you are going to do the work yourself great. If you are going to send the repairs out to someone, the car can run into a pile of money. If you are willing to do 50% of the work yourself, that might be OK is the car is in good shape AND you have a second car for back up.

ee

__________________
84 300DT Puke Yellow. Totalled after 438,000
84 300DT Orient Red. 169,000 (actual mileage may vary)
2002 Explorer EB (wife's)

Well I'll talk to him about it today. We will run through the car and see what needs to be done and get started.

I purchased it yesterday. The dealer said he had done some work on the front end suspension, put in a brand new battery with lots of power, new air filter, detailed the car inside out, brand new tires, new wiper blades, reconditioned the leather seats, and delivered it with a full tank of diesel. All in all he was asking for $5900. I smashed it down to $4700 (it wasn't that hard to do since I was paying cash). Drove the car home last night. Engine sounds "like a diesel" when you're outside (klah klah klah) but once you get inside the noise is reduced enormously. The dealer even told me that I could replace the sound proofing material in the hood and trunk with new ones and get an even more isolated interior.

And as for acceleration... I think you people all got me to expect diesels to be FREAKING SLOW. This car moves! I was passing cars on the highway at 3000 revs. Not bad at all for a 3740 lb 20 year old car (make that 3950lb with me driving). It takes off really slowly indeed (before 2100rpm when the turbo kicks in), but highway merging and passing is good enough -- and that's something coming from someone who currently owns gasoline cars and has owned really fast cars before (1996 Mazda RX-7, 1998 Covette). Speaking of the 'Vette, I hit 85mph last night on the highway and this beast felt more stable than anything I've driven before, including other heavier, newer cars. These Germans must know some witchcraft!

My mom just came over to my house this morning and right now I'm fighting over the Benz with her...!

I live in Kansas City, MO. Sorry... I've just added that to my profile now. Yes, almost all 12+ year old cars are rusting here thanks to the salt that we use in winter. But this car has none whatsoever! It is a one owner car (the original owner is a German medical doctor) and he never drove it in winter. That also explains why it has such low miles (144,xxx).

I have no experience with working on cars. I didn't even know how to do an oil change until last week. I've always had new cars. However I have a close friend that I do big favors for and he is a mechanic. He encouraged me to buy the car because he said he can work on it (he particularly liked the lots of space under the hood which makes it easier to work on). He just bought a 1981 Toyota Diesel truck for himself, so he is excited to learn more about diesels by working on them. Also, I'm in the process of downsizing which means selling all my other cars (one sold, one to go) to get money to invest in my new business. That way I won't take a business loan, and I don't yet have enough equity in my home to take a home equity loan, but I have more than enough money in my cars. This will be my only car. But my girlfriend lives with me and she has a brand new car so I kind of have some backup.

The dealer told me that he gets MB parts very cheaply since he orders about $9,000 worth of parts per month. So he said that if I need anything he can get it for me. Also, I intend to start learning how to work on cars. I love to learn new things, and this sounds exciting!

Click on FastLane online catalog at the top of the page this site offers parts at considerable! saving over dealer cost.Plus Phil that runs Parts Shop and FastLane get the parts out fast and bend over backwards to help............

William Rogers.........


"Bet Low Think Big"