28th May 2009, 15:50

I have owned a 300SDL for one year now and the car is fine. Very economical I get 100km on 7liters of diesel. Does anybody know about repairing torn leather seats; IE can I sew them or do they need replacement leather? My main problem is the air-con unit. It works fine and blows cold air but when the weather outside the car is above 83 f then it just blows normal air. The compressor does not come on?! Any suggestions on this would be gratefully received! I even though of putting on an override switch that would force the A/C compressor to engage but I do not know if this is possible or advisable?

Thanks in advance.

29th May 2009, 19:23

Looking down and to the right facing the engine you will see the filter/dryer. On the left side of the dryer you will see a switch that screws into the dryer. Unplug the 2 connectors, make a jumper wire to bypass the A/C cutout switch.

I did this to my 85 300DT and now plan to convert my 1987 300SDL.

Hope this helps.

22nd Jul 2009, 00:06

I have a 300SDL diesel turbo. Runs great, still has little over 300k, and still runs like a beast, but I still can't tell if the shocks are shot though LOL, but man right now everything is OEM; same paint and everything...

I was wondering anyone has the same problem when you press the adj. button on the rear seats and it meshes up the whole front end of the electronics? Like the seats won't adjust the steering wheel etc... if do please contact me on dsengkeo@yahoo.com

Thx for reading.

2nd Oct 2009, 06:39

1987 300sdl is best year for the best SDL Mercedes ever produced. The SDL (350SD/SDL) of the 90's are shameful.

The good = everything sans the bad and the ugly.

The bad = takes long to warm up; seats on spring, no sturdy frame, easily torn and rip, not suitable (recommended) for heavy passengers; power from 0 to 30mph is sinfully slow, but the car takes off on the open road from 0 to 100mph like an airplane. Not recommended for short trips and daily driving less than 10 miles: harmful to the engine.

The ugly = cheapy surround plastic body guard and bumpers - preferred the 70's bumpers and thin body chrome trims.

The 86's and 87's 300SDL were limited edition. Only 13,800 reportedly sold. Classic and collectible? Highly likely!

17th Oct 2009, 03:47

On Aug 15 I purchased a one owner '86 300SDL with 48,000 miles on it. White with blue interior. Have nearly all service records and it's pretty much in condition appropriate for a 23 yr old car with such little use. Interior even retained some of that new leather smell.


White paint somewhat oxidized.

A/C was not working at PU. Denver was in high 90's, Dallas 100 or more!

Fuel mileage from Denver to Dallas v. poor. Drove at a steady 70 mph, occasionally drifting into 80's due to the ease with which the engine gains speed. Power seemed OK.

Good stuff/issue resolutions:

My detailer is trying to save the original paint. Looks much better but still needs more work.

Aldo at European Auto Service outside Dallas replaced faulty sensor and 2 bottles of freon later... ice cold A/C!

He did this in 15 minutes after three days of my brother (a "professional" mechanic) and several of his mechanic buddies trying to fix problem.

My brother replaced the big fuel filter near the front of the cylinder head and there was a noticeable increase in throttle response. Aldo took filter out and filled it with tranny fluid and there was another noticeable increase in throttle response and freeway mileage went up.

Aldo swears by the tranny fluid in filter method of cleaning injectors and recommends it every time filter is replaced. Says "That's how they do it in Germany."

Aldo also replaced a heater valve. When I came hack for new wipers we noticed the inline fuel filter had black crud in it. Aldo determined it was from the 23 year old fuel lines, so new ones were installed along with the fresh wipers.

Car came with fresh brake rotors and pads all around along with new Michelin Primacy's. Tires are reasonably good riding but do make a bit of noise. Praise Aldo for talking me into new wipers, hit the worst thunder storm I've ever seen in Tucson driving home to San Diego. "But Aldo, I driving through west Texas, New Mexico, Arizona and Southern California. What rain?" The Michelins did quite well in the torrential down pour. It was raining so hard I could not see more than 40 feet at times.

The 300 SDL is a very nice, safe daily driver but it's a superb touring car. as smooth as my Subaru SVX, but not as quite. I think replacing the Michelins with Yokohoma Avid H4S's will improve the ride and they will be much quieter. Quite a bit more engine noise than I anticipated considering the cars reputation. Not that much quieter than the 5 cylinder 300 TD we have.

The alarm system is a mystery, there's very little info in the owner's manual. Still not sure what activates it but won't make the mistake of letting a car wash have my keys again. Took hours to finally shut the damned thing off. Have figured out how to shut it off.

The SDL refused to start last week. Turned key...nothing. Starter solenoid. Unfortunately you must replace entire starter, solenoids not sold separately. While diagnosing the starter problem came to realize the A/C compressor doesn't shut off. A hindrance to getting good fuel mileage and not good for A/C.

Got the car started by touching solenoid with my cane and it continues to work fine but will eventually have to be replaced. Got an estimate of $500 OTD from one shop!

Found more black crud in inline fuel filter, so I am hoping to resolve the issue with a catalyst or additive that will clean up whatever crud and fungi that may be in the fuel tank. Any recommendations?

Thanks for the previous comments. They've been very helpful for this new 300 SDL owner.


San Diego.

8th Nov 2009, 16:50

I am a new be as a Mercedes Benz owner. I really appreciate everyone's comments. I really like the W126 MB and was able to purchase a 300 SDL TURBO. I got it at a discount price because the previous owner could not get it to start after someone put agriculture diesel into the tank. He replaced the injectors but it will not fire.

Turns over great for me and I replaced both of the filters, but still it will not fire.

AC works fine. Sunroof works fine and everything else seems to work OK, but it will not start. It had the original owners manual, Sales agreement and repair records in the glove box.

How might I proceed to get it running again?



11th Apr 2010, 19:11

When I was 43 (1987), I bought a new 300SDL Mercedes. I had already owned a 300D and a new 1982 300TD wagon (actually owned two of them). I traveled a great deal in those days, and loved the diesel cars on the highway.

The 300SDL was the best car I ever owned, but at that time I assumed that things would just get better and better, and that the next car would be an improvement, as this car had been when compared to my previous MB's.

I sold the car to a business associate whose wife drove it for about ten years (it was only two years old when I sold it!). I had many other cars after that one, but none that I liked 1/2 as much.

In 2000 I bought another 1987 300SDL. A one owner car and a real beauty. I still have it and two other 1987 SDLs. I love them, and if you are willing to invest the $ in dedicated maintenance, they will serve you well. I still drive back and forth from Maine to Florida once or twice every winter in one of them. All but one of my six children is unimpressed, thank God one of my boys loves them and wants to keep them his whole life. We shall see.

I have owned the aforementioned MB's as well as another 300D I had in Germany when I worked in Europe for a number of years. That car was great, I bought it used with about 45,000 miles on it for + or - $1200. Used it for many years and sold it for a profit! It was a stick shift, and a lot of fun to drive.

Aside from that I also gave my wife a 1977 450 SL, had a 300SE? (also bought in Germany), a 300 GD (bought in Germany), a 280 SL (don't remember the year), a 1994 S350 diesel (great car, but not well engineered), and an S600 sedan. I think that is it. Well, the 300SDL's are the only ones I still have, and by far the best Mercedes I have owned. This is only my opinion and I'm sure many will disagree, but just making this endorsement for the record.

A Mercedes fan, Jim.