So I bought this 1986 300SDL Turbo - PeachParts Mercedes-Benz Forum

aroohk · #1 11-09-2005, 04:33 PM

So my aunt and I (a college science professor) wanted to try the whole bio fuel thing. What better car to use than a good ol diesel benz. It started out looking at 1985 300SD's and 1987 300D Turbos. Since I will be driving this car, I really wanted a car with ABS. Well... what we came up with (on a fluke) was a nicely maintained 1 owner 1986 300SDL Turbo. silver/blue power rear seat, VERY original car. 409091 miles on the odometer, with a tranny in the past two years and a front end rebuild within the last year. All the power stuff worked/works on the car. The car had been sitting for quite a while and when the former owner started it up, he noticed 'something' so off to his high prices mechanic it went. He ended up buying a MINT 1990 350SD that his mech. had up for sale cause he was told the SDL needed a head gasket. So we picked up Inga (thats her name) for 1076.00 and were going to ship it from palm desert, ca to my home in orange county, ca (gotta love AAA Premier Service). They were convinced it was a head gasket, but since the temp guage never showed any sign of getting anything above normal, i was going to drive the car 20 miles slowly, and use one of my 100 mile tows. Well the car was driving GREAT, and so I safely and slowly drive the car the 110 miles home and the temp gauge never went above the mid point. There was NO white smoke out the back and the coolant light never came one.

Since then I have put close to 500 miles on the car, and it all seems fine. I checked my fuel econ on my first 1/2 tank and got just under 24mpg. I talked to two mechanics, and they both said it didnt sound like a head gasket, as there would be other tell tale problems. The coolant level is fine, the oil is fine (badly needs a change) and the car performs like a 300SDL should.

Any advice or input as to what I should look for, or just keep driving it and being watchful of the temp gauge.

At idle with the AC on, the temp gauge sits just above 80. At idle in traffic, the oil pressure gauge sits right at 2 or just above.

I dont know a lot about this car, and would love to know a lot more about what I bought. I also own a nicely tastefully modded 2000 BMW 323ci coupe, and have fallen in love with my 3800lb tank. I live in southern cal, and could not be more pleased cruzing along in traffic in that solid 126 chassis. It is sad to say that the newer S Class cars have NOTHING on this car.

So guys... give a newbie a hand and shoot of some input, suggestions, and specs on my new car. I will post some pictures when it gets an appropriate detail this weekend. The only problem is the rear power seat is not working (either motor, relay, fuse, or switches...) and the sunroof made a odd/loud sound... so it is staying closed till i can get it checked out. And the teflon clip that guides the left rear window up and down broke (already have two spares sitting in the trunk waiting for my brother to install the repair kit).

I had the old perfectly working becker out and replaced with a spare panasonic cd player i had sitting around. Ahh the modern age...

Also, anyone know if I can pull apart and clean the power seat switches. They work fine in ALL positions, but they are kind of stiff. And can you replace the lights that illuminate the console window switches and the dash rocker switches. Some light up and some dont...

The only issue I had this evening was hitting a CA pot hole and the radiator light turned on, and then off in like 2 miles. I pulled over and checked the coolant level and it was right where it should be. I think the sensor just got tripped by the bump.

OK... thats enough for now, and feel free to message me here or email me at aroohk@gmail.com.

turbodiesel · #2 11-09-2005, 04:41 PM

If you're not loosing coolant, and there is no cross-contamination between oil and coolant, just drive it and enjoy it.

Ra_ · #3 11-09-2005, 04:47 PM

I also recently bought mine, to dabble with alternative fuels.

After experiencing the car, I am now far more interested in MB's, than in alternative fuels.

I'd still like to try them...
but I'll get another car for that.

Dervman · #4 11-09-2005, 05:12 PM

Welcome to the Forum and congratulations on your purchase.
Sounds like you may have made a good deal if the Head Gasket diagnosis was a false alarm (I certainly wouldn't want to suggest that the "problem" was created just to encourage the previous owner to buy another car

).

Keep a close eye on the Temperature Gauge - your readings are perfectly normal right now. After using the car and leaving it overnight, check the Top Rad Hose in the morning. If it is soft and pliable that is fine. If it is hard as a rock, then you may have a potential Head Gasket or (worse) cracked head.

Check for oil in the coolant and coolant in the oil.
CHANGE THAT OIL NOW with a good 15W-40 Diesel rated oil. If your present oil is just black, that is normal with a Diesel. New oil will turn black after only a few miles.
Change the Oil Filter and the two O-Rings on the Filter Stem - not included with the filter but about 10 cents each from a dealer.
Change all your other filters unless you know they were done recently - Air Filter and both Fuel Filters.
If in doubt about when it was last done, Flush the Cooling System and re-fill with M-B Coolant or Zerex only (should be pink not green).
Check the condition of the Drive Belt and Tensioner. The Tensioner is a known weakness that needs replacing from time to time.
Look at the Vacuum Pump (front of engine below Power Steering Pump). If it has a smooth front cover it is an original. If it has four screws on the cover then it is the updated design. The original pumps if they fail can cause catastrophic failure of the engine so most people replace them as preventative maintenance.
Check all the fuses for any corrosion and replace any that appear bad. Flaky Fuses are the source of many electrical gremlins.

Good luck, these are GREAT cars and properly maintained will last a loooong time.

Habanero · #5 11-09-2005, 05:17 PM

I assume you know the 603's reputation for cracking heads? If anything were wrong with the head, it would probably be a cracked head vs a head gasket. When the engine is cold in the morning, open the hood and squeeze the upper radiator hose. If it is hard, you very likely have a cracked head. Coolant loss will usually accompany this condition, so if you have no coolant loss you probably have nothing to worry about. I only bring all this up as the condition of the head/head gasket appears to have already been suspect.

Habanero · #6 11-09-2005, 05:17 PM

Man, I didn't think I took that long to type...

Plantman · #7 11-09-2005, 07:03 PM

Quote:

Originally Posted by turbodiesel

If you're not loosing coolant, and there is no cross-contamination between oil and coolant, just drive it and enjoy it.

What he said...........

aroohk · #8 11-09-2005, 07:15 PM

OK here is the deal...

I have the updated vacuum pump (four bolts on the front...YAY).

I am also very lucky I have a good friend who owns a foreign car shop here in CA.

I am going to have one of this techs do a complete filter service on the car...Although the air filter looks almost brand new. Literally EVERYTHING on the car works, save for the left rear window (I have the small rebuild part and its getting installed Friday), the Sunroof works, but makes odd noises (I think the guides need to be replaced and the mech. cleaned) and the rear power seat is inop. I highly doubt it was every used so I think it might be frozen or just a bad fuse or wire connection or something simple.

Otherwise, I have falled in love with the car. I got just under 24mpg on my first tank, and was blown away. Not a lot of highway and typical heavy footed diesel driving.

The AC blows ICE Cold and the Temp control/dampers/stuff works as it should.

The mechanic that was selling this car for his customer, was honestly tired of seeing the car every 6 months. The PO would not just do simple repairs, as it was an all or nothing deal for him. He pulled the file and said that in the last 3 or so years the guy has spent close to 9 grand on the car. So its not a 10 in looks (inside or out) but it was REALLY well maint. I dont have the service file on it, but the tech said to call if I ever need anything. He saw some 'signs' of what might have been a head gasket issue, but the PO saw this 350 that was for sale and just jumped at it. The PO gave him the car and I picked it up for a grand!

If you want to see pix of the car, you can check it out on the ebay link that is still active...

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4584262055&sspagename=ADME%3AL%3ARTQ%3AUS%3A1

Thanks for the advice guys, and I am laughed when I took my mom for a drive in the car. She looked at me and said she would sell her Explorer (she LOVES her SUV) in a heartbeat to drive a Diesel Benz. So I might be looking for a 300TD for her or a nice 199x 300D or E300 Diesel for her.

Last question... anyone know where to get the nice bosch euro lights from? I might try my part supplier here, but I dont want to pay a fortune...

Thanks
Aaron

Hit Man X · #9 11-10-2005, 12:00 AM

I spoke with ya on Yahoo IM earlier, sounds like you too found a "diamond in the rough"

The L is a great cruiser with lots of room.

Charlie_M · #10 11-10-2005, 12:26 AM

She's a beaut!! I think the SDL is a wonderful car. You got a nice color combo and looks like it was well cared for. Best of luck with it.

Charlie

dieseldiehard · #11 11-10-2005, 01:27 AM

Nice find! I like the smaller 124 chassis with the same engine, just because I like a smaller car, and I like to go fast

Everything said previously is right on the subject.
I suggest using a good synthetic oil to keep the lifters from plugging. In So Cal 15W40 is fine. Maybe 5W40 or 5W50 Mobil 1 if you choose but the heavier 15W40 is fine for a warmer climate.
For Euro lites, sounds like you deserve them if you have a good car you need to see properly (and be seen!)
Hellas are the best but there are Depo's on eBay at times and they are not quite as fine as Hellas or Bosch headlights.
Check PUMA, you may have to call them if the info isn't shown on the web site: www.puma-access.com or (440) 498-0638

dieseldiehard · #12 11-10-2005, 01:30 AM

Oh yes, the PO will regret buying a 350 someday, just wait! he'll wish he has the SDL again!

Ara T. · #13 11-10-2005, 03:47 AM

Looks like a fine car, especially considering the mileage. We have one of these in the garage. It's too big for my liking, and it is sluggish off the line (needs an ALDA adjustment). Also unfortunately, it was in an accident before we got it, and the panels are straight and everything but it has a mediocre paint job when you get up close to it, and the interior (mostly the rear) rattles and squeaks especially on rough roads.

Someone let me know if the rattling is a problem with our car or a problem with W126s all around. So it's kinda annoying to drive sometimes. But I will say that it has waay more power than my W123 after the turbo spins up. The brakes are also insanely good and it handles well despite its size.

aroohk · #14 11-10-2005, 03:44 PM

The creaking sound in the bottom of the door panel rubbing against the plastic door sill piece. I am going to line the bottom of all my door panels with felt strips to keep this to a minimum. I am pretty sure All 126's were subject to this as every 420, 560, and 300 I have driven has done it when they get older. It seems like it is an issue of the door panel not fitting as tightly as it did when new and the two pieces just rub and make noise!

I will let you know if it fixes it on mine and you can do the same for yours!

Aaron

Plantman · #15 11-10-2005, 05:16 PM

The car looks nice.

I've spent 2 years getting mine almost perfect. It got painted a few months back and looks new.

I'm send it in to get the seats redone and Iwill be done.

I averaged almost 30 mpg hwy on mine when I used it a lot.

great car and comfortable as hell for a big guy like me.