Hi, new poster with 300 SDL questions - PeachParts Mercedes-Benz Forum

#1 07-26-2007, 03:42 PM

Hello, new poster... just bought my first Benz for a bio diesel project....I'm having a hard time finding a shop....looks like the closest ones listed here are 3 hours away. I'm in the NW corner of North Carolina, zip 28631. Any help finding a shop would be much appreciated. The new old car is a 1986 300 SDL with approximately 230000 miles on it . It had been a one-owner car that spent most of its time in Southern CA, about 7 years ago the owner moved to Charlotte NC. The body is in great shape except for sun damage.
My thinking had been that I just wanted any kind of road worthy diesel to run home brew bio diesel in…. didn’t know I was going to fall in love with a 21 year old car….

Here is what’s been done so far:

1) Changed air, fuel, oil and transmission filters/fluids
2) Brakes checked and fluid flushed
3) Modulator valve for transmission replaced I spoke with Roy from the Mercedes Shop and he says the transmission valve needs to be cleaned. Local shops don’t want to mess with this….
4) The front and rear shocks have been replaced

5) New tie rods and a front end alignment are set to be done locally next week

6) Ran a bottle of fuel treatment through it

What the car still needs:

1) New or rebuilt front seats…sun damage plus some of the seat motors are fried. Plan A would be to find a used set in the tan color. I have located some seat bottoms that, if I understand correctly contain the motors…. I could have the seats fix and re upholstered. Also, which model cars would have seats that would fit?
2) A good paint job
3) A visit to a mechanic that knows the vacuum system, transmissions and engines on these cars.
4) Cooling system flush…. The car runs in the low 80’s most of the time but I live in the mountains and when I go up a long steep grade the temp goes past 100… one of the shops had said they would flush the radiator and change the thermostat but then “got to busy for that job during the Summer busy season”…. I need to know if it’s worthwhile to just flush the system with out the thermostat being changed at the same time and if so what type of antifreeze to use
5) Rear passenger window needs a new part…. can’t remember what the seller said it was… a gear??? If it’s just one common thing that goes wrong I’d like to just order the part ahead of time. If it could be several things, the window could wait.
6) Cruise control does not work. I’ve read that this is a common problem with this year and likely not worth trying to have fixed…. True?
7) Odometer doesn’t work….would this be a hard fix?

That’s my list for now any and all suggestions welcome. Thanks

TX76513 · #2 07-26-2007, 03:55 PM

First Welcome for stumbling upon us!

Needs
1. There are plenty of parts available take your time a find a good deal - there are many 126's being parted on the forum.
2. Can get pricey
3. You need to learn the vacuum system. 20+ year old lines should be replaced. I replaced mine a little each week, cleaning or replacing as necessary.
4. A search on the forum for "citric acid flush" and "anti freeze" will give you days of reading

5. You need to "go in" and take a look. Cramped, but not a complicated device.
6. Some people have re-soldered the cruise control amp. If you like/need cruise it's an option
7. Forum Member Diesel Giant did a great (pictures)tutorial on fixing the little gear for the odometer.

You will with a doubt find all sorts of little quirks and they just need to be dealt with. A good investment is having an oil sample analyzed ($22) it will give you and better look at the motor. Google Blackstone Labs

They are fabulous cars and you will fall in love with it an become addicted like the rest of us

that own them

#3 07-26-2007, 08:17 PM

Thanks, just back from an evening cruise and the transmission has been shifting into overdrive on it's own again....maybe the new fluid has cleaned up the transmission valve mount "thing" enough to make that keep happening. The car is also making it up steeper grades with less downshifting since I ran the fuel treatment through the last tank...
I'm expecting a call back in the morning about a set of seats that everything works on and are in "pretty good" condition. Seller is make a closer inspection for me. I'm a happy camper!

Jim B. · #4 07-26-2007, 08:26 PM

Check the "Good MB shops" section for North Carolina and see what come ups. You might get lucky.

I would only use MB fluids on these cars, it is a good idea to use what the owner's manual recommends and not short cuts in these cases.

If the radiator on the car is original it might be time to replace it. The OEM radiators had unreinforced upperhose necks which after time tended to crumble. The Behr and Nissens replacements are good, without this problem.

#5 07-26-2007, 10:34 PM

one good advice is that you HAVE to learn how to fix your own car.
This forum will help you do that, all the information is here and the people are great and helpful.
If you don't, that car will be a gigantic money-pit...
be patient, parts like front seats etc come up when you least expect them.
also, be careful brewing biodiesel. some people don't do it right and the acidy biodiesel they pour in their car messes up the injectionpump. That's what my diesel parts and service- shop told me... they rebuilt a lot of injectionpumps.
goodluck!

Hit Man X · #6 07-26-2007, 11:12 PM

At 20-22 years, you probably just need to go ahead and buy a new radiator to install along with a new thermostat with aux fan switch. Test the fan clutch too. Use MB or Xerex G05 coolant only.

You're going to need hoses and a belt too. I'd swap brake hoses too, they're dirt cheap. If you have the old style vac pump, make that a high priority to swap SOON.

Transmission does not have overdrive, it's direct (1:1) for 4th. Service the unit... drain the converter and new filter. Top off and add some Lubeguard to help with sticking valves in the body. Adjust TV (bowden) cable. Check vac drop from BLUE UFO deal (driver fender) down to the trans. Adjust accordingly.

If you're going to swap tie rods, just do the ends... save yourself cash. Do the drag link, rebuild the pitman arm, and consider the upper control arms to tighten the entire front end up. Then get it aligned.

Aside from that, you can read for days with the information posted here on the 603/SDL.

#7 07-26-2007, 11:19 PM

at 230k... I'd say lower ball joints and maybe track rod ball joints (don't know the correct name for them, only that they're $150 each at the dealer
and of course the compressor/ clutch is nearly dead, flex discs are getting dry, most rubber on the car starts to need some teflon spray to stay alive, and it needs a purge badly

Hit Man X · #8 07-26-2007, 11:21 PM

I agree, the suspension is pretty much done.

#9 07-27-2007, 12:01 AM

these cars go for a million miles though

Hit Man X · #10 07-27-2007, 12:04 AM

Quote:

Originally Posted by henrydupont

these cars go for a million miles though

What about 40mpg?

lietuviai · #11 07-27-2007, 12:05 AM

Quote:

Originally Posted by henrydupont

these cars go for a million miles though

That's what they say about the W123's.

#12 07-27-2007, 12:09 AM

Quote:

Originally Posted by lietuviai

That's what they say about the W123's.

sorry I thought any benz would go for a million miles...

probably only the non turbo 300d really will... in a warm climate with a very careful driver

#13 07-27-2007, 08:08 AM

Wait....so the nice man selling this car was less than honest when he told me that all I'd have to do for the next 20 years is keep filters/fluids changed and maybe replace the tires after another 100000 or so miles

Hit Man X · #14 07-27-2007, 09:27 AM

Tires that last 100k?

probear · #15 07-27-2007, 10:07 AM

Quote:

Originally Posted by Hit Man X

Tires that last 100k?

My Mich HydroEdge are guaranteed for 90K miles. Personally, I'd bet they go only 60 to 70.

The thing to remember, even at 230K miles that is only a little over 10K a year. Most of the parts are more age worn than mileage. Replace them and you're good to go for quite a while.

I've put 39K on mine since Sept 2005 and it's still running great.