well, acquired a tow-home '83 300SD w 280k miles... my first Mercedes! price was right, body decent, last ran in 2014. got it to fire up long enough to drive it to the car wash for an engine wash and remove the barnacles. swore off diesels after putting 140k miles on veg oil with a '91 Jetta converted to WVO. got drawn back into them thru this rescue mission on the Mercedes.



Done List:
oil change
air filter
fuse box rehab/cleaning contacts
oil cap jiggle test: passed very nice
checked turbo bearings, just a slight shake, spins nice, no bad intake vanes
odometer gear rebuild
dash dimmer bridge fix
repaint gauge needles neon orange
clean sunroof tracks
remove crumbly hood insulation



To Do List before hitting road:
re-attach vac line to aneroid and check nipple for free flow
Fuel filters
drain tank + filter
adjust valves
rebuild injectors + check timing
get HVAC blower working
get HVAC controls working

To Do as time permits:
Passenger window motor locked
door locks inoperable
change emergency flasher switch (funky now)
reglue peeling wood trim
sagging drivers seat
electric antenna


-dan

Congratulations. Sounds like a nice project car. You will find the members on this forum to be very helpful with technical advice and parts when needed.

i've been trying to decide which Mercedes list to spend my time and energy with... i'm active on Samba for VW Vanagons and that list is great with strong technical people and is polite. seems there's a fair bit of technical expertise on peachparts.

-dan

made progress on the HVAC today... removed blower and rotor was totally locked up. system still dead with a test fan. removed button climate control and repaired 2 burnt PCB tracts on pin 10, likely toasted due to over-current. test blower now steps thru different speeds and auto ramps up and down. new Bosch blower motor coming ... got last one at ********.

pulled fuel sender, gunked up and no way it would move. cleaned it up, broke the copper ground wire and replaced with a tin coated one. sender and low fuel light now work. tank drain next along with filter changes. smells like varnish and is cloudy.

It could just be that the window switch contacts need to be cleaned (switch comes apart don't loose the ball bearings, springs and rockers). I scrape them with a small pocket knife. Others say not to do that and use some other cleaning method. Your choice.

I don't know if the SD front doors are the same as W123 doors in that the W123 doors have a terminal/junction block where the Motor Wires connect held in with screws. I had both of the 2 screws back out and tightening them returned fixed the no go issue.
It is also a convenient place to test the front window motors. because the wires are right there. Not hard to connect some jumper wires to the motor wires and apply them to a Battery and see if the Motor itself and the regulator are working.

Unfortunately the read doors don't have any terminal blocks on the W123.

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84 300D, 82 Volvo 244Gl Diesel

Check the oil cooler lines too. On the sagging seat, the base is interchangeable with the later ones (89-91 I think) but those have an extra spring so they are way more durable. They are not too hard to take apart once you seen how they are assembled.

the dome light dims when working the window switch so at this point i'm assuming a locked motor.

When I had the locked motor it was because the bearing at the rear of the motor had stuck onto the shaft.

Unfortunately due to the bearing retainer being staked in to the bottom of the housing I had to pull the shaft and bearing through the spring tabs of the bearing retainer bending some.

I had to then pull out the bearing retainer and bend it back into shape the best I could.

Now I know that I could likely have avoided that by spraying penetrating oil down where the bearing is and simply waiting to see of it worked to the out I could pull the shaft out of the bearing and leave the bearing in place.

I don't have a picture of it but there is actually a hole on the bottom side of the bearing area in the motor housing were spray the lube in behind the bearing.

But, of course your issue may be different.

There is several motor take a parts and window regulator issues in the Repair Links
Fast navigation Fast navigation Do It Yourself Links

Attached Thumbnails

   

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84 300D, 82 Volvo 244Gl Diesel

thanks for the fast nav links... hadn't come across those!! very useful.

tank drain tomorrow! i think i'll suck it out from the fuel sender which i just had out for rehab. there was enough gunk in there to make me think the tank screen will be sludged up and hold back some diesel. Question... is the sludge in the interior of the sender correlated with the amount in the tank? or does it somehow accumulate more than the tank (hope hope).

-dan

Don't forget a transmission fluid & filter change. Differential, too.

"last ran in 2014" it is entirely possible the sludge is from stuff growing inside of the Fuel Tank.
The stuff can be killed with a biocide. Not sure I am spelling it correctly Biobor can kill it and stuff like Startron (startron makes more then one product so you need to sure you get they correct one) uses an enzyme which is supposed to break up the organisms into small enough parts that they safely pass through the Filters.

Note even if you removed the Fuel Tank and cleaned as is often done you still need to treat the infection (so to speak) because it is still in the fuel lines going from back to front.

From my notes (more on the subject would be in the repair links):
STARTRON
Algae Clogged Filter Pic StarTron WORKS !

Biocides Startron, BioBor, BIO KLEEN
Diesel Power "Diesel Clear" or Starton diesel fuel treatment are the best products to use.
Biobor will CLEAN the tank, but not reconstitute it into the fuel for burning, and WILL plug up your tank filters/screen/etc
http://mydieseldoctor.com/FAQ.html
http://www.thedieselpageforums.com/tdpforum/showthread.php?t=23293&page=2

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84 300D, 82 Volvo 244Gl Diesel

that sludge was tough to dissolve!! my parts washer solvent didn't do much, only carb cleaner seemed to liquify it. given that, while i would love a sparkly clean tank, i wouldn't mind if the goo remained adheared and slowly dissolved over the next years of driving. i'll treat it with biocide but i don't want to release a whole bunch at once. the photo links in the StarTron "Algae clogged filter" thread are all defunct, i'd be really curious as to what that did in the tank. according to the text, it cleaned up.

i'll be keeping spare filters in the trunk to be sure! i'll add trans and axle flush to my list after i get it on the road to see how worthy it is.
-dan

well, pumped the tank out today from the fuel sender hole. about 4 gallons of very old fuel in there. on the bottom of the tank was about 1/8" of dark chocolate colored tar. no rust on bottom and the goo was very smooth like the hot chocolate fudge you pour on ice cream. no grit or chunks. i'm THINKING this will dissolve with some additives and clean fuel over time. yes? no? fuel outlet screen will be changed.

got the passenger power window fixed, lower bushing of motor seized up. can be removed pretty easily without taking the regulator down. window was stuck in the up position. had to pop the cover off the gear case in order to mesh the top bushing.

easy fix on the door lock pump by just removing it and hitting it with 12v in various configurations on the 3 pins. motor whirred and then worked when plugged back in. each door lock works!!!

after several bulb replacements, all interior, puddle, and instrument lights are working. except for the trunk as there's a short in the lid wires that blows the courtesy light fuse.

it's coming along. much left to do.

Was PO running odd additives or poorly filtered biodiesel/WVO that could cause the tar-like deposits?

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Greg Schwall

1983 300SD - 465,000 miles

that was exactly the issue on mine... had to use a small puller and heat to remove the round bushing from the shaft. tried to remove that finger clip so i could re-insert it over the bushing but it wouldn't budge so i just bent the fingers back over with a socket. they are loose but time will tell if that is an issue. that window is now the fastest, smoothest window of the 4.


-dan