I need your opinions on a W115 1975 300D - PeachParts Mercedes-Benz Forum

79Mercy · #1 07-20-2009, 10:37 PM

IM going to go look at a 1975 300D later this week. It has less then 200K and has had 2 owners. The owner tells me the body is in excellent shape, as well as the engine and auto tranny. It has vacuum issues, and has a bad window regulator. More info to come......

What do ya'll think about it knowing what you know?

Shawn T. W. · #2 07-20-2009, 10:59 PM

Sounds good enough to look at . . . are there any service records? Too bad it doesn't have a manual tranny . . . remember to look close . . .

TylerH860 · #3 07-20-2009, 11:06 PM

I drove a 1976 300D many years ago (a year or two before Ol' Turbo and this forum) and loved it. They were asking $900 for it, and it was the original elderly owners. Unfortunately it had more rust than I wanted to deal with, but it drove fantastically. Its very simple and elegant.

Take pictures and report, of course.

compu_85 · #4 07-20-2009, 11:17 PM

The shifting on that car is totally controlled by vacuum, so leaks can make the trans act up.

It will also have loop glow plugs if it's as it left the factory... be prepared to wait a long time for the glow plug light to go out. This was the first benz diesel with a wait to start light and a "normal" ignition key.

-Jason

79Mercy · #5 07-20-2009, 11:22 PM

I instantly fell in love with the W115's after I drove kevin's(kpmurphy) 1970 220D with a auto tranny. Yeah it was a bit under powered but it drove GREAT. Really once you go going its was fine.

There isn't a control rod going to the tranny?

If need be I can manually shift the transmission by moving the shifter.

I'll report back, of course i'll get pics.

yellowbenz · #6 07-20-2009, 11:37 PM

Vacuum control on the tranny? My 78 300D has mechanical control (adjustable push rod. Surprised the w115 had vac control.

Actros617 · #7 07-20-2009, 11:41 PM

I dont think that the W115 tranmission control by vacuum, its mech, it was vacuum control when the W123 and W126 came out.

79Mercy · #8 07-21-2009, 12:02 AM

^^^thats what I always thought

dalek · #9 07-21-2009, 06:56 AM

I myself can't remember; I sold my old transmission long time ago. Old and seized engine is still here. One of these days I might tear it apart. I wonder what is different between it and the turbo engines besides the oil squirters. In fact, I wonder if the old engine could be drilled for squirters...

To the OP: just make sure the vacuum pump is ok. In fact, run a clear/translucent hose to the valve cover. When these pumps go, they can take the engine with it. And that is the reason the original engine is in my storage and I ended up doing the turbodiesel upgrade. Incidentally, even with the original engine I would do 80mph.

pizzachef · #10 07-21-2009, 07:55 AM

Pull up the carpet and check the floors for rust. Also the wheel wells.

Then turn on the blower and make sure the fan works (not the a/c fan, the heater/defrost fan) and doesn't make any noises like its dying. They're supposed to be a huge pain to replace.

Look at where the steering box bolts to the frame/body in the engine bay and also behind the front drivers tire. If the mount is broken, it can be fixed by welding in some plate, but if you don't weld that can be a kind of pricey fix. My $2500 car gained $1000 in "value" after I had that repaired

Look at the front and rear windshield seals, if they're cracked and dry, water will leak through. I replaced my front glass, but I can't find any place that sells rear glass for this car, so you should probably check for cracks in the rear glass too

I don't think there's a whole lot else that's specific to this body. Same mechanical checks to the engine. The IP has its own lubricating oil, so you could ask if its been changed. And the air filter is an oil bath filter. You could check or ask about the frequency of that oil change/filter cleaning.

Glow plugs aren't that big of a deal. I swapped mine for the pencil type and it helped in the winter, but summer time, its hardly a noticeable difference.

good luck!

dalek · #11 07-21-2009, 08:46 AM

Quote:

Originally Posted by pizzachef

The IP has its own lubricating oil, so you could ask if its been changed. And the air filter is an oil bath filter. You could check or ask about the frequency of that oil change/filter cleaning.

How to check it?

pizzachef · #12 07-21-2009, 09:22 AM

Quote:

Originally Posted by dalek

How to check it?

There's a fill/level check plug in the side of the IP. Can check the oil level there, but you get a little messy doing it. Oh, and there's the red OEL cap on top the IP

The top of the air filter comes off with the long tube (leading to the intake) attached, so you have to loosen the clamp at the end of the long tube and then undo the clips holding down the lid. Then the filter lifts out (can be messy) and you can check the oil level in there...and probably see the level of nastiness in that oil.

compu_85 · #13 07-21-2009, 10:01 AM

Hm, I guess I was confused about the trans then

My friend's 76 300D uses engine oil for the injection pump. Were the 75s different?

-Jason

pizzachef · #14 07-21-2009, 10:06 AM

Quote:

Originally Posted by compu_85

Hm, I guess I was confused about the trans then

My friend's 76 300D uses engine oil for the injection pump. Were the 75s different?

-Jason

Hmm...I forgot this is a 300D. Mine is a 240D. I don't know when they switched to having engine oil lubricate the pump. I though it would have been in '77 when the w123's started, but honestly I don't know.

bluebenz · #15 07-21-2009, 10:26 AM

On my 76 300D the IP is lubricated by engine oil, I think it's the same for the 75.

As for the glow plugs, the longest I had to wait for the light to go out was 40 seconds, on a 40F morning, so it's not too bad!