Introduction, 1976 300D - PeachParts Mercedes-Benz Forum

zyewdall · #1 10-05-2010, 05:30 PM

Just got a 1976 300D sedan... for the price of a putting a new battery in it. Not bad...

It runs good -- engine is a rebuilt engine I believe. Non turbo. Doesn't really like starting below 50F or so, but it will start. Transmission.... I have to manually shift it between 1st and 2nd and drive to get decent performance --but I do that on brand new automatic transmission too, so maybe it's not anything wrong with it. It looks like there is some good info on here on adjusting it though.

It has a vegetable oil system already...put in a few years ago by a Colorado school of mines class. I need to figure out the controls.. it's got some thing that senses the temperature and won't let you switch till after it's hot enough, and also runs it for a few minutes after you switch back to purge the oil from the lines before shutting the engine off. I've heard it running on veggie oil back when they did it, and it sounds like a gas engine while idling... no diesel clatter.

I also have another project with a mercedes diesel engine... a 1967 landrover 109 that's getting a 1985 5 cylinder turbodiesel. I have the extra transmission from that engine, that could go in this car if it's transmission really is bad, maybe? If the '85 had the same auto transmission as the '76

brownrice78 · #2 10-06-2010, 04:40 PM

Cool car. Glowplugs or possibly low compression will lead to hard starts on cold days. If the engine was really rebuilt, then compression shouldn't be an issue. Junk the vegetable oil setup. That setup will ultimately lead the car to an early death because the oil clogs the injection pump.

Diesel911 · #3 10-06-2010, 05:46 PM

Veggie can also cause sticking Piston Rings which can cause low compression which can cause hard starting.
If you live in the USA you can get a compression testing kit from Harbor Freight stores for $30 or so and less when it is on sale.

To improve your starting you could update your Loop/Filiment type Glow Plugs to the Pencil type if you do not already have them installed.

If it turns out your compression is low you might try Pulling the Inectors or Glow Plugs and pouring in some Marvel Mystrey Oil and letting it soak for a week or so. (Afterwards do an Oil Change.)

Or some have claimed changing to Synthetic Oil over the course of several hundred miles will free the Piston Rings.
Something all off the above should be here:
DIY Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82

http://www.peachparts.com/Wikka/DoItYourSelf

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