I'm currently looking at buying a 1982 300D Turbo Diesel with 200+K miles. The ad on craigs list said it won't start on its own, but runs fine once boosted from another vehicle. I went today and checked it out and sure enough by itself you turn the key and it goes "CHUR" one time like it tries to start but there isn't enough battery to it. We connected his Xterra to it, and it started within 15 seconds with little effort.

He's a young guy (by comparison I'm 37), and says he thinks it's the alternator but has no time to change it. He's asking $1000 for it. He's had the car the last 6 years, and before that his parents had it. He said they currently own 2 other new model MB's E-class.

I've looked all over the internet and cannot find a situation like this (WON'T start on it's own, WILL start with a boost and KEEPS running once boosted). I searched this forum and I found a similar situation but not exact and the culprit seemed to be either the alternator or the voltage regulator.

My question is, if the problem was the alternator, wouldn't the battery eventually die shortly after starting? And the battery had enough power to ring the door buzzer and (very slowly) roll the pwr windows up and down.

He drove the car up until 6 months ago, when he bought the Xterra. He starts it about once a month.

I checked the rest of the car, looks like no rust in the quarters or trunk. Under hood has considerable soot or some kind of black residue. Trans shifted hard from 1st to 2nd leaving his place, wasn't nearly as noticeable once the car warmed up. No whines that I could hear, could barely hear the turbo when it kicked in. Gray smoke out exhaust at start up but no smoke while driving.

I have never worked on a diesel, and am completely new to MB 123 models though I've tried to research them as much as possible. I'm looking for a cheap but safe and reliable car that my ex-wife can use a few months, then I can take back and continue to use as a daily driver while improving the overall condition of the car.

How difficult a fix up does this sound like, or should I move on? The car drove great once started, I was surprised at how well it did drive, though it's slow off the line til the turbo kicks in in 2nd. I know it's not a race car, but man off the line is slow (the ex will have to understand no pulling out in front of traffic).

Thanks for all your help.

Joshua

 

 

Once started these model diesels will run without any electrical power. The fuel injection is all mechanical. It will run until the fuel supply is interrupted -- that is how you stop the engine when you turn it off with the key. Vacuum shut off the fuel supply.

Sounds like you have a bad battery and maybe a alternator.

 

These Cars will quickly turn into a Money Pit if you cannot do or have more than an average Mechanical abilities and fortitude.

I suggest you do some reading and see the types of repair issues people are dealing with at the below sites.
Be sure to not that you need a Special Spring Compressor to compress the Front Coil Springs because the Springs are 3-5 times stronger than a comparable Gas Cars and note how extensive a job it is to change the Rear Wheel Bearings.

Check and inspect anything under the Car that is made of Rubber. The Rear CV Axle Boots, the Flex Discs on the Drive Shaft, the Trans and Motor Mounts and the Oil Cooler Hoses.
Removing the Oil Cooler Hoses from the Oil Cooler often results in stripped threads on the Aluminum Oil Cooler Nipples.

Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82
http://www.peachparts.com/Wikka/DoItYourSelf

 

More likely just the voltage regulator. Takes about 10 minutes to change with just a screwdriver.
You will need to replace the battery no matter what. Extended periods of discharge damages batteries.