hi everybody in a search to find a good car to modify for veggie oil i was directed to the early eighties benz diesels. as far as size, milage and value it seems best for my needs. I am a versed shadetree mechanic with older american cars and late seventies to early eighties japanese motorcycles. I have done major repairs as well as some pretty brave custom work. I am not to familiar with diesels. i have worked with everything from tractors to small 3cyl gennies but do not feel confident in wrenching myself.
cut to the chase
turbo vs. non turbo????????
what should i look for that has been neglected on these?
especially engine wise, most people seem to know to let the plugs warm and change the oil, valve adj? timing chain? and how often?
it seems the power windows and a/c have issues on every one.
are these easy fixes, easy to find parts? or should i price out some custom equiptment from the hot rodders circle
the diff seems small, will that be an issue?
I know diesels are prone to internal crud build up, whats a good internal cleaning stratagy?
is it a pain to prime the fuel? a friend ran me through it on an old tractor some 2 years ago.
how come the cruise control never works on these?
whats a good manual for both automotive diesel and the 300sd?
I am not afraid to take a car in but at the same time most mechanics around here should'nt be fixing a matchbox and right now i have my eyes on a very cool 1980 brown with 295000 miles ($1500). last owned by a firefighter and before that a mercedes parts store owner seems taken care of but i did notice a wire pulled off a relay on the right fender and taped up. ruh roh
thanks in advance and much appreciation.

> turbo vs. non turbo????????

TURBO!!!!!!!! Check the archives and count the turbos that have failed. Timing chains fail more frequently. Turbos usually seize, not shatter so chances are a turbo failure won't strand you.

The only mileage penalty from having a turbo is from driving faster than you should.

> what should i look for that has been neglected on these?

Valve adjustments, front suspension bushings, leather, cabin and trunk weather seals, transmissions, ...

> especially engine wise, most people seem to know
> to let the plugs warm and change the oil, valve adj?
> timing chain? and how often?

Valve adjustment every 15K miles. Replace timing chain when it gets close to 10* of stretch. Won't happen in your lifetime with proper oil changes.

> it seems the power windows and a/c have issues
> on every one. are these easy fixes, easy to find
> parts? or should i price out some custom equiptment
> from the hot rodders circle

Define easy? The fixes are easy, diagnosis is another matter. Most electrical problems are caused by dirty contacts in switches and junctions and/or corroded ground junctions and/or bad solder joints. A motor will quit once in a while but used replacements are easily available and don't cost much with a little shopping. AC and central locking run on vacuum systems. The pneumatic systems are quite robust but these cars are coming on their second cycle of rubber and plastic parts failures. In most cases it's easier and cheaper to fix these systems than replace them with electrical or more modern systems. Cars of this vintage don't take well to R134a conversions. Conversions work but will likely leave you wanting in Houston in August.

> the diff seems small, will that be an issue?

Haven't heard of one failing. Are you expecting a huge power boost from a veggie oil conversion?

> I know diesels are prone to internal crud build up,
> whats a good internal cleaning stratagy?

When conditions allow, drive with all the pressure your foot can apply to the pedal. Every year or couple of years do a Lubro Molly Diesel Purge treatment. Don't pour it into the tank. It's mostly Diesel fuel so it will be way too diluted to do it's job. The recommended way is to feed it directly into the IP and keep it recirculating until the container is about empty.

> is it a pain to prime the fuel? a friend ran me
> through it on an old tractor some 2 years ago.

Older models have a hand operated primer pump on the IP. The older design primer pump can leak. It's an easy and not-so-expensive job to retrofit a newer design primer pump. Newer models are self-priming.

> how come the cruise control never works on these?

MB didn't think anyone should use it

Usually the solder joints in the cruise amp develop cracks. Resoldering the solder joints in the cruise amp is the first thing to try.

> whats a good manual for both automotive diesel
> and the 300sd?

The Haynes manual will get you by. The MB factory service manual set is the best resource... well, assuming can't do a mind meld with Larry Bible

You didn't ask about transmissions. 150K is the typical life. 200K if you're lucky. Few make it past that. Some have converted their 300Ds to 4-speed or 5-speed MT using parts from a 240D or Euro 300D.

Sixto
95 S420
87 300SDL

hey thanks for the info
as for trans, knew that going in from some euro car savvy friends except the conversion, cool idea. the current apple of my eye has had a new one recently and feels strong. i may soon be a mercedes owner.

bought the car!!!!

You have just caught the dreaded MB addiction.
Pretty soon you will be searching eBay for another, then another.
You will be looking at any MB with, or without, a for sale sign on it.
You will post uncontrollably on this forum.
This addiction is incurable.

Our commiserations


Welcome to the Diesel clatter community
Tony

__________________
Tony from West Oz.
Fatmobile 3 84 300D 295kkm Silver grey/Blue int. 2 tank WVO - Recipient of TurboDesel engine.
Josephine '82 300D 390kkm White/Palamino int.
Elizabeth '81 280E, sporting a '79 300D engine.
Lucille '87 W124 300D non-turbo 6 cylinder OM603, Pearl Grey with light grey interior


Various parts cars including 280E, 230C & 300D in various states of disassembly.