1987 Mercedes 300D

[Tom W]

I'm looking at this car. Owner put homemade bio in it and it quit running. 190K miles, compression good, will run on reg diesel but leaks at pump connections. Mechanic says seals ruined by bio. Anybody have any idea how much it would cost to rebuild fuel system.

 

[SEmerson]

When you say pump connection where do you mean? I has the 6 right?

 

[Dieselnut59]

Ironic! I am going to look at my neighbor's car just like what you mentioned. His is the 1987 300D also. My mother had a 1987 300SDL. Great car. I am not sure if his is the 5 cylinder or the 6. Mama's was the 6. This guy only wants $1000 and he is the original owner. It has been sitting for 5 years because it would not cut off when you turn off the key. Mama's did that and it was a vacuum solenoid.

As to your question, I have heard bio will "rot" fuel lines if they have been previously run with regular diesel. It also acts as a "detergent" and will flush impurities out of your fuel system, in turn clogging the fuel filter and possibly the pump, lines and injectors. If you are getting a good deal on it and it runs on regular diesel, but just leaks, it is definately a keeper. I am not sure how hard the pump seals are to replace, but the lines are not bad. I will let you know if I get my neighbor's car. I am going to look at it this week.

 

[JoeBioDiesel]

Dieselnut, if you replace the vacuum shutoff solenoid on that 300D make sure you have a way of stopping a runaway diesel. If you miss the hook with the solenoid inside the pump the engine will take right off. Be prepared to kill both the fuel and air to that engine.

Joe

 

[Tom W]

SEmerson it's a 5, it's on E bay and the owner says the leak is at the injector lines coming out of the pump. I don't know if I want to get into this - the bid is about $2200 and I would have to haul it about 500 miles.

 

[Schlickenmeyer]

Try Benzworld.org - Mercedes Benz Discussion Forum forums

A lot of good info there, I have an '81 300d and I love it.



Good luck!

 

[JoeBioDiesel]

Another good one is MercedesShop - Mercedes Benz Parts and Technical Information

 

[Mrudolph]

Dieselnut, if you replace the vacuum shutoff solenoid on that 300D make sure you have a way of stopping a runaway diesel. If you miss the hook with the solenoid inside the pump the engine will take right off. Be prepared to kill both the fuel and air to that engine.

Joe

The 300D has a fuel shutoff lever on the top of the injector pump labled "STOP" for use if it fails to shut off with the key.

 

[Misenheimer]

1985 was the last year for the 5 cylinder 3L engine. 1986 was the first year for the 6 cylinder engine and a whole different animal. The later 350SDL and 300D had aluminium heads with basically a different engine design. The parts for the 5 are cheep compared to the 6. My 85 300sd is less expensive to repair, more durable and easier to work on than the American cars.

Repair window regulator on 96 Jeep $87 in parts 85 Mercedes $4 for the same broken part.

Injector lines that are over tightened will leak.

 

[Dieselnut59]

The 300D has a fuel shutoff lever on the top of the injector pump labled "STOP" for use if it fails to shut off with the key.

That is what happened to my mother's when the cut off solenoid quit working. She had to raise the hood and mash the "stop" lever to kill it. I think that is what is the problem with my neighbor's car. I am going to look at it soon and will post more. Nice thing: He is the original owner, it was his 4th Mercedes diesel, he always had it serviced at the dealer and he seems to be a sincere guy.

 

[Tom W]

Followup on original post. Seller took car off EBay - he lost the title. Thanks for the replies, I learned a lot.