Converting a Mercedes Benz 300D to run on: biodiesel, SVO, and WVO

I recently bought a 1983 Mercedes Benz 300D, with 327K miles and wanted to convert it to run on veggie oil. I know that these cars are built to last thats why I got an older one. I have some mechanical skills working on a older honda but never a diesel car.

I have a couple of concerns- first off when I start it up the exhaust blows smoke. Is this normal? (I have never owned a diesel car before) If not what can I do to help remedy this problem. Secondly this car doesn't have a whole lot of power when I start from a stop acceleration is slow even when I the put pedal to the floor. Does anyone out there have a similar model that they have converted to run on SVO and have seen improvements in performance?

For the biodiesel people out there: Do you recommend boiling the fuel tank to kill bacteria? Any other tips for set up for this vehicle would be appreciated.



Smoking Mercedes

Hey Chris,
A while back, I invested 2 grand to buy a 1983 300D Turbo Diesel with high mileage. I had a little fun driving it, and then the engine blew. I thought it would be a good investment... well yes and NO. I mean it is a MERCEDES. I will never sell it for what I invested, but I had the engine rebuilt and it ran, but there was so many problems I got tired of dumping money into it. Finally, I dumped enough money, and bought an auto manual to understand the basics, and I partially restored it to running condition and I love it! It still needs work here and there, you know old switches, AC, etc, but with patience it can be a really nice reliable car. YES, diesels like this smoke a little, but I put a diesel supplement like CETANE in it and the smoke is almost not even noticable. BIODIESEL? If it is DIESEL, it will burn! Oil and gas is what this car runs on.
Listen this car was not meant to be raced OK! The take off is extremely slow, but I found with a high OCTANE supplement and shifting down in a lower gear, the car works like any other (make sure there is enough transmission fluid, not over-filling). The speed and power of this TURBO DIESEL only kicks in when you are driving at around 40-60 mph or so, then you don't even have to hardly touch the pedal at that point. I find this car to be totally unique, just invest some $$$ in it and the 300D is great. (Eventhough, the engine might need to be rebuilt, make sure there are no leaks, I mean diesel engines leak a little but all seals should be replaced.)I am not sure about the conversion factor for vegetable oil, but if they sell it at the pump, you can burn it.


Curtis, Sounds reassuring


Sounds reassuring that you had a good time with your 300D. I wanted to know if you ever had problems starting up the engine. The car has been sitting around a bit and I tried starting it and it won't do anything. I am going to check out the glow plugs and the battery. Have you ever have a similar problem? Im going to try to troubleshoot this problem. Also, how much does an engine rebuild cost? thanks,


Why would you just say stuff like this?

It is completely UNTRUE that it runs on Oil and GAS...The diesel engine will be destroyed if you pump GAS into it. Don't do that!!

If they sell it at the pump you can burn it is an absolute WRONG statement.

Now, that said, it's probbably the best and easiest tpo convert to veg-oil, and will run on Bio_D with NO can also blend and make diesel/VegOil mixes of about 50-50 and run on that (make sure you clean up and dry out the VegOil (ie. Filter and de-water it...MANY suggestions and how-tos right her on this forum and many others.

My first and best advice is find some good forums for VegOil/Biodiesel and read read read....then find some good forums on Mercedes TDs and READ READ READ some more....the injector pump can be tweaked and many other little tweaks can be done to make that Diesel run like a mad hatter.



Chris -- If you still pay

Chris -- If you still pay attention to this post 2 years later (haha), smoke is not good! Diesels should not smoke (very much). You know something is very wrong when it belches dark smoke all over the place! I hope you got that fixed by now.

It is also a slow starter, but once you get on the highway it is a nice little cruiser. I have an '82 300D with 185K miles. Dumped a lot of money into it (rebuilt turbo, etc. -- bought the car for $3K and probably put $3K into it, oh well) and the AC seems to go out every summer. The vacuum is also going out in the engine so it takes a while to turn off even after I take the key out. You should let it idle a little when you park anyway. The vacuum is also very slow on the locks if you don't drive everyday and I even had that vacuum system fixed.

I want to fix up mine to do biodiesel, and this is the first place I came to.

You should really only get diesel fuel at the pump -- NOT GAS! Gas is more refined and the car was never meant to run it! Also beware of idiot oil changer employees. Your car does not need synthetic oil and it may damage it if you switch between them (synthetic wasn't even made in '82!).

And just because the speedometer only goes to 80 MPH does not mean this is the limit! It is so easy to speed in this car ... I have gotten a ticket and I was clocked going 93 MPH. The car could probably go faster, I think (although this is not good for the safety of others and your tires ... and fuel economy). I think the low number is due to freeway speed limits at the time it was made.

Also beware -- if your tape deck goes out and you want to install a newer OEM unit, it's not easy! I finally had to take it to a shop and I had to wait for a guy who had done it before because the other employees had no clue about it.

mbz conversion

I'd love to run a mbz on biodiesel but I'm not a fixit kind of guy; i don't want to read a bunch of manuals . . . sorry . . .I'm planning on moving to the bay area (CA); is there someone there who could help?

poor preacher man

MB300D power problems

I recently read that the fuel filters on diesel -- and especially waste vegetable oil biodiesel -- tend to clog up; diesel type fuels being much thicker that gasoline.

This poster suggested that you learn how to replace your own filters, and carry spare filters with you always. This might help you get more power out of it. These models weren't particularly powerful anyways. I mean the speedometer only goes up to 80mph!


Green beanie

benz 300

unless you get a big engine, diesels are dogs. that said, high gas prices will soon be putting an end to jack rabbit starts. you have to decide what you are comfortable with. Poor maintenance will kill any car, but a benz diesel is built to last if properly maintained.


Where do I begin?
I read alot about BIODIESEL. Seems like lots of work.
WVO seems so much easier.
all I have to do is let wvo stand filter really well of the top and get an in line heated filter and done.
Is this true?
Can I get help?
What is the least costly?
I can buy a electic pump 12volt with an inline filter and screen. I have two 55 gallon drums. I have the smarts.
I also have an electric water heater. New one.
What would everyone do?

hi i have a 300D diesel benz

hi i have a 300D diesel benz two door and like to install a turbo i have another 300D turbo diesel extra car and was wondering if i can install the turbo on the two if it is possible what all do i have to do

I have a 1995 E300D. We use

I have a 1995 E300D. We use pure (B99) in the summer (Texas) and B20 in winter (temp typically in 30-40's. Car runs great.

Here is a shot of the rear deck: I got the lettering at Mercedes Benz of Austin.

The only issue is that I have to replace fuel filters regularly: Bio eats up rubber, and while the lines themselves are the new plastic style, the gasket on the OEM fuel filter is...rubber.

The smoke is due to the fact

The smoke is due to the fact that you system is dirty. Your car has a Mercedes OM617 engine. The OM stands for . You need to do a diesel purge. What are the blow-by test results? Blow-by is where the piston rings no longer seal properly, and some of the exhaust goes into your engine compartment. You can check for this by opening the oil fill cap and starting the engine. If you see exhaust smoke coming-out, then you need to run a compression test.

I have received more information at than anywhere else. The site is great.

there is an adjustment on the

there is an adjustment on the fuel pump, located towards the back on the pump its called an android. it's a 10mm nut,(there may be a cap that you have to take off) loosen the nut and unscrew center screw counter clock wise very slowly. using the throttle linkage rev engine you will hear and feel an increase in power then retighten 10mm nut. this will increase fuel flow and gain more power, note fuel eco will decrease... but now you will be able to take off from a stop alot quicker..note diesel engine are more efficient at operating temp

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