Bio-Diesel / W115 Questions

[SoCalBomb]

Okay here's the deal . . .

Currently I own a '95 Civic, it's a great car, but it just doesn't do it for me. So i found a buyer for my Civic, and therefor I have the freedom to look around for a replacement car.

Being a self-proclaimed "automotive-activist" & and interested in alternate fuels/energy sources, i've become very interested in having a Bio-Diesel Mercedes Benz.

I found a W115 '75 300D around me, with a recently re-built motor, and AC (which is a must in Southern California). I've had a '79 300CD in the past, so i'm use to some of the "quirks" of having a diesel. On a side note . . . i've thought about getting a W123 300D, but would prefer the nostalgia of the W115.

My Questions....


What should I look out for on this Mercedes Benz model? besides the usual of rust etc.

What's your opinion of the car?

How would I go about converting the car into a Bio-diesel car?

*I've done some research and have found mixed answers. Some sources claim no changes are needed, some say adding more fuel filters is required etc.


What else should I be concerned about?


Any comment would be highly appriciated.

(RE-POSTED in Diesel Discussion)

[joshhol]

I can't say anything about the conversion, other than if you do a search you will find plenty, I imagine.

About the car itself. It is without a doubt one of the finest to be built by Mercedes -Benz. My 300D (115) just passed 400,000 miles on Saturday and I still love the car. I will never sell it.

Trick is to get a nice color, they had some funky ones in the day.
Mines white/blue, very pleasing.

So, make sure the engine was rebuilt well. If you're serious about the car, get a compression check. Once you do that, if you get it, adjust the valves, change all the fluids and filters and then drive it.

Warning: It will be slow in SoCal traffic, but they jump out faster than 123's off the line, until turbo's kick in that is. They handle much better and you feel more in touch with the road in it. They're also built better IMO as things on my brother's car are screwed up that never have on mine.

I had mine in L.A for a while and it was fine, you just need to be less daring.

Note: Stay away from an AT 240D unless you have a prescription for medical marijuanna. Then you won't care how slow it is.

[SoCalBomb]

Wow, those were some very kind words about the W115.

And no, I wouldn't buy a 240D, that's just unthinkable.


Thanks for your reflection, and I'm glad your 300D has been so good to you.

[redghost]

I have been running my 220D with no issue on Bio. Most I have had to deal with is getting the slime the dino left behind out. A few filters later all is better. Runs QUIET and smooth. No loss of power at all, actually runs better. Got her up to 80mph, where the dino got me to 70 at best, downhill, with a severe tailwind.

[coldwar]

Just over a month ago I got a '76 300D from eBay. It's difficult for me to compare with other models, as this is my first MB. My only other experience was trying out a W123 240D automatic many years ago.

This car is truly awesome- some say these were best years for MB quality and I believe it. I bought it site unseen for $3500- quite risky indeed, but when I took it in for Inspection and licensing, it passed with flying colours- absolutely nothing was wrong, and absolutely everything works, except a minor vacuum issue with the door locks- par for the course with any older Mercedes.

The engine is very strong with 140,000 actual miles. On a very steep highway incline, which typically will slow a tractor-trailer down to 45 MPH, mine drops from 65 to 60 MPH. On this same incline, my wife's Cavalier does an automatic downshift to maintain 65 MPH. Also, off the line, I find the car very responsive, especially as it's normal mode is to start off in 2nd gear! To get the true 1st gear with this 4 speed automatic, you have to take the stick down to "L" which I recommend if you're starting off on a hill, or want to beat the snot off some little Ricer at a stop light. My fuel milage is consistantly 25 MPG. I think it could do better- I have done nothing yet to investigate the valve adjustment, timing, condition of injectors, etc. I find the car starts hard when hot- so there is definately something not quite right, but runs flawlessly once started. Cold starts with glow plugs are always bang-on, although the glow light stays on for almost 40 seconds, which seems like an eternity.

Body wise, mine was never driven in winter in it's entire 28 years. There was still some rust, most of which I have already taken care of myself- a little bit around the rear wheel arches and under the trim strip on front fender. Also had a pretty big hole at very front of the sill on one side- again I fixed this easily. Only rust I have left is at very bottom of rear quarter panel next to the muffler. I think it's bad enough that I need to cut it away completely under the rear bumper side guard and weld new metal in. From reading, I am aware that these cars generally have far more serious rusting than mine does, so be aware. Other body features- all door and window rubbers on mine are still in excellent shape- I get no wind noise, and even in the heaviest of rain or through a car wash, not a drop finds its way into the car. Would there be any other 28 year old cars like that? There is a lot of chrome on the car by modern standards, and mine is absolutely flawless- no pitting anywhere, which says a lot about how they built everything "overkill" back then.

The car is very "old school" which is what makes it so endearing. The trouble prone MB vacuum system is much simpler on a 115- the heater controls are still cable operated for example, and there is no vacuum control associated with the tranny, or EGR (in fact I don't think it has EGR at all). The old OM117 engine, although only 77HP is probably the most reliable ever- cast iron head doesn't crack like the more modern units. Every mechanical component is overbuilt- the starter is so big it would look at home on a Kenworth- same with everything else under the hood.

I plan on doing a WVO conversion next spring when I take the car out of storage. I live in the cold north, so even in spring and fall, it means I need to use the two tank method- only in July and August would I be able to put veggy direct into the main tank. I don't think I'll go the conversion kit route with all the expensive components. Like for example, why not just have a $50.00 picnic cooler in the trunk for the WVO tank? The rest is plumbing and fittings- except for the specialized changeover valve. There are seemingly hundreds of different ways to go WVO- spend a lot of time reading and doing your final design strategy.

Bottom line- look out for the rust- other than that, you can't go wrong with the W115 300D.

Dave

[kpb]

As I recall I saw an ad recently in the "Cars for sale" part of this board which was a bio-diesel conversion with a link to an interesting site as well. Very informative as this is all new to me. Good luck.