1980 300TD just switched to WVO- runs rough
 

I just started putting wvo in my 300td. I bought the STC-100 system from mercedes source, but haven't installed it yet. I had the bright of idea of not wanting to wait so I ran my tank dry and filled up with wvo. I started her up and she ran perfectly fine. I took her out for a spin and there is a noticeable power decrease. The car wouldn't go over 50 mph and now barely accelerates at all. I was wondering why it would be like this. I ran it on pure veggie oil one day and it purred like a kitten. Will the STC100 system cure this? All it seems the kit is is a lot of new hoses and a heater element in the engine compartment. It was 100* out today so I assume it doesn't have to do with heating the oil. I know someone will ask so I'll save the suspense you the suspense. The only way I filtered the oil is through a sheet. I read on several forums that clothing works just as well as micron filters etc. I'm going for the absolute cheapest and convenient way to do this. Let me know if you have any ideas. Thanks.

First and foremost, a sheet is not good enough for a filter. Your fuel needs to be filter to 5 micron at least. The primary filter on the car is 5 micron, so it has to be filtered to at least that.

WVO is thicker than diesel, so you need to reduce the viscosity. You can do that through heat (by installing a proper heating system) or through blending...most commonly with gasoline. 10% gasoline with 90% WVO is enough, and you don't want much higher percentage of gasoline.

I'd say both primary and secondary filters need to be changed, and you may need to drain the fuel tank and re-filter the fuel at the very least.

I agree that you need to both filter and dewater your oil way better. There are many ways to to this, some cheaper than others, but sheets and denim are not the final answer. Google cold upflow filtering. I also agree that you need new fuel filters in your car.
A single tank conversion is not the best way to go. In my opinion the only long term way to burn straight veggie oil is in a heated, two-tank system.
Check out the Greasecar site, they have a lot of good info there.

Cheap WVO systems usually mean dead cars. And as stated before a sheet is not enough filtering, and even at 100degrees your VO is still thicker than diesel and won't burn completely. Change both your fuel filters and mix in some diesel, and see what happens.

The biggest problem with single tank conversions is the cold starting. Most single tank conversions don't heat the oil enough or at all before starting the car. So you're running cold thing oil through the system for a while until you get everything up to temp. Cold oil caused all kinds of issues, clogged filters, plugged injection pumps and injectors, and stuck piston rings. I ran my 240D on WVO in a two tank system for over 60k miles and had no problems at all. I would strongly discourge you from running a single tank system. They don't work for long and will end up costing you more money than you're saving.

OK. Thanks for the input. When I finally install the STC100 system (heater included) that should take care of the problem. It bypasses all of the stock filters and they provided me with one thats tripple the size for the primary and then there's a secondary filter too. I'll pump out the oil I put in the tank and find a better way to filter it. I was going for the easiest way to do it which didn't work. Thanks again.

I wouldn't completely bypass the stock filters...You should probably plumb it up to go through their filters, then the stock filters, then the injection pump.

FYI-on a single tank system you're running on borrowed time. Unless your tank and lines magically reaches 180°F on it's own prior to starting the car.

That is taken care of in this system. All you do is let the glow plug warm up the oil in the pre-chamber (different than the stock ones) and it then heats the WVO to the temp set on the thermostat (included). Pretty awesome set-up from mercedescourse and great instructions.

If someone can assist me here I have a questions about the fuel lines. The line that comes from the top of the stock fuel filter...is that the return line that goes to the fuel tank to return the excess fuel??

Two lines run from the fuel tank to the engine compartment, side by side at the firewall/fenderwall. The supply goes to the primary filter (small plastic clear/semi-clear inline filter), so the other one is the return.

Here's a link for the OM617 dual tank fuel routing. Mercedes WVO Conversion There are also pics and parts lists.


Jason
WVO Designs

I'm one of the thick headed people that has to have something not work before he believes what everyone else tells him. The car won't start now, prob because I can't get the wvo hot enough. I don't want to have to put in a complete separate tank. What about a small 2 liter tank under the hood to start the car on diesel and then switch over to WVO and then again to switch back over to diesel before shutting the car off? I think that would help the whole thing out a little more??

add heaters from fattywagons .com that will help you,just heat and go.

If your car won't start, it's not because the oil is to thick,, at this point, you have other issues. I would suspect lack of fuel due to a clogged filter. But could be something totally different. How long since the valves have been adjusted? Are all your glow plugs operating?
It's hard enough to start a Mercedes on 80-90% WVO (10-20% diesel) first time every morning. It's near impossible to start if a few glow plugs are burned out.

I burnt wvo for 30,000 miles.Good emergency fuel,good for summer.A pain during cold months.I went back to diesel for now two years.I love diesel,power,fast starting,no mess.However if war breaks out I will run my 300 gals. saved

storing wvo
 

How long can you store WVO?
Does it ever go bad as a fuel?

Jeff