I have a 91 MB 300 DT which I have converted over to run WVO. My issue is that I developed a fuel leak in the fuel heat exchanger (I think), which I believe is unrelated to the conversion to WVO. According to my fuel system diagram there is a heat exchanger in-line just before the lift pump. It appears that there is a leak in the gasket where the fuel enters the switching valve.

I live in NC and don't expect the wether to get too cold. With that in mind, can I just re-route the fuel and eliminate the HE all together? It looks like a real pain to access and replace this item, so I would prefer to just bypass it.


TIA

KEN

You need to replace the heat exchanger. Cold WVO or SVO does not inject or burn properly, resulting in even more problems. Is the exchanger the type with coolant running through or around it? If it is, you could be contaminating your fuel with coolant, or your coolant with fuel, or both. I do not know who made your WVO kit, but I do know that WVO and copper are not a good mix.

Sorry, I did not explain myself clearly. The HE with the leak is one that is a stock part on the car. The HE loop is quite small, so it would not work for the WVO anyway. What is leaking is the switching valve with is attached to the engine block. There are 4 hoses coming off of it. THe fuel-in and fuel out are two of the lines. THe other two lines run to a small HE--I assume that it is similar to the windshield wiper fluid HE. Apparently when the weather gets cold enough, the switch valve swtiches so that the incoming fuel goes through the HE before going to the lift pump.

The HE for the WVO is a large tube-in-tube variety. I have a Frybrid system, so the WVO is heated all the way from the tank to the engine. I have no issues with this system.