water in fuel. WVO plumbing problems - PeachParts Mercedes-Benz Forum

odie · #1 01-05-2005, 10:14 AM

My car died yesterday. Just cruising along and then nothing. no power at all and then it just died.

I check the in line filter and it was pretty milky looking. I removed the main filter and pour it out. It felt really watery. Diesel has a real greasy/slippery feel. This felt almost like used radiator water.

My system...I have a HIH hose-inside-hose fule line. Fuel line is 3/8 "ice maker" type plastic? hose inside 3/4 heater hose. Feeds coolant from the head into the HIH then back to the water pump inlet.

I appears my fuel line either ruptured or developed a leak of some kind. The fuel line is under vacuum and the coolant hose is under pressure. So I believe the coolant forced itself into the hole/rupture of the fuel line.

I disconnected the HIH and reattached the OEM fuel lines. Then bleed the system best I could. After several, several tries, the engine finally started and ran OK.

Half way home the car started to run real hot. Definitely coolant leaking somewhere. I added some water and made it home OK and parked.

An hour or so later the car would not start again. The inline filter still looked milky and the main filter was still watery feeling. I bleed the system again with no luck. I filled a jar with fresh diesel and put the lift pump hose into it and bleed and cranked a lot more. The engine finally started. I left it at that.

when I get home today I'll drain the fuel tank and blow the OEM lines out. I'll leave the tank strainer out and hopefully any moisture will evaporate.

I'm going to remove the HIH system and take it apart to see what happened. I just made the thing this past weekend.

JamesStein · #2 01-05-2005, 10:34 AM

Ice maker tubing? The PVC sort? No way that will stand up to 80 degrees C.

odie · #3 01-05-2005, 10:56 AM

Really? I have the veggie oil book "fryer to fuel tank" i think it is called.

Isn't that the type fuel line they use for the HIH heated fuel line? I was sure that was the type line that he used in his book. I got it at Home Depot, 3/8 ID 1/2 OD, it look pretty sturdy.

What kind of hose is used for the HIH system? The book clearly showed a semi-clear rigid plastic type tubing. Compression fittings were used to seal the ends.

R Leo · #4 01-05-2005, 11:12 AM

This is precisely the reason I prefer to use electric heating. Free water in your fuel will kill an IP pronto.

TwitchKitty · #5 01-05-2005, 11:16 AM

Sorry this had to happen, stuff like this should be fun.

If you are having material failures you may want to spring the bucks for Dana Linscott plans. The time you save scrounging for parts and reinventing the wheel may make up the cost.

When I researched WVO conversions I decided I didn't want to do any of that to my car. Since I currently live in the south I didn't need it anyway. I just run the blend and electric pump back by the tank.

I may add an electric glow plug type heater if I need it.

odie · #6 01-05-2005, 12:07 PM

Well, I hope the IP isn't toast.

I got the car to run again last night using a little jar as a fuel tank. So I hope all, or at least 99% of the water has been purged.

The lines and tank will be completely purged before reconnecting.

Why would some water kill the IP? Pure water would have no lubrication but the engine would qui running long before the loss of lubrication could even begin to cause problems IMHO.

Now, if the water was left in the IP system for a little while, I can see rust and/or algae possibly starting.

R Leo · #7 01-05-2005, 12:35 PM

Quote:

Originally Posted by odie

Why would some water kill the IP? Pure water would have no lubrication but the engine would qui running long before the loss of lubrication could even begin to cause problems IMHO.

You're right...a large amount of water all at once would stop the engine. However, small amounts of free water are the worst. The fit between the IP's plunger and cylinder is an incredibly close tolerance and absolutely must have the lubricating properties of fuel oil in order to prevent scuffing of the cylinder wall. Water isn't all that great a lubricant, especially at 2500+ psi.

Additionally, small amounts of water will cause cavitation in the plunger, pressure/delivery valve assembly and injector nozzles resulting in erosion of the metal in those areas.

Jimmy Joe · #8 01-05-2005, 01:01 PM

Quote:

Originally Posted by odie

I have the veggie oil book "fryer to fuel tank" i think it is called.
The book clearly showed a semi-clear rigid plastic type tubing.

That book is old news. I would be real careful before using its advice for an actual conversion. There are much better tried and tested products and methods out there now.
It is imparitive that the products you use can take the heat and are suited for the chemicals used; any old tubing will most certainly give you trouble in the long run.
Think of "From the Fryer to the Fuel Tank" as a sweet, old-school introduction to veg oil. Like 8 track tapes were an introduction to album rock.

odie · #9 01-05-2005, 02:18 PM

the hose I used was POLYETHELENE if my spelling is right. What is everyone else using?

Is this POLYETHELENE stuff no good for heated WVO and diesel? The coolant is never going to reach exceed 100'C by much. Water will not get hotter than 100'C without changing the pressure. And the radiator cap is only about 15psi. That is only going to raise the boiling point a few degrees more I believe (it's been about 15 years since I last studied physics).

R Leo · #10 01-05-2005, 02:50 PM

Quote:

Originally Posted by odie

And the radiator cap is only about 15psi. That is only going to raise the boiling point a few degrees more

FWIW, the boiling point of a liquid is raised 3° F per 1 PSI of pressure. But, if the coolant is 100°C it's that temp regardless of pressure.

I suspect that poly icemaker tubing simply isn't a good choice for that application. And, I'd be surprised if it melted; it probably cracked or split at a bend, or abraded where it passed over the edge of a structural member in the car.

Jimmy Joe · #11 01-05-2005, 10:33 PM

Quote:

Originally Posted by odie

Is this POLYETHELENE stuff no good for heated WVO and diesel?

This stuff comes in many flavors; i.e. temp range, chemical imperviability, pressure range.
You have to make sure you buy the correct stuff for your application.
I hope you don't have IP troubles; you caught it fast.

coachgeo · #12 01-06-2005, 10:51 AM

I will again reccomend HOH. If you look at the conversion companies products (Greasel etc) I think you will find none of them use HIH anymore either. Especially since you are dealing with a 300D. These buggers love vege and there are known to be ones on the road overseas that run pure oil with no conversion at all.

Use the hose on hose just to help the fuel flow from the tank. Honestly you may not even need that If corpus cristy is a warm TX climate and you dont venture far from it. Do a final heating of the oil to the temp needed for better combustion up in the engine compartment via a home made or commercial coolant/fuel heat exchanger or a 12v one orrr?.

For more information a discussion on this conversion is going on over at Maui Green SVO Forum

Jimmy Joe · #13 01-06-2005, 12:51 PM

Ya, I never liked HIH. Too much opportunity for failure, and failure here is catastrophic. Coachgeo has it right, HOH is the way to go. Combine that with Dana's Hotrod heated fuel pickup, and you will never have coolant troubles again.