flush fuel tank in car? - PeachParts Mercedes-Benz Forum

odie · #1 01-07-2005, 11:36 AM

Can you flush & clean the fuel tank while it's still in the car? I've been having an algae or fungus problem and just had a lot of water & coolant mixed into the fuel as well.

I'd rather avoid the hassle of pulling the tank. Especially since I will have to remove the trailer hitch too, which is hassle too.

I removed both fuel lines and pulled the tank strainer.

I then flushed the tank with about 2-3 gallons of RUG into the filler neck and out into a bucket under the strainer hole. Which I hope removed99.9% of the water.

Then I capped the two fuel lines and installed the strainer.

Filled the tank with RUG and BioBor and will let it sit a couple days. Which I hope will kill any fungus or algae that may be in the tank.

I plan to drain the tank a couple days later and flush some more RUG through it to rise out any dead algae & fungus. Then put it all back together.

Will a full tank of RUG wipe out any fungus & algae?

boneheaddoctor · #2 01-07-2005, 11:45 AM

Quote:

Originally Posted by odie

Can you flush & clean the fuel tank while it's still in the car? I've been having an algae or fungus problem and just had a lot of water & coolant mixed into the fuel as well.

I'd rather avoid the hassle of pulling the tank. Especially since I will have to remove the trailer hitch too, which is hassle too.

I removed both fuel lines and pulled the tank strainer.

I then flushed the tank with about 2-3 gallons of RUG into the filler neck and out into a bucket under the strainer hole. Which I hope removed99.9% of the water.

Then I capped the two fuel lines and installed the strainer.

Filled the tank with RUG and BioBor and will let it sit a couple days. Which I hope will kill any fungus or algae that may be in the tank.

I plan to drain the tank a couple days later and flush some more RUG through it to rise out any dead algae & fungus. Then put it all back together.

Will a full tank of RUG wipe out any fungus & algae?

Don't think the RUG will on its own.....But Biobor will do it......I would go at at least twice what is shock concentrations....maybe 4 times since you are leaving it there ony a few days.

Did you put a few cans of dri-gas in with the RUG to absorb moisture?

leathermang · #3 01-07-2005, 12:34 PM

Are YOUR TD's Wagons ? Some people use TD meaning other things...
If yours are wagons I don't know if you can effectively flush them in situ.
However, If you have a sedan I suggest that power flushing is completely acceptable way to really clean them out. I took my 240 tank out... but would not do that again because the large holes in the tank and the upright placement makes power washing and evacuation very straightforward....and easier than dealing with the very tight rubber interference gasket at the bottom.
If the only thing you are trying to do is kill algae.. you can do that in the tank with Biobar ... I did this ... and use a clear 90 degree filter up front.. and it only took one treatment per 6-9 months to keep me clear.

odie · #4 01-07-2005, 02:42 PM

the TD is a wagon.

I figure the RUG is not as nice to fungi & algae as diesel might be.

Plus I think RUG might be a lot harsher on whatever might be stuck to the walls of the tank and break it down better.

I added about 1oz BioBor, supposedly "shock" concentration for 40 gallons, the tank is only 18ish gallons I think.

Diesel always felt "greasy" to me and seems to hold water better. The RUG will probably rinse & flush out the tank better.

When I'm done I'll settle the water and crap out of the RUG and burn it in the lawn mower or other vehicles.

But it's all just one big continuous experiment.

boneheaddoctor · #5 01-07-2005, 02:47 PM

Gassolene won't absorb water.....thats why I asked if you put some dri-gas into it....to soak up the water.

leathermang · #6 01-07-2005, 03:06 PM

Alcohol is used in gas cars to combine with the water, and then evaporate... I don't know if it will work with diesel..

boneheaddoctor · #7 01-07-2005, 03:07 PM

Quote:

Originally Posted by leathermang

Alcohol is used in gas cars to combine with the water, and then evaporate... I don't know if it will work with diesel..

He was using RUG.....Regular Unleaded Gasolene...............

not a great idea with diesel as I understand.....the dri-gas (alcohol) I mean

Eric Eliel · #8 01-07-2005, 04:15 PM

I was wondering what RUG was and just about to post this question:

Berber or shag?

odie · #9 01-07-2005, 04:27 PM

well I intend to fully drain all the RUG before hooking up the fuel lines again.

I will definitely have to get some of that anti water stuff and add to the RUG while it's in the tank. I have a little fuel pump I can hook up to it and circulate the RUG in the tank. That should mix the stuff real good and absorb any water that is left.

What's the best stuff to use? A lot of the fuel "treatments" are nothing more than mineral spirits, nathpa, tolene, etc. All which can be bought at Home Depot for a few buck a gallon, not the little 12oz bottle Autozone wants to sell you.

boneheaddoctor · #10 01-07-2005, 04:32 PM

Quote:

Originally Posted by odie

well I intend to fully drain all the RUG before hooking up the fuel lines again.

I will definitely have to get some of that anti water stuff and add to the RUG while it's in the tank. I have a little fuel pump I can hook up to it and circulate the RUG in the tank. That should mix the stuff real good and absorb any water that is left.

What's the best stuff to use? A lot of the fuel "treatments" are nothing more than mineral spirits, nathpa, tolene, etc. All which can be bought at Home Depot for a few buck a gallon, not the little 12oz bottle Autozone wants to sell you.

Dri-gas is just alcohol.......preferibly with as little water as possible.

phidauex · #11 01-07-2005, 05:54 PM

Denatured alcohol from the hardware store will work fine. It is very hydroscopic, so it will absorb moisture (which is also why you want to keep that stuff tightly capped). A gallon should cost you 7-9$, and will last quite a while. Good stuff to have around. In anything newer than a 617 you do NOT want any alcohol getting into the fuel, since the moisture will turn into steam inside the newer IPs (which are somehow different from the older ones, in a way I don't fully understand), and cause all sorts of havok.

But for flushing the tank on a 617, you should be just fine.

peace,
sam

odie · #12 01-10-2005, 11:04 AM

Finnished flushing.

I filled tank with gas and HEET drier Friday. Drained it Sunday.

Flushed a few gallons back though the tank and into a bucket under the drain hole. About a quart of water and algae came out.

I poured off the top, the water & junk stayed in the bottom of the bucket. Kept flushing through about 20-30 times. I got lots of water out of the tank. evne after I total drained the tank before starting the whole process.

The water seperated from gas pretty good so it was easy to run it through again and again.

put it all back together and filled with diesel, BioBor and Diesel Clean. It runs OK but idles a little rough. I guess it will take a little time for the last bit's of water to get purged out of the entire system. The diesel clean is supposed to help remove the water. I guess it just absorbes any moisture and lets the engine burn it.

autozen · #13 01-10-2005, 11:26 AM

I'm still trying to figure out how you got engine coolant in your fuel tank.

It sounds like you are going overboard on the cleaning process. You've done enough. I'd just put fuel and a little biobor in and as someone suggested, use the clear filters so you can keep an eye on things. I don't understand why they even make the opaque ones. If you get fungus again at a later date, kill it with biobor and change the filters. Also if you don't drive the car much, keep the tank topped off. What happens and particularly in humid climates is moist air condenses as the tank cools from the warmer day. What happens on the inside of your big old windshield is what happens in your tank.

Peter

odie · #14 01-10-2005, 12:33 PM

OOPS...I guess I didn't explain the water part...

I had a HIH set up for heating my WVO blend. But I used regular Polyethelene hose and it melted. Thats how water & coolant got into the fuel system.

I've been experimenting with PEX but that gets soft at high radiator temps too so I think I will use copper for my next HIH fuel line.

autozen · #15 01-10-2005, 12:38 PM

You might just try switching to a veggie therm.

Peter