How to drain tank? - PeachParts Mercedes-Benz Forum

paddo · #1 12-18-2010, 07:26 PM

This probably seems like a dumb q, but how do you drain the fuel tank? Is there a drain plug and any special instructions to get it off?

kerry · #2 12-18-2010, 07:42 PM

Emptying the fuel tank

Emptying the fuel tank

paddo · #3 12-18-2010, 08:13 PM

That looks like a good way to drain it, but I'm trying to get water out of the bottom of the tank so is there a plug in the tank? Sounds like not. If the fuel line sucks very close to the bottom of the tank that should be almost as good. Doing that after car has sat overnight should get the max water I'd say. then I'll see how much water I get then add something to disperse the remaining water into the fuel, probably that startron stuff.

Biodiesel300TD · #4 12-18-2010, 08:14 PM

The fuel supply does pickup from the bottom of the tank.

paddo · #5 12-18-2010, 08:33 PM

I got an idea, I'll just throw some water dispersant in and hope for the best.

babymog · #6 12-18-2010, 08:38 PM

Water dispersed in fuel is still bad. It might run, but it is not good for the injection pump, best to remove as much water as possible before the dispersant (which is likely just alcohol).

I believe that your primary (the metal cartrige) filter also has some water-trapping capacity, change the filter after you run out the bad fuel.

paddo · #7 12-24-2010, 03:02 PM

Quote:

Originally Posted by babymog

Water dispersed in fuel is still bad. It might run, but it is not good for the injection pump, best to remove as much water as possible before the dispersant (which is likely just alcohol).

I believe that your primary (the metal cartrige) filter also has some water-trapping capacity, change the filter after you run out the bad fuel.

do you know what the water does to the IP? I believe it can corrode the lift pump, esp the valve springs so that might be the case with the IP chambers as well. I wonder if it is still harmful when it is fully dispersed/dissolved in the diesel? I should at least try to syphon some out of the fuel outlet, even if only to see what it looks like.
Since adding about 10% gasoline to the tank, the new in-line filter has not clogged so that might turn out to be a successful treatment to kill the organisms, bit early to tell yet though. I still think the main problem is presence of the water and not presence of the growth, so I'll add some of the tank cleaner after seeing how the new filter holds out for a bit longer.

compress ignite · #8 12-24-2010, 03:57 PM

1. Other than from badly maintained fuel sources...How the Heck did water get
in your tank?
2. Almost ANY water dispersant is basically Alcohol. No. No. for Diesels.
3. Major Water Infestation...I'd DRAIN the Tank completely,Remove the Fuel
Strainer and clean the tank.

paddo · #9 12-24-2010, 06:06 PM

Quote:

Originally Posted by compress ignite

1. Other than from badly maintained fuel sources...How the Heck did water get
in your tank?
2. Almost ANY water dispersant is basically Alcohol. No. No. for Diesels.
3. Major Water Infestation...I'd DRAIN the Tank completely,Remove the Fuel
Strainer and clean the tank.

So do you disagree with the general consensus here that starbrite startron enzyme tank cleaner is the best treatment? So strong is the opinion on that, that a couple of people here got very belligerent and insulting towards me when I didn't immediately swallow this wisdom whole. That's the price you sometimes have to pay for using scientific rigor.

I've already paid $40 for it (if it's alcohol I should have got cognac) but haven't added any yet. Certainly there are a few positive and believable testimonials for the stuff so it sounds safe. What is the problem with alcohol?

As to how water got in the tank, I don't know off-hand - condensation build-up over many years? Fuel strainer does not seem to be obstructed. Maybe someone swapped the lines in the past?

paddo · #10 01-06-2011, 01:53 AM

Well it's been a while now since mixing in some gasoline to my diesel tank. the new inline filter has not blocked and the line seems completely clear of obstruction. so it looks as if this could be a promising treatment for diesel "algae" attacks. One case is not enough to prove much, but it would be good if a completely free treatment was successful at getting rid of this problem. In fact slightly less than free since gas is cheaper.

I still have the $40 container of startron tank cleaner and haven't used any yet, so I could see how the gas treatment went on its own. It would be a bit surprising if it worked perfectly since i think the main thing to do is get the water out of the tank, but so far it seems to have got rid of it.

whunter · #11 01-06-2011, 02:47 AM

Quote:

Originally Posted by paddo

Well it's been a while now since mixing in some gasoline to my diesel tank. the new inline filter has not blocked and the line seems completely clear of obstruction. so it looks as if this could be a promising treatment for diesel "algae" attacks. One case is not enough to prove much, but it would be good if a completely free treatment was successful at getting rid of this problem. In fact slightly less than free since gas is cheaper.

I still have the $40 container of startron tank cleaner and haven't used any yet, so I could see how the gas treatment went on its own. It would be a bit surprising if it worked perfectly since i think the main thing to do is get the water out of the tank, but so far it seems to have got rid of it.

Water in diesel fuel always does damage!

Cavitation
http://www.peachparts.com/shopforum/showthread.php?t=272133

Fuel/Water Separator....I SEARCHED!!
Fuel/Water Separator....I SEARCHED!!

How much Fuel per hour? water filter/seperator
How much Fuel per hour? water filter/separator

FYI:
You should NOT use gasoline in your diesel, MB put out a TSB on this issue = use kerosene.

Gasoline does nothing to algae/fungus.

A small percentage of gasoline:
* May break up diesel sludge.
* Lower the jell point of diesel fuel.
* Lower the diesel fuel combustion/ignition point = easier to start cold.
* Reduce your MPG.
* Reduce the lubricity of ULSD = greater internal wear on the injection pump.

Ethanol-diesel fuel blends, cause cavitation, resulting in injection pump and injector damage.

More FYI data:

MB diesel filtration, how it works.
http://www.peachparts.com/shopforum/diesel-discussion/141211-mb-diesel-filtration-how-works.html#post1055075

fuel filter change
http://www.peachparts.com/shopforum/diesel-discussion/112664-fuel-filter-change-post824006.html

Diesel filters, no tank strainers please.
http://www.peachparts.com/shopforum/diesel-discussion/140349-diesel-filters-no-tank-strainers-please-post1046422.html?posted=1

Primary filter melted by biodiesel?
Primary filter melted by biodiesel?

Algae/Fungus fixation...
Algae/Fungus fixation...

Biobor, what is it, why do I need it???
http://www.peachparts.com/shopforum/diesel-discussion/105304-biobor-what-why-do-i-need.html#post723857

Filters, Fungus, Biocide, etc.
http://www.peachparts.com/shopforum/diesel-discussion/115952-filters-fungus-biocide-etc-post823378.html

Algae Clogged Filter Pic StarTron WORKS !
Algae Clogged Filter Pic StarTron WORKS !

.

paddo · #12 01-15-2011, 10:30 AM

FYI:

Quote:

Originally Posted by whunter

..........................You should NOT use gasoline in your diesel, MB put out a TSB on this issue = use kerosene.

Gasoline does nothing to algae/fungus.

A small percentage of gasoline:
* May break up diesel sludge.
* Lower the jell point of diesel fuel.
* Lower the diesel fuel combustion/ignition point = easier to start cold.
* Reduce your MPG.
* Reduce the lubricity of ULSD = greater internal wear on the injection pump.

Ethanol-diesel fuel blends, cause cavitation, resulting in injection pump and injector damage.

It has been a few more weeks and there is no longer any indication of filter blockage, suggesting the growth has gone from my tank.

The reason Mercedes once recommended to add gasoline in winter if necessary, was for better starting. The reason for changing that recommendation was the risk of explosion. Pure gasoline's partial pressure creates a gas/air mixture that is too high in gasoline to be explosive. A certain range of ratios of gasoline will create an explosive level of gas:air, but I don't know what that ratio range is. It's a good point that a lot of modern gasoline has ethanol and I hadn't heard of ethanol damaging injectors before. I'm not sure if ethanol is added in PA / Jersey.

As far as the tank growth goes, it seems clear that it is not a problem for gasoline fueled vehicles. Clearly the growth can't feed on pure gasoline. The question is what minimum ratio of gas:diesel is required to kill the growth. My recent experience seems to suggest that the amount I added was very effective but I'd like to see a few more experiments with this. OF course if you have information that refutes this, I'd be interested to see hear back.

It does seem that due to the possible ethanol issue, it would be better to avoid adding gas all winter, and is unnecessary anyway. However I don't believe that a tank of 10% gasoline no more than every 2 or 3 years (when there is water accumulation leading to growth) will cause significant reduction of injector life. It may be that kerosene is similarly microcidal although I doubt it since it is much more similar to diesel fuel and a lot more pure. But if it is, that would be the perfect solution. I saw Kero the other day for sale, cheaper than diesel! Next time if ever, I have a grawth problem, I'll try a kerosene treatment. There may be forum members who run kerosene mix here, who can report on whether they have ever had a growth problem.

The other dilemma is whether to add any of the expensive tank cleaner I bought to emulsify the water. A previous poster advised that this emulsified water is just as harmful to the fuel system as unemulsified. Possibly it separates out quickly as it is heated on the way to the injectors, which would be harmful of course. so I'm not sure what to do, I think I'll just keep driving for now since the problem seems to have been solved.

whunter · #13 01-15-2011, 02:27 PM

Quote:

Originally Posted by paddo

FYI:

It has been a few more weeks and there is no longer any indication of filter blockage, suggesting the growth has gone from my tank.

The reason Mercedes once recommended to add gasoline in winter if necessary, was for better starting. The reason for changing that recommendation was the risk of explosion. Pure gasoline's partial pressure creates a gas/air mixture that is too high in gasoline to be explosive. A certain range of ratios of gasoline will create an explosive level of gas:air, but I don't know what that ratio range is. It's a good point that a lot of modern gasoline has ethanol and I hadn't heard of ethanol damaging injectors before. I'm not sure if ethanol is added in PA / Jersey.

As far as the tank growth goes, it seems clear that it is not a problem for gasoline fueled vehicles. Clearly the growth can't feed on pure gasoline. The question is what minimum ratio of gas:diesel is required to kill the growth. My recent experience seems to suggest that the amount I added was very effective but I'd like to see a few more experiments with this. OF course if you have information that refutes this, I'd be interested to see hear back.

It does seem that due to the possible ethanol issue, it would be better to avoid adding gas all winter, and is unnecessary anyway. However I don't believe that a tank of 10% gasoline no more than every 2 or 3 years (when there is water accumulation leading to growth) will cause significant reduction of injector life. It may be that kerosene is similarly microcidal although I doubt it since it is much more similar to diesel fuel and a lot more pure. But if it is, that would be the perfect solution. I saw Kero the other day for sale, cheaper than diesel! Next time if ever, I have a grawth problem, I'll try a kerosene treatment. There may be forum members who run kerosene mix here, who can report on whether they have ever had a growth problem.

The other dilemma is whether to add any of the expensive tank cleaner I bought to emulsify the water. A previous poster advised that this emulsified water is just as harmful to the fuel system as unemulsified. Possibly it separates out quickly as it is heated on the way to the injectors, which would be harmful of course. so I'm not sure what to do, I think I'll just keep driving for now since the problem seems to have been solved.

Diesel owners need to know fuel data
Diesel owners need to know fuel data

scottmcphee · #14 01-15-2011, 05:16 PM

Chuck Norris just opens the filler cap and tips the car over, and catches the fuel in a bucket sitting on the ground. Isn't that how most people drain a tank?

paddo · #15 02-19-2011, 05:26 PM

Been quite a while longer and I've been through a couple of tanks of diesel since the gasoline treatment (about 15% gas in 1/2 to one tank of diesel, in an attempt to kill the infection) and still no sign of slime or blockage.
At this stage it looks like this could be a great and free way to treat tank "algae".
I still haven't broken the seal on the $40 container of tank cleaner that was recommended on this forum. Oh well maybe it will be of some use sometime. I think the small amount of water is probably still in the tank so this could disperse that if necessary down the line.

Hopefully this will be useful to some diesel runners, although I seem to have got the cold shoulder from many of the regulars on this forum for daring to question the prevailing wisdom. Be careful not to put too much gas in though as it could damage the motor, but at 10 to 15% will be fine.