Diesel Fueling

I was curious if you ol' boys are more precocious about filling your tanks when it is raining or snowing than normal. Like getting moisture in the fuel tank.

[Matt L]

If there's a cover to keep rain out, you're fine.

Adding fuel displaces the air rather than drawing any in. You should be more worried about driving in the rain or snow.

[bullwinkle]

I'd try to avoid getting rain in, but I try to keep my tanks full (esp. in rainy or very humid weather)-stops condesation in the tank=no water in the fuel.

Will those fuel filters help trap water to keep it from getting into the engine??

[tangofox007]

Originally Posted by Rebe

I was curious if you ol' boys are more precocious ....

It's tough to be "precocious" when you're an "ol'boy."

[oldnavy]

Originally Posted by Rebe

Will those fuel filters help trap water to keep it from getting into the engine??

I believe the OEM filter does not stop water and if you have water worries then you need to install a small water seperator as I will be doing in the near future. US fuel is fairly clean normally, but we do seem to have problems with water.

[t walgamuth]

i put in some deicer from time to time and fill when i need to. most fueling spots are covered. a few drops here and there are not a concern to me.

tom w

[toomany MBZ]

I installed a water seperator on the CD, don't drive it much. As bullwinkle mentioned, condensation will happen more when it's humid, I think, yet is an ongoing condition. Keeping fuel topped off is your best bet. I know for gassers you can add some isopropyl alcohol to absorb water, then it'll burn off with fuel. You would need the 90+% stuff. What you get at the local drug store, around 70%, has absorbed all the water it's going to.

[oldnavy]

Originally Posted by toomany MBZ

I installed a water seperator on the CD, don't drive it much. As bullwinkle mentioned, condensation will happen more when it's humid, I think, yet is an ongoing condition. Keeping fuel topped off is your best bet. I know for gassers you can add some isopropyl alcohol to absorb water, then it'll burn off with fuel. You would need the 90+% stuff. What you get at the local drug store, around 70%, has absorbed all the water it's going to.

Generally all your condensation will be from moisture drawn into your own tank, but it also happens a lot in the storage tanks at stations. Never add alcohol to diesel because it is always either mostly water or will draw water. If you live in and only drive around in the desert SW of the country you won't have much to worry about, but around here where I live, SC, NC GA, FL, OR and WA you be risking problems w/o a fuel/water seperator. Refilling when below 1/2 tank will help some, but not enough to keep 100% the condensation water out of the fuel system.

The reason I asked is because I have always been told water and diesel are two volatile components inside a diesel. I have seen MB service tecnicians talking about motors on the bench with bent & twisted rods from water related issues.

[oldnavy]

Originally Posted by Rebe

The reason I asked is because I have always been told water and diesel are two volatile components inside a diesel. I have seen MB service tecnicians talking about motors on the bench with bent & twisted rods from water related issues.

That is from large volume sucked into intake and called "hydrolock" liquid does not compress well and will raise hell with an engine. It can also happen by over filling the crank case with oil, it is rare, but I have seen it done to a VW TDI about 6 years ago. I saw a Dodge Cummins in the shop last year with a hydrolocked engine, lots of engine parts are still in the river he was fording. Then only thing salvaged from the engine was starter and IP, head, block and pan were AFU with holes.

[F18]

It always seemed odd to me that Mercedes did not incorporate a water seperator into the fuel filter system... My 94 K1500 Turbo Diesel Blazer did have a water seperator and water sensor and water alarm/indicator on the instrument panel. The way the filter system was set up I could back flush water out that had been been seperated by the filter by just opening a turn valve in the delivery line to the filter while the car was running. It was messy but you were suppose to do the procedure before changing out the filter element. The filter housing also had an air bleed valve to assist in bleeding the fuel system.......wish Mercedes had that!

[Hatterasguy]

I try not to fill my tank when its raining unless I have to because I get wet. I used to fill it before it snowed a lot, but the car doesn't go either way so I just gave up.

The spin on is a water seperator, if anything gets in there it will be filtered out.

[rudolfgreen]

stanadyne fm100, 5micron w 150micron prescreen, w bowl option

[BioPOWER]

You can buy filters with built-in water seperators that fit MB diesels, however IIRC they won't fit the shorter housing of OM60x engines.

My Jetta's filter has a built in water seperator with a drain on the bottom, and my Powerstroke has a valve that can be opened to drain seperated water.