Old fuel a problem? - PeachParts Mercedes-Benz Forum

quacker · #1 02-24-2009, 12:26 PM

Greetings! I'm now the proud owner of a 1983 300SD TurboDiesel (got it for Valentine's Day from my Honey

) and just experienced something that I would like to avoid in the future. Last night my baby (the car - not my Honey) sputtered and eventually stopped. I got a gas can and put 5 gallons in her and she gradually came out of her coma and seemed to recover well. I was down to a 1/4 of a tank (based on the gauge but I don't know how accurate it is yet) when she sputtered to a stop. The fuel was what was in the tank at purchase so I'm thinking the fuel was just old (the car had not been being driven often) and needed to be freshened up. The tank was allegedly at 3/4 when we got it.

Does anyone know if this will continue whenever I get down to a 1/4 of a tank or will it go away as I refill with fresher fuel? Or is it possible that I'm running into some other problem related to fuel delivery?

milner351 · #2 02-24-2009, 12:35 PM

old fuel is much less of a problem in a diesel compared to gasoline engine...

I would check your fuel filters and change them if they look to be old or neglected.

It's possible your fuel gauge is not reading correctly - I would drive it until it gets near the 1/4 mark again - and fill it up - record how many gallons it took to fill it up - compare to the capacity of the tank - and you'll know if your gauge is reading properly or not.

It may also be possible that there is something wrong with the pick up inside the tank.

lowriderdog37 · #3 02-24-2009, 06:33 PM

Depending on how long it's been sitting, it could have water (somehow) in there, or even fungus. I would just drive it, and if you have any more problems, drain the tank/lines, replace the rubber lines while you are at it, filters, tank strainer and start with a nice fresh fuel system.

I would suggest do it all or nothing. As far as I'm concerned, if the car is running well, there is no problem to fix.

barry123400 · #4 02-24-2009, 07:13 PM

I might take the time to verify that the fuel supply and return lines have not been reversed.

t walgamuth · #5 02-24-2009, 07:57 PM

First thing to do is verify that you actually had a quarter of a tank of fuel in it. The only way to do this is to fill it up. I am saying your tank might have been empty and showing a quarter of a tank.

Second I would put some biocide in it if there is any hint of bacteria in the filters....black dots.

oldiesel · #6 02-24-2009, 09:38 PM

Once you determine that it really had a 1/4 tank as suggested by TW i would be suspicious of the in tank screen.On my car when i got it it was doing the same thing and i found the tank screen to be 3/4 plugged up with black crud so only the upper part of the screen was letting fuel thru,once the fuel got below that level it would sputter and eventually die.
Good luck Don

el sea · #7 02-24-2009, 09:42 PM

Quacker,

A fuel tank can be a difficult thing. The diesel fuel WILL go bad, it WILL collect water from condensation and bad fuel sources. Diesel fuel tanks WILL create a build up of crud that WILL give you fause readings on your gauge. Diesel WILL leave a coating of crud over the internal screen inside the tank.

Search for tank cleaning and screen cleaning. Learn to treat your fuel and avoid the pitfalls and enjoy the ride.

El Sea / LC

t walgamuth · #8 02-25-2009, 06:20 AM

Will is a very strong word. I would use the word can.

If you have questions about the fuel take a sample. If its clear, its not infected with bacteria. If in doubt use biocide on it.

I use biocide from time to time but have never pulled a strainer yet.

el sea · #9 02-25-2009, 07:51 PM

If you do pull a sample,pull from the bottom of the tank. This is where the contaminates rest. When I pull a sample for testing I use a product call Liqui-Cult, available on the net.

I clean tanks everyday, mostly boats, emergency generators, construction & farm equipment and with todays fuel (both gas & diesel) WILL go bad. The first thing I test for is water, obtain Kolor Kut water finding paste for this. If water is found it is pumped off, then I start the cleaning process. A tank with clean fuel can have a collection of contaminates that will foul most filters and injectors.

Feel free to contact me PM if you need addition info.

Good Luck,

El Sea / LC

t walgamuth · #10 02-25-2009, 09:24 PM

It sounds like you have a lot of experience with marine diesels.

I agree to pull off the bottom of the tank. I do this by putting a section of copper tube in the end of a plastic tube so it sinks to the bottom.

After pulling all the water out that the hose will pick up I would put in a few cans of antifreeze for diesels and put in five gallons of fresh diesel and head for the nearest station and fill up. Then I would keep an eye on the filter and othewise not worry if the engine ran fine at that point.

I am not sure all your marine experience translates directly to automotive situations.

el sea · #11 02-26-2009, 08:27 PM

Actually most of the marine crafts we service have issues with ethanol. Ethanol is my friend, it will mess up the average fuel system in no time. For diesel most of our customer are stationary types, construction equipment that rest for long periods between usuage and emergency generators. Then there are the emergency issues that come up, two days a go I had to empty a diesel fuel tank on a small Webber Cove trawler and re-plumb the fuel pick-up that had developed a leak. While I am removing the fuel, I am filtering it and removing any water that is present. Store the fuel in barrels until re-plumb is finished, then pump the fuel back into the tank, again filtering the fuel.

What I have found myself doing is introducing my customers to 'Predictive Maintenance'. The fuels that were marketed a few years ago no longer exist. As an additive I use Sentry Diesel, from controlled testing it has proved to address the water issues therefore minimizing those contaminates that cause the crud.

Fuel Tank Cleaning