fuel pre-filter plugging-HELP? - PeachParts Mercedes-Benz Forum

mdlwolf · #1 01-22-2003, 09:07 PM

Hello,
I'm having a reoccuring problem on my 83' 300d. The fuel pre-filter keeps plugging with small bits of black stuff, almost looks like poppy seeds? When the filter plugs the car looses power, starts to miss and then just stalls and won't start again. The first time it happened I was low on gas, it took 17 gallons to refill the tank, and changing the pre-filter made it fire right up. The next time it happened was about 350 miles later. I changed the pre-filter and it ran fine but died again only ten miles later. I changed the pre-filter again and it started right up so I filled up the tank again, this time it took 15 gallons. I made it to work and parked and when I went to start it up again 8 hours later it wouldn't start, it's been very cold here, between 0-10 degrees. I put jumper cables on it because it was turning over very slowly, and it took over an hour of repeated cranking to get it to start. Once it did it ran fine and I've started it several times tonight since then and it's started fine with the engine warm. However, I looked at the pre-filter again and the screen is covered again with the same black particles, only 38 miles later? I've gotten diesel from different places so I don't think it's the diesel. Any help would be greatly appreciated!

kerry · #2 01-22-2003, 09:34 PM

Sounds to me like you need to clean the fuel tank. Could be algae. I'd use some algaecide after I cleaned it. I know on boat fuel tanks, shops use a small pump with a series of filters to clean the gunk out of the tank. They recirculate the fuel thru the filters so they don't have to pull the tank out of the boat. May be a good option in your case. I have no idea how hard it is to clean the tank in your car.

mdlwolf · #3 01-22-2003, 10:01 PM

Seems like my problem may be that the algea is dying and coming loose? It just started when it got really cold, don't know, but this stuff can't live at these temperatures, can it?

airfoill · #4 01-22-2003, 10:23 PM

mdlwolf:

Lately I have been changing prefilters too on my 240D and I am beginning to think I've got algea. Does this picture below look like your prefilter? Mine haven't clogged up yet but I've been changing the prefilter about twice a month now.

Herb
'82 240D
'87 300SDL
'92 300D 2.5 Turbo

mdlwolf · #5 01-22-2003, 10:46 PM

Well not that bad, but basically yes, except my filter has more black particles than brown, although there are some brown particles. Why hasn't yours plugged up with that much algea? Mine has much less and the car won't run, you can still see the screen in mine. Maybe it's a temperature issue. I'm thinking that at 0 degrees the fuel is more viscous and less willing to flow through a partially plugged filter?

Anyways, how do I approach this?

airfoill · #6 01-22-2003, 10:53 PM

Thanks Bill, I have just ordered some Biobor per your recommendation to see if I can get rid of this stuff. Man, I can't believe that algea can grow in diesel fuel like this. I thought algea needed water....but I guess maybe there is water in the tank.

Herb
'82 240D
'87 300SDL
'92 300D 2.5 Turbo

kerry · #7 01-22-2003, 11:06 PM

If the low temperatures are exacerbating your problem, an in-line fuel heater may help you get by until you can get rid of the algae.

#8 01-22-2003, 11:43 PM

Don't forget about the in-tank filter.If you fuel gauge seems a bit
off lately,you need to take this apart and clean it also.This stuff is
just the slime that ate Toledo and you need tostop it NOW,or it will stop you again and again.
Good Luck,
Bill

william rogers · #9 01-23-2003, 12:25 AM

I found way to clean alge out of pre filters new like clean,after trying everything my wife has under the sink with no luck untill I tried Citrisolve a citric acid base hosehold cleaner I simply held my finger tip over one end and filled it up with Cirtisolve then shook it then rinsed it out with warm tap water and blew it dry with air compressor.....
William Rogers........

PaulH · #10 01-23-2003, 12:32 AM

You can get alge killer at boat supply stores as well as most large truck dealers.

rwthomas1 · #11 01-23-2003, 10:40 AM

Racor makes a biocide as well. www.dieselpage.com DIS has it and are nice to deal with. I have a buddy with a 48ft Hatteras and I have seen his filters turned black with algae. Buggies are a way of life on a boat. He treats the tanks every two-three months and changes the filters. If you treat your tank and keep changing prefilters eventually you will get all of them. Once you have buggies its hard to get rid of them so periodic biocide treatments are a good preventative idea. RT

leathermang · #12 01-23-2003, 11:34 AM

The Algae doesn't really grow IN the Diesel fuel.. it thrives in the line between the (almost)always present water under your fuel and the diesel....I just love the smell of catfish bait... makes me the favorite person of all the wild animals around here... I look like the pied piper with all of them following me around...

Bill, here is a good thread of TCane's about algae

I'm being attacked by algae, help please!

PaulH · #13 01-23-2003, 10:34 PM

Everytime I refuel my boat in the summer (about every two weeks or longer) a little biocide is added. A strong dose is added for the winter lay up. When the boat was new, I didn't do this. Boy, did I have Bugs! Only when I'm on a boat trip using up the fuel every 2 or so days, do I skip a treatment or two. Interesting, though, I've never add anything to my SDL fuel. I think that I have been lucky. By the way, as little as that pre-filter is , you are going to be changing filters for a long time.I would run the fuel down to about 1/4 of a tank, then add a strong dose of biocide (follow directions!), run the car for 2-5 miles to mix it up, then let it sit over night at least, then drain the tank and flush with a gal. or so of clean fuel. Then add biocide every time you refuel for the next month. You will still have to change a lot of filters for a while, but you'l finally get ahead of the bugs. Good Luck.