pmari nailed it. It's microbes.

BTW, we're heading up to Road Atlanta in the morning. Look for the white Ford pickup with Ohio plates in the infield with a canopy, humidor, huge cooler of water, Red Bull and Beer and c'mon over.

I agree it is most likely bacteria. Use the fungicide and be glad you caught it before you got plugged up on the highway!

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Thanks Guys!

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#dieselFLEET
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'97 E300
'99 E300

I'll be on the look out!

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#dieselFLEET
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'97 E300
'99 E300

Added some Startron to the tank this AM before my short journey to work. Let the enzyme action begin!

One of these days I should pull my tank. I've had rust in the neck since day 1, and considering the cleanliness of the car when I bought it many moons ago, I doubt it's been as loved and cared for as I. Who knows what else is in that tank...

I amazes me that 1oz. of Startron treats 32 gallons of fuel. That minute amount of product will coat the neck of the fuel tank before it hits the fuel in the tank, if it makes it that far. It's like using a medicine dropped, letting one drop into a glass of water.

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#dieselFLEET
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'97 E300
'99 E300

Startron is 99.5% or so Naphtha.

I haven't ever been given a proper explanation for what "enzymes" they claim to have in there.

I even spent about $40 to have some shipped to me from a shipyard in Maine before I realized I'd been had.

There are biocides however.

I used one made by Power Service.

I don't know how much of a difference it made but if there was anything living in there it surely perished.

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1993 W124 300D
-297K on the clock as I type this.

Pour in more...they make a fuel tank cleaner which is the same stuff in a larger bottle and the recommended dosage is much greater. I used about 16 oz. of the cleaner per tank in my wagon until I used it up (that's about 1 ounce per gallon). The prefilter immediately turned brown/black and would plug after driving 10 miles, then evenutally, after a couple of tanks it stopped. You can't "overdose" on it by using more than is recommended.

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Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

I would add some biocide as well. My favorite is VALVTECT BioGuard Fuel Microbiocide.

"Specially formulated biocide for marine applications. Test proven up to 90% more effectivethan other products and works in as little as 2–3 hours versus other biocides that require up to 36 hours.

* Kills bacteria quickly
* Breaks up slime
* Prevents filter plugging and corrosion
* Pint treats 480–960 gallons"

Attached Thumbnails

 

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1999 E300DT (131,800) 154,000 Black on Black SOLD

2006 CLK 500 coupe Capri Blue on Grey (zoom,zoom)
47,000mi

04 VW TDI Passat 80,000mi
(Techno)

How to eliminate oil dependency through market-driven approaches.
“We could cut oil use in half by 2025, and by 2040, oil use could be zero,”
The Sound of Diesel Speed
Ode to MB

I used VALVTECT once. Got it from the local marine store, it seemed to work well.

I probably have more miles on high mileage mercedes than anyone and I would never pull a tank to have it cleaned. At least I cannot imagine it.

If you are having plugged filters, a biocide will kill of the microbes etc.

As far as cleaing off thirty years of gunk from the sides of the tank, I think they will keep it from rusting. I have never had any trouble from rust on any of my high mileage mercedes. Never pulled a tank except when I changed my 240 tank for the larger turbo tank.

Save your money to fix things that are broke, IMHO.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.