So you have never used Startron for diesel? I have, and it gets rid of the Algae, without plugging the filters and stranding you like biocide will.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Correct, never tried it, but perhaps I will now! Which stores usually carry it?

Algea grows in fresh water ponds and requires sunlight for life (photosynthesis, carbon dioxide, nutrients). Microbes don't like sunlight and are what grow in water and eat the fuel diesel fuel tanks. Neither the MB literature nor any of the fuel treatment websites discussed call it algae. Sorry, terminology is a pet peeve of mine. I'll bet if you pour diesel fuel into a pond with algae growing, it will kill them pretty quick!

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

It DOES kill fungus so you needn't use anything else .

Initial treatment , when faced with clogged filters and stalling out while driving , should be a heavy over does , the clear plastic intake screen may plug but that's easy to blow out or replace by the side of the road .

My '84 300CD had the worst case of fungus I or anyone else I've met (I'm a Mechanic) ever had (maybe why it was junked) , Startron made it go .

Agreed , if you have the time and 4MM socket , removing the in tank screen and cleaning it , is a good idea too .

Often the fuel sender's tube gets full of fungus crud that's hard to fully kill off , I take them out and carefully clean , re install and have no further problems .

Lastly , steaming out the fuel tank won't kill the fungus ! it'll remain in crevices and grow back rapidly .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Thanks for the advice....I know how to change the fuel filter,
but that's about it. So I don't know how to do what someone suggested:
"drain the rest of the tank and then remove and clean the tank strainer. Fill with fresh diesel, put in another treatment of StarTron and you should be good"
If this is a straight forward procedure, great. But not sure how to do this....

There is a level of contamination which merits removal of the fuel sending on top of the tank unit and strainer which is on the tank's bottom. I think those decision are relative to the owner's experience. I appreciate your position.

In my opinion, you may have a difficult time cleaning them. The tools required are something you may never use again. The Factory Service Manual gives a clear picture and description of how these are removed. Find a way to gain access to it.

However, you may be able to remedy this entire problem for less than $50 with StarTron. It's worth a try. Just put a bottle in the tank at next fillup and pick up some primary (clear) filters.

Change them before they shut the engine down.

__________________
84 300SD
85 380SE
83 528e
95 318ic

The black precipitates of "Asphaltenes: the Cholesterol of Petroleum " come from the fuel itself.
Agreed. X2
Try going through a couple of more treatments with a big bottle of Star Tron Tank Cleaner.
Readily available at any good marine goods store or online...I got mine at West Marine.
Star Tron is like a dietary change for treating cholesterol deposits.
Biodiesel will also cleanout your fuel system, but it will dissolve rubber fuel lines...so I'd stick with the Star Tron.
Remember you are dissolving years and years of buildup which will take a bit of time.
If that does not work then consider removing/cleaning the tank strainer (fuel sender, tank, fuel lines)...which would be like surgically removing cholesterol buildup.

Removing the tank strainer is fairly easy.
Make sure to drain all the fuel from the tank by siphoning it out of the fill hole.
If the tank strainer is clogged, draining the fuel by disconnecting the fuel outlet hose on the bottom of the tank can leave quite a bit of fuel in the tank.
Removing a clogged tank strainer from a tank that is not empty can result in an unexpected fuel shower.

Diesel Giant has a good pictorial DIY at this link.

__________________
78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022

I'd make sure I got the StarTron product for diesel engines. I can't say the stuff for gas is different but I wouldn't take the risk.

__________________
84 300SD
85 380SE
83 528e
95 318ic

To help get the fuel out to clean the strainer, a transfer pump is cheap and cheerful. They are everywhere. I backed the car up on ramps, pumped the fuel out and yes, some will pour out when the strainer is unscrewed. Good info is avail on this site about removing/cleaning strainer, a good way to search is by typing " peachparts:fuel strainer" etc in google.

Attached Thumbnails

 

I used StarTron with a double dose at first, and it did seem to smooth out the rough start ups just a bit, but .....that was the end of its magic. I still have rough start ups, and the car still has problems going up steep hills.

I might have to have the tank cleaned.

1991 300d, 207k

Just change the strainer and keep dosing with startron.
Most likely the strainer is covered in slime slowing fuel flow at high demands.
I use startron in my home made biodiesel , I find an ounce in half a tank (30 litres) on my w210 gives the fuel the same kick as a dose of 2ehn ie very smooth engine and a big increase in power .
Stick with it.

If your strainer is badly clogged and you do not want to remove it to clean it (big messy job)

1. add a dose of Star Tron

2. attach a long wooden stick to a tooth brush with wires (do not use tape- it will unravel and drop the tooth brush)

3. remove, fuel sender. go in fuel sender hole and brush off the gunk that is clogging the strainer.

4. drive the car. use up the tank. repeat the brushing of strainer if necessary and add more Star Tron. Eventually the gunk will be all broken up into small particles, pass the filters and get burned in the engine.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Or do it the lazy way push 5 psi air through the supply line back to the tank from the engine bay before the addition of your additive.

__________________
92 e300d2.5t
01 e320
05 cdi
85 chev c10

That will work also, but maybe not as well as a toothbrush, which will get more of the gunk off around the strainer, and break it up into smaller pieces. Some people do not have an air compressor so not and option.

If you do use an air compressor, make sure tank is low and the fuel cap is off, so that:

1. you do not blow fuel out the filler neck

2. fuel does not blow back at you when you let go of the blower tip.

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Linda ;

Are you clear now on what to do or wanting more detailed account of the tools necessary to go the deeper route ? .

Remember : for Startron to work properly you need to fill the tank fully , topping it off so the stuff is all the way up in the tank , fungus grows every where , just the worst bits settle to the bottom .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

There are write-ups to do this on the net, just google it and you should be able to find one. Consider dumping in a can of diesel purge as well to dissolve goobers. It works well.

For $600 I'll fly out to LA R&R your tank and flush it out.

Boiling out a tank here costs $50.00.

Maybe this guy is contemplating new patio furniture at home, or a down payment on a boat!

__________________
Strelnik
Invest in America: Buy a Congressman!

1950 170SD
1951 Citroen 11BN
1953 Citroen 11BNF limo
1953 220a project
1959 180D
1960 190D
1960 Borgward Isabella TS 2dr
1983 240D daily driver
1983 380SL
1990 350SDL daily driver alt
3 x Citroen DS21M, down from 5
3 x Citroen 2CV, down from 6