I can't believe how much of a difference a clean fuel filter makes

Some of the most neglected items on my car definitely had to have been the fuel filters. I slapped some new ones in this afternoon and was amazed at how much the change effected the engine's performance. The car ran well before, yet it now idles smoother, revs more freely, and has more seat of the pants feel of power (wishful thinking). Upon inspection of the clear plastic filter, I noticed sort of a brownish yellow hue, could that have been algae?
Another benefit was spraying the engine with Engine Brite and hosing it down. Some how this must have cleaned the tach sensor and I now have a fully functional tach!

Tomorrow: my first valve adjustment! (thanks Thomaspin for your excellent website!)

In well over 800,000 miles of MB diesel maintenance, my experience has been that changing both fuel filters every 25,000 miles will prevent the situation you encountered.

The only exception to this would be bad luck that causes you to get a REALLY BAD tank of fuel somewhere. I have never had that bad luck,

As far as algae goes, I have seen it before. You will say BB sized grey particles in the pre filter. When you see these, simply pour a can of bio gard in the tank to kill the algae.

This is all you need to know to keep your tank and filter system in shape.

Good luck,

[Gurkha]

Here in India, I change my fuel filters every 5000 km, this is with regular dose of DALF additive from ELF. I have also attached a sedimenter which collects all the algae and gig particles as well as tar. You should see what ends up in the filters and the sedimenters after 5000km. It is a lesson to be learnt. I have both the felt pre-filter as well as the paper filter. It is good to spend on filters than servicing injector and pump.

[P.E.Haiges]

Larry,

Where can I get Bio Gard?

P E H

[lrg]

PEH,
I've seen it in marine supply stores like West Marine (if you have those there). As bad as the problem can be in our cars it's often worse for boaters.

Hotskillet,
If you have some algae in your tank and treat it with Bio Gard, you'll likely see more algae in your filter as it dies and floats down your fuel lines. Keep an eye on your clear (inline) filter and be prepared to change it more often. A couple of spare filters in your glove compartment is a good idea.

LRG

Seriously, There can't be that much moisture in our fuel, there's no light and a petroleum distillate can't be all that hospitable to any organism!

[lrg]

Obviously there is a type of algae that loves diesel (and just like us doesn't like gasoline), it just needs a little water to make it grow. Who knows, it may be related to the stuff the oil recovery teams use to eat up oil spills from tankers. Fortunately, this algae doesn't grow very rapidly so if you are using up the fuel relatively quickly you should't have a problem. If you tend to let the car sit then that's another story. Buying fuel from high volume stations helps cut the risk too. If you plan on storing the car for more than a couple of weeks I'd recommend a dose of Bio Gard and filling the tank just to be on the safe side. A lot of diesel additives have a biocide that will keep algae at bay but usually aren't strong enough to get rid of it if you have a bad case.

I bought bio gard at a local tractor dealer.

Have a great day,

Nobody wrote about that, but there is an initial filter at the bottom of diesel tank that should be changed every 50 000 km, according to my country (Costa Rica) MB dealer.
My 300d is just coming from US, as part of my initial update, I changed this filter and cleaned the tank. When done, I felt the car working more freely.