Filter in the Fuel Tank

[jtwoods4]

Hey guys,

Many people dont know this but there is a fuel filter in the gass tank of w116's. This is a large micron screen that traps larger particles that may be in the gas before it gets to the pre-filter and primary filter at the engine.

Most people never change this. However, several of the online mercedes parts stores sell a replacement filter. I replaced mine today. My car has 105,000 miles on it and the filter was never changed. Here is what the old filter looked like. Below that is what the new filter looks like.

This is an easy maintenance item and can be done in an hour. Make sure your tank is almost empty and then put a catch bucket under the old filer before you remove it. You will spill some diesel doing it but no big deal.

[jtwoods4]

Sorry I forgot to mention that you will need a special tool to remove the filter. The folks at mercedes source sell the tool with the filter. That is where I ordered mine from. Here is a link.

http://mercedessource.com/store/123-116-126-diesel-fuel-tank-screen-removal-and-replacement-kit

[philpot]

The outlet on my 280S tank looks very similar. Do the petrol cars have this filter also?

[jtwoods4]

I am only familiar with the 617 Diesel engine models. Sorry.

[Casey]

The outlet on my 280S tank looks very similar. Do the petrol cars have this filter also?

Yes I believe they do.  I have a spare 280E tank I can check tomorrow, if that part's still intact.

[Casey]

The outlet on my 280S tank looks very similar. Do the petrol cars have this filter also?

Yes I believe they do.  I have a spare 280E tank I can check tomorrow, if that part's still intact.

Check that - I was curious so I just went and checked.  Yes, it's there.  I don't have the "special" tool (which I believe is just a 42mm socket from memory - I only have up to 36mm presently) so I couldn't pull it, but I stuck a screwdriver into the hole and felt the inside of the filter (I also have a new filter so am familiar with them).  I am not sure whether it would be the same part number or something different for the type of fuel, but the size seemed to be the same as the diesel ones.

[oversize]

I believe all W116s have the screens and they are the cause of many breakdowns and a rough idle issues.  Basically the pump get starved.  Without the special tool is not such an easy job (I might have to get one)....  And it's probably a good idea to replace the hose while it's on the bench.

BTW are the screens all the same or do they vary between models?  Is petrol the same as diesel?  What's the part number?

[Casey]

Without the special tool is not such an easy job (I might have to get one)....

What seems to be the problem with a normal 1/2" drive socket you can buy about anywhere for under $10?

[Big_Richard]

.

[Casey]

The one on my 6,9 was just aas clogged but it was orange sludge presumably rust from the fuel retailers underground storage tanks. The inside of the fuel tank was as new otherwise.

How do you see the inside of the tank effectively?  The 280E tank I have was filled with VERY rusty petrol when I pulled it, and it sounds like there's some chunks still stuck in there.  Looks great from the outside.   I'm hoping there's some way to recover it, because my 200D has a reduced-capacity plastic tank that I'd like to replace.

The 200D's in-tank filter is also so badly clogged, that if the fuel gets down to around a quarter tank, it no longer flows at all, and the car dies and won't start again until I add more fuel (switching the two fuel lines under the hood will buy a couple miles though in a pinch).

[oversize]

42mm sockets aren't that easy to find here and if you do they're $$$.  And that's all assuming you can undo the fuel hose....

[Nutz]

I just used a pair of channel lock pliers when i changed my 300D intank filter.



Sludge snot at the bottom of tank. 

[Big_Richard]

.

[Nutz]

Did that too.Way less messy as well.

[TJ 450]

I got away with not removing the tank(s), but I have only done it with the subframe removed or by the hose fitting, so the easiest option other than buying the modified socket from Mercedessource is to remove the tank if you can't do either of these.

Do try to undo it with the hose fitting though, as that works a lot of the time (I think it is 22mm).

Tim