Fuel Filters flow direction on 95 540 e34

[Redtail]

This is a serious note, though it may sound trivial. The fuel filters on my 540 are perpendicular to the engine and it is not clear which direction the flow should go. I have gotten several answers from different people that are contradictory.

Does anyone know if the flow goes towards the passenger rear tire or away from the passenger rear tire?

Will the filters function if installed the wrong direction?

Thanks in advance.

[Kalevera]

Do a search, mate -- we talked about this a few weeks ago, IIRC.

In short: the filter should have an arrow on it indicating flow. The arrow points towards the engine, not towards the tank.

Best, whit

[paul p (chi-town)]

Do a search, mate -- In short: the filter should have an arrow on it indicating flow.

Uh, little more complicated than that.
Silly v8s have two parallel filters. This arrangement was of course dropped on the e39. *rolleyes*
As best i remember (~2 years) flow goes from the outside of the car (passanger side) towards the center. To be sure, simply follow the lines back a ways, you should be able to figure out which one goes to the tank and which to the engine. The arrows go in the direction of fuel flow.
Since i hadn’t discovered PBblaster yet the bolt holding the bracket snapped and i couldn’t rig it back up.
Sooo i’m only running one filter held up w/ a big ass hose clamp. Since it is kinda due for replacement (20k miles) i am considering simply throwing on a larger single filter from a 535.

At least it's in a relatively easy place to get too. On the 3er it's location above the trans is a total PITA.

94 530iT&A---92 325i.......”Hang up & Drive!”.....no SERiously
”Bet that phone call doesn’t seem that important now, eh?” Nov 20, 2004

[txp135]

Could anyone who did fuel filter recently confirm the direction of flow? It does look like it flows towards the center of the car. Both filters (540i) go in the same direction correct? Thank you.

[shogun]

There is/are only filters from fuel tank to the engine room.
In the return line is only the charcoal filter which is in the engine room.

What is so difficult?
You have the old ones installed. Look at their installation and just install the new ones the same way, arrow towards engine room.

[txp135]

Thanks, you are right. The arrows on the old filters were covered. After I remove them I can see which direction the old ones were.

[markus]

just make sure the old ones werent installed backwards like mine were by the PO. Car sure ran great and had more power after that. also get new hose clamps. my oringal ones were pretty much toast. and i broke 2 out of 4.

[txp135]

I got new hose clamps but the old ones look okay and are of better qualities so I left them in. However, I couldn't tighten the 10mm nut because it's stuck on the bolt and the bolt is loose. I can't even see what's up there. Do I just go to the dealer and get new bolt/nut and cut the old ones out?