Was looking at a couple of the old threads on the fuel filter. Was there a particular inline fuel filter people used? I was going to use a e39 m5 fuel filter and try and see if that worked.

 

You do know there is already a filter module in fuel tank?

 

I'm pretty sure the intake manifold from a 2006 Mazdaspeed works on a 55k engine as well, you should pair them up and have a killer set up!

 

would rather not replace whole unit just for a filter. I have one lying around and wanted to try it.

 

While this might be a good idea in theory, what I would be concerned about is the flow rate of the e39 filter. Our fuel system runs on very high pressures. Unless you can find out what the peak fuel pressure the E39 has at 7000rpm, I would be hesitant in using that filter.

That being said, most aftermarket fuel filters tend to be junk anyway and will most likely collapse under full load so choose carefully

 

Jeez a lot of posts on here coming from people who have no freaking clue what they are talking about. Educate yourselves before posting negative posts sometimes

 

Couldn't of said it better myself, I checked the fuel pressure for the e39 and it tops out around 4.9bar. I found out that the old e55 was 4 Bar, not sure what the w211 is. Would it be safe to assume a high pressure filter would work well with a lower pressure system?

 

I always wondered if you could install a inline to "pre-clean" the fuel to help keep our expensive filter/pump combo clean longer.

 

You think that would restrict flow now that it has two points to pass through?

 

Maybe if you installed a high flow filter just to clean out some of the particulates it would work? I'm decent at sliding this thing around the race track but not too good with mods. I just drive it and pay for the thing

 

Pre filtration is useless, cannot be done. The filter is in the tank, no way to pre-filter without creating a choke point.

The OP is talking about removing the stock filter all together and replacing it with one inline outside the fuel tank. That way, you could in theory replace the filter every 5 to 10k miles in as little as half hour or less for less than $100. And in theory the stock sending unit could last as long as the car itself

 

Might be better to just wait until they go and have mbusa replace them. I know one member on here did put one in line and it worked fine for him. Just curious what he used and how it was done.

 

As mentioned our systems run very high fuel pressure. It does NOT sound like a good idea. To swap an E39 M5 fuel filter? Uhmm No.

 

 

The stock w211 E55 idles at ~4.7 bar. That right there eliminates the E39 filter. Will be OK at part throttle, might not fare so well under wot. Then again I do not know what other cars that filter has been used on. If you were to say for example that it is also used on the TT550i, then you will be good with that. For oem type inline filters, I would look at Toyota first imo.
Yes high pressure filter should be OK to work at a lower pressure.

Most who have done the inline filtration use a regular inline filter from Summit and Jegs etc from what I've seen.

 

One more thing, just cos it's starts so high up does not mean it will continue to rise. There is a lot of fuel being dumped in a 5.4l large displacement engine (think American cars) which has a positive displacement blower that makes instant boost. It will bleed pressure from the injectors. Fuel pumps will maintain but will it rise much? Hope some more knowledgeable folks can post their experiences

 

You may be on to something. I see the 550i tops out at 5.7bar. May be a candidate for use. I'll find out and see if toyota has any high pressure fuel systems in their cars.

 

I just got my recall tank installed and wonder about an inline filter.. They say there was a new filter in the new tank but do our E55's have an inline filter along the frame under the car? I'm new to the car and would like to know..

 

You are good to go, since they replaced the tank, they probably replaced the sender as well. The sender contains the fuel filter. You have to replace the whole thing to replace the filter. This is the reason I am looking for inline filters. I think the s600 fuel filter may be a decent candidate as well.

 

I am wondering what the issue is that people are trying to solve. Are you concerned that the in pump filter is not providing enough filtering? If you just add a filter after the in pump filter, it is not going to help that much if at all, unless you are putting it right before the rail and concerned about buildup in the lines ... not sure on the background to the issue here.

Also high pressure does not always fully translate to high flow. If the filter is too small, pressure will be high inside the filter, flow will be low so be careful. Flow rate for the filter is also important.

 

The purpose is to remove the stock filter in the sender, and replace it with a inline unit. This would theoretically allow us to replace the filter independent of the sender, thereby prolonging the life.

 

Easy to do really ...look through my posts its in there some where. Remove factory filter,looped rail and install inline filter in center of fuel rail. It does take some time.

 

I saw, Which filter did you use?

 

This

 

I have seen that and I honestly think that is a waste. You have it like that and you like it so its all good for you. But since this is a looped non-return system, there is no real filtration going on. Fuel fills the rails and pressurizes it, it goes from tank to rail and into combustion chamber. Fuel hits the filter from both ends in your design

Unless you have a return system, your car has no filtration at all