XSeries-forum

Hi Guys,

When I bought my car back in December it had problem where as the fuel gauge would not go past half full, incorrectly telling me that I had 300 odd miles left and half a tank fuel of diesel. I would think I had loads of fuel left, but then would get the "bing,bing,bing" and 'Fuel Injection System' fault followed by the engine stalling. (Because it actually had no fuel in it...)

I discovered that because it worked perfectly from Full->Half that the 'High Level' fuel sender unit was working ok, but the lower Fuel Sender Unit (with the float at the bottom) that does Half->Empty was not working correctly. I ordered a new one for £67 and fitted it myself.

Fitting was an easy job and over the next few days I noticed the needle had gone past the halfway mark (which it had never done before) and seemed to be working fine...

That was until a few days later when the needle reached the quarter tank mark and showed I had 159 miles left to go. Shortly after I got the "bing, bing, bing" 'Fuel Injection System' error again shortly followed by the engine stalling. Luckily I had a full can of Diesel in the boot, so filled it up and off I went.

Since then I've had the Fuel Sender out again and fiddled around with stuff here and there to try and get it working correctly. Unfortunately the only way I can really check this myself is to drive the car and see if it stalls or not...Which is not ideal. (Although I have my trusty full can in the boot)

I put £50 of Diesel in it last week and have watched the fuel range figure (which I'm aware is just a basic calculation of fuel level/mpg) and fuel needle go down as they should.

Yesterday me and the mrs took the dog out to Shrewsbury for a walk up the Wrekin, on the way back I noticed the Fuel Guage was on a quarter full and the Range displaying 161miles. I watched the guage like a hawk all the way down to 159miles (and taking the drive pretty easily) and sure enough a few miles later and I got "bing, bing, bing" 'Fuel Injection System'

So again I filled it up with the can and put another £50 in at a local station. I just now know that when my car shows a quarter of a tank (159 miles) it really means empty... That issue aside the car drives like a dream. I've never had a problem starting it and performance has always been spot on.

Then I read a thread on the USA 5 series forum where a guy had the same problem. He worked out that the Fuel Filter was preventing the fuel pump/syphon system from sucking out the last quarter of a tank of fuel. (So instead of the fuel tank being empty but showing a quarter tank, it actually does have a quarter tank in it...it just can't get to it). He claims that repalcing the £15 Fuel Filter has sorted his issue.

Here is a bit of info from the guy's thread: (Interesting Read)

Ok, for anyone that's interested (anyone who's contemplated changing their fuel pump because they aren't getting enough power at higher rmps, or because your car is acting like you just ran out of gas, but your gauge says you have over a quarter tank left) - I was going to change my fuel pump thinking that would create higher pressure in the return fuel line so the sucking jet pump (siphon) would work to take the gas over to the right side of the tank. I decided first to change my fuel filter since it was only fifty bucks (verses a $250-330 fuel pump) and I have 80k miles on my car anyway, so it probably needs it.

So, after the fuel filter change (without changing the fuel pump) I have ALL my power back through the whole range of rpms! I think my car might be faster now than ever since I've had it (I bought it with 40K miles on it). Also, wha-la! My sucking jet pump is working!!! I think, anyway. I used the hidden OBC test #6 (see wiki for how to do this) to track my fuel level in each side, and now the left side' just got sucked completely dry and all the gas is in the right side (I had a little less than half a tank when I switched my fuel filter.

I'm going to fill my tank up all the way now to see if everything is working right. If the fuel filter solved the problem, the left side of the tank should always empty first.

A funny thing happened the other night while I was out on the town with my girlfriend and my sister and her boyfriend. On the way driving home (this was before I replaced the fuel filter) I hadn't been paying attention and the fuel level started getting down to quarter tank level. The car started choking and sputtering and I realized we were going to have to hike to get gas (i've had a gas can in my trunk lately... for some reason ) Earlier I had been showing off the little trick I learned with the OBC, and it happened to be running as we were running out of gas. Seeing all that gas in the left side of the tank gave me an idea. There was a median going down the middle of the highway, so I waited until we rolled up to the next intersection and then flipped a hard (sliding) U-turn. All the gas sloshed up over the hump and into the right side of the gas tank, the car stopped choking and took off and we were able to make it across town to the next gas station!!!

Now i'm more than happy to do this, I've found the Fuel Filters for £15 and fitting seems ok-ish (but a bit of a PITA). So I thought i'd ask here if anyone has any input before I buy and fit it?

Any help guys?

I personally can't see how the fuel filter can affect how much fuel is drawn from the tank.
But it is probably overdue for changing anyway. So no harm giving it a go!

Yeah that's what I thought. It seems something along the lines of the last quarter tank is in a low down part of the fuel tank. The 'dodgy' Fuel Filter throttles the required pressure from sucking out this last bit, but not as much pressure is needed to suck fuel from Full-> Quarter...

It kind of makes sense.

Also, just checked the thread again on the next page and seen a few more posts like this:

Thank you so much for posting your gas tank problem and the resolution!!! I was about to get rid of my 2001 325ci after no auto shops were able to fix my gas tank problem (the same problem you had before). I gave it a try and asked the auto shop to replace my fuel filter and it WORKSSS!!!!! My car runs even better than before and I was able to use the ENTIRE tank of gas!!! Thank you soooo much!!!

Well, today I fitted my shiny new Bosch Fuel Filter, but unfortunately it didn't help the issue

It was a long shot, but after 120k on the original one, I guess it could have done with a replacement anyway!




I don't know much about the workings of the fuel system, so I'm hoping someone in the know will be able to offer me some advice at this point.

After fitting the fuel filter, i drove the car about 20 miles until it hit the 1/4 tank mark again and i watched the 'Range' like a hawk. It dropped to 169 miles, and then slowly crept up to 170,171,172,173 and by that time I had already assumed that it hadn't fixed my issue. (as before it would go down to about the same Range, and then start slowly creeping back up)

I drove around expecting it to cut out at any moment, but it didn't.... I drove it all the way home (another 10 or so miles) and made it back onto my drive trouble free. I turned off the engine and thought maybe it actually had worked.... But just to check I tried to start the engine again straight away and it wouldn't start. (Gauge still showing 1/4 tank and 170-ish miles):



After it wouldn't start I got into the Hidden OBC Menu to check the Fuel levels (Test NR 6):

AFAIK this is saying that the Left Side has 0L of fuel in, the Right side has 23.1L of fuel in and the total fuel is 23.1L:


I then whipped off the back seats and took out both the Fuel senders. Sure enough the Left side (Passenger side) was empty and the Right side (Drivers) had some fuel in it, not much though.

So what does this mean then? Is it a duff pump on the Drivers side Fuel sender unit? or is it actually working since the Left side has been sucked dry?

It's really confusing me, I've already replaced the Passenger side Sender and the Fuel Filter, but the Drivers side sender has the fuel pump attached to it and is £200+ so if I replace this I want to be pretty sure that's the problem.

Any help would be great!

Cheers

Unsure what they exactly did to repair mine as it was done under warranty, but they said that they had to change the aux fuel pump which pumped the fuel from one side to the other, this is because the fuel tank is an upside down U shape. I believe it is located under the seat area.

Phill


Sent from my iPod touch using Tapatalk

Thanks Phill,

After reading a whole load of threads, TIS guides, and websites regarding the Fuel Guage problems on varios BMW's last night, I woke up this morning and went straight out to the car to have one last fiddle.

It was -1 and the car was covered in ice! But I just got stuck in and totally dissembled the Fuel senders, both driver and passenger. I removed everything I could and went over it all with a fine tooth comb.

I had my arm fully into the tank up to my elbow in freezing cold diesel and moved around all the hoses to make sure there was nothing jammed or out of place. I took off and cleaned up all the connections on the top of the senders as well as fully removing the senders themselves and making sure all the resistor slide contacts were cleaned up and working ok.

I found the syphon hose and turned on the ignition and it started to slowly dribble out, I put my thumb over the hose hole and could feel it sucking harder at my thumb followed by a few gurgling noises. I took my thumb off and the flow was instantly better and it was more of a steady stream of fuel being pulled trough from the other side of the tank rather than a dribble.

I lubed up all the O rings and gaskets as best I could and fit the whole lot back together.

Turned the car on and saw this:

(Before I did any work on the car, it was telling me I had 1/4 tank of fuel and 167 Miles on the Range)



I was gobsmacked that it was now working! I have never seen the red light come on in my car ever before!

Since then, I put £15 in just to check the lower end of the tank and it all seems to be working fine now!

(It's a bit of a PITA though since I ordered and paid for a replacement Drivers side Sender & Pump from a scrappy which is being delievered Monday, but it seems now that I don't actually need it after all! )

Anyway, I'm not exactly sure what it was that fixed it since I did so many things at once. It could have been the syphon, it could have been a hose that wasn't properly seated, or something blocking the sender float before maybe?? But either way, i'm over the moon it's working and even more happy that I did it myself!

The fact that I've just fitted a new fuel filter is probably a good thing too, BMW say they last the life of the car, but loads of website I looked into yesterday (BMW) mention a noticable perfomance improvement at higher revs just by fitting a new filter. They also say that when they removed their old filters at 50k/60k/70k etc, loads of thick black sludge came out!

Here's a few pics just for good measure anyway!

Need Urgent assistance from members or anyone here.

I'am having tremendous migraine with my BMW X5 4.6is Right Hand Drive. This is the 3rd time am facing the same problem. Initially my Fuel gauge was not showing the right fuel level. Brought to the authorised BMW dealer. The replace the right tank float. It only took a few days when it just go back to the initial problem. Upon checking, it show as per BMW authorised dealer "claimed" the float broke. Picture attached.

I would appreciate and thankful if any members or any once who could advice in rectifying this issue step by step.

Thank yo beforehand for the kind assistance rendered.

No picture - on either of your threads