Does anyone else have a loud in tank fuel pump?

[Roadstergal]

Originally Posted by flpnout

I got the car back from the dealership and they confirmed it is the low pressure fuel pump that is going faulty. Parts are on order and scheduled to arrive Friday morning. My service advisor claimed she could not hear anything. I can't believe she could not hear what I was hearing coming from the rear. I asked her to step outside and listen near the rear wheels and still nothing. She ended up getting the shop foreman who confirmed the noise. He then still wanted to compare it to the demonstrator on the lot just to make sure. Demonstrator had no humming at idle.

When I brought my car in last month, they confirmed the noise right away and they overnighted my part so they had the new pump the next day.

I can't believe they went through all of that to confirm the humming. It is well documented that both types of fuel pumps have problems. At least they are going to fix it. I read of one person on one of these boards who have the humming, but it is not showing up on the diagnostics so they won't replace it. I asked my SA whether they went by noise, diagnostic equipment, or both and he said just the humming noise.

[flpnout]

Originally Posted by Roadstergal

When I brought my car in last month, they confirmed the noise right away and they overnighted my part so they had the new pump the next day.

I can't believe they went through all of that to confirm the humming. It is well documented that both types of fuel pumps have problems. At least they are going to fix it. I read of one person on one of these boards who have the humming, but it is not showing up on the diagnostics so they won't replace it. I asked my SA whether they went by noise, diagnostic equipment, or both and he said just the humming noise.

BMW said they plugged it in to diagnose without any fault codes found, but decided they will replace due to the noise. Glad it will be taken care off. They asked if I wanted to keep the loaner until Friday or Saturday and I opted to get my car back since it will just sit outside. Who knows it may get dinged by lot attendants. They said it is safe to drive around anyways.

[BMWZ4]

Thanks for that info Roadstergal. I'll keep my ears open for possible issues.

So far no issues (with anything on the car, except folding mirrors which were promptly replaced). I'm at roughly 4,000 kms / 3 months. I would expect to hit 6 or 7 months of ownership / mileage just prior to storing my car around November 1st.

By the way, with respect to ODBII codes: if you have an ODB reader, check out this forum link from the UK - heck of a LONG list of codes for the Z4. I thought given some in this thread were asking about codes being thrown (re: pump), if they had a reader, they could check themselves.

http://www.z4-forum.com/forum/viewto...it=error+codes

Regards
Dave

[tranquility]

Originally Posted by Chuck76

I had the rear fp replaced after hearing a hum. I had no error codes and the tech diagnosed and replaced the rear and told me that the rear was definitely failing.

I noticed this on mine (just 3 days old) but it is slight whirling noise that comes on and off; probably noticed more now that the fuel tank is emptier. The tech confirmed it and thinks it's the low pressure fuel pump since it is coming from the back of the car and I'll have it checked soon. It is more annoying than anything else.

What I'm curious about is when ppl w/ this prb has the low pressure fuel pump replaced, does the prb actually go away or reoccur? Or is replacement not the solution but something else (software, etc)?

[flpnout]

Originally Posted by tranquility

I noticed this on mine (just 3 days old) but it is slight whirling noise that comes on and off; probably noticed more now that the fuel tank is emptier. The tech confirmed it and thinks it's the low pressure fuel pump since it is coming from the back of the car and I'll have it checked soon. It is more annoying than anything else.

What I'm curious about is when ppl w/ this prb has the low pressure fuel pump replaced, does the prb actually go away or reoccur? Or is replacement not the solution but something else (software, etc)?

Mine didn't completely go away after the in-tank low pressure fuel pump replacement. It seem to have come back. They think now they want to replace the hose that connects to it this Saturday.

[tranquility]

Originally Posted by flpnout

Mine didn't completely go away after the in-tank low pressure fuel pump replacement. It seem to have come back. They think now they want to replace the hose that connects to it this Saturday.

That's what I don't get...why are they seemingly blindly replacing if the prb still comes back...not as it they are replacing w/ a diff model, right?

Please keep me updated bro!

[m999psw]

Hi, I had mine replace within six months from new, and the noise completely went. The car went to the dealers to fix the roof noise (rattles over bumps) and during their test runs ran the fule down to 4 miles left in the tank and the noise is back. At that time apart from saying 'they all do that' they said BMW had sent out a bulliten telling them not to change the lpfp and that new software would be available by the end of June- I am still waiting and the sound is driving me nuts.

Paul

[tranquility]

Originally Posted by m999psw

Hi, I had mine replace within six months from new, and the noise completely went. The car went to the dealers to fix the roof noise (rattles over bumps) and during their test runs ran the fule down to 4 miles left in the tank and the noise is back. At that time apart from saying 'they all do that' they said BMW had sent out a bulliten telling them not to change the lpfp and that new software would be available by the end of June- I am still waiting and the sound is driving me nuts.

Paul

I didn't understand your 1st sentence: they replaced the LPFP but the noise was still there?

[flpnout]

Originally Posted by tranquility

I didn't understand your 1st sentence: they replaced the LPFP but the noise was still there?

I think he meant that it went away.

I'm not sure if I should live with it and wait for the so called software fix or have them replace the hose this time.

All I know if I continue having these issues, I'm going to throw the towel and get my hands on the last of the outgoing M6. Ever since I changed the Z4 wheels that sound occurred immediately right after. I know it has nothing to do with the wheels. I'm just saying.

[teagueAMX]

Originally Posted by tranquility

I didn't understand your 1st sentence: they replaced the LPFP but the noise was still there?

You been doing a lot of research, reading the threads, etc., so you may already be aware of this, but the 35i/35is have two fuel pumps: a lower pressure pump in the fuel tank (LPFP) and a high pressure fuel pump (HPFP) mounted on the n54 TT engine. The fuel tank pump is directly behind the seat. m999psw is noting that while testing his car the dealer managed to use most of the fuel in the tank, which is detrimental to electric fuel pumps. They need fuel for lubrication and cooling. It's a good idea not to let them get below a quarter tank.

The HPFP is the more infamous of the two, but really both are having issues, just not at the same rate. The problem he noted feeds into my theory about why some of BMW’s fuel pumps are failing at high rate. Note my little diatribe here.

http://www.xbimmers.com/forums/showp...6&postcount=57

http://www.xbimmers.com/forums/showp...9&postcount=59

The entire thread

http://www.xbimmers.com/forums/showt...56#post7579356

Don’t get me wrong, I think BMW’s are fantastic cars, but they have an issue with quality control in a few areas, but don't worry you made a good choice buying a Z4!

PS - and don't get caught up in the fuel pump failure related to fuel quality argument!

[tranquility]

Originally Posted by teagueAMX

You been doing a lot of research, reading the threads, etc., so you may already be aware of this, but the 35i/35is have two fuel pumps: a lower pressure pump in the fuel tank (LPFP) and a high pressure fuel pump (HPFP) mounted on the n54 TT engine. The fuel tank pump is directly behind the seat. m999psw is noting that while testing his car the dealer managed to use most of the fuel in the tank, which is detrimental to electric fuel pumps. They need fuel for lubrication and cooling. It's a good idea not to let them get below a quarter tank.

The HPFP is the more infamous of the two, but really both are having issues, just not at the same rate. The problem he noted feeds into my theory about why some of BMW’s fuel pumps are failing at high rate. Note my little diatribe here.

http://www.xbimmers.com/forums/showp...6&postcount=57

http://www.xbimmers.com/forums/showp...9&postcount=59

The entire thread

http://www.xbimmers.com/forums/showt...56#post7579356

Don’t get me wrong, I think BMW’s are fantastic cars, but they have an issue with quality control in a few areas, but don't worry you made a good choice buying a Z4!

PS - and don't get caught up in the fuel pump failure related to fuel quality argument!

Thx. Ya, I went in knowing about this and (knock on wood) think I don't have the dreaded HPFP prb but the LPFP supposedly. I'll let you guys know my diagnosis.

It's a bit weird to have a prb since I'm just 3 days new but I'll take it w/ a grain of salt. Right now, it's just a noise issue, so I'll go from there and see what happens (hopefully not much else!). It comes and goes.

One thing I'm confused about is why should we care about the level of fuel in the tank? I should be able to fill up whenever, whether it's 3/4, 1/2, 1/4 or less. Is there anything official from BMW re this fuel level issue?

The car itself has been great but I know I should get rid of those RFTs as soon as they're worn out...can't seem to get much traction on them during spirited acceleration.

[m999psw]

Sorry if I confused anybody with my response - the noise was there, they changed the pump and it went. A few months later the dealer had the car with no noise, ran down the tank and the noise was back and is still there - and driving me nuts.

I never run the fuel down below 1/4 as a habit from the days when the crap at the bottom of the tank could be drawn into the engine, not an issue anymore apperently.
I'd agree I should not have to worry about when I put fuel in but would rather that than keep losing the car for them to change the pump - with an argument that its normal 'sir' each time.

Paul

[Mr. ///M3 RD]

Originally Posted by teagueAMX

You been doing a lot of research, reading the threads, etc., so you may already be aware of this, but the 35i/35is have two fuel pumps: a lower pressure pump in the fuel tank (LPFP) and a high pressure fuel pump (HPFP) mounted on the n54 TT engine. The fuel tank pump is directly behind the seat. m999psw is noting that while testing his car the dealer managed to use most of the fuel in the tank, which is detrimental to electric fuel pumps. They need fuel for lubrication and cooling. It's a good idea not to let them get below a quarter tank.

The HPFP is the more infamous of the two, but really both are having issues, just not at the same rate. The problem he noted feeds into my theory about why some of BMW’s fuel pumps are failing at high rate. Note my little diatribe here.

http://www.xbimmers.com/forums/showp...6&postcount=57

http://www.xbimmers.com/forums/showp...9&postcount=59

The entire thread

http://www.xbimmers.com/forums/showt...56#post7579356

Don’t get me wrong, I think BMW’s are fantastic cars, but they have an issue with quality control in a few areas, but don't worry you made a good choice buying a Z4!

PS - and don't get caught up in the fuel pump failure related to fuel quality argument!

I am impressed by your research on this issue.

I can see from your write up that you have done a lot of work, devoted a lot of time to get to the bottom of this or at least try.

Your theory certainly makes sense and your write up provides readers with the right ammunition to ask the right questions at the dealer. Well done.

I think what needs to be done now is some follow up to find out how many members (here and on other Z4 forums) to see for example ...

How many members had there fuel pump replaced?

Was it the High Pressure Pump or the Low Pressure Pump?

How many members still have problems after pump replacement?

At what point (milage) the pump failed?

Perhaps you can post a new thread here on this site making reference to your earlier posts on this subject. I am sure many members will appreciate your overall effort on this subject.

Once again I think you made a great effort to find information on this subject and it would be ashamed to now let it idle and not follow up. I am sure you agree the fuel pump issue for the E89 drivers is very important.

Thank you,

Rolf-Dieter

[Roadstergal]

I had my low pressure fuel pump replaced with less than 1400 miles on the car. The humming that I heard never went away. It was constant and the only time that I could not hear it was when I was driving at higher speeds, but if I was stopped at a light or driving on secondary roads, it was always there and it was irking me to no end.

Since I had it replaced, it is perfect. I took TeagueAMX's advice and I never let the tank get less than 1/4, in fact I try to keep it at least half full. I think I may have brought the problem on because I was letting my gas tank go less than 1/4 a few times.

[flpnout]

Originally Posted by Roadstergal

I had my low pressure fuel pump replaced with less than 1400 miles on the car. The humming that I heard never went away. It was constant and the only time that I could not hear it was when I was driving at higher speeds, but if I was stopped at a light or driving on secondary roads, it was always there and it was irking me to no end.

My symptoms are same as yours. Just mine came back as soon as I drove it home after the low pressure pump replacement last Friday. It was interesting that my SA mentioned if I ever heard it again they would order new hose and replace it. I am wondering if that means they heard the noise come back after the replacement. My gas tank was little below half. Like you said, I only hear at idle to low speeds. They want me to bring back this Saturday. Not sure if I should check another dealership. This is frustrating because I was looking forward to autocross it this weekend. I still may and let others hear the noise.

[Roadstergal]

Originally Posted by flpnout

My symptoms are same as yours. Just mine came back as soon as I drove it home after the low pressure pump replacement last Friday. It was interesting that my SA mentioned if I ever heard it again they would order new hose and replace it. I am wondering if that means they heard the noise come back after the replacement. My gas tank was little below half. Like you said, I only hear at idle to low speeds. They want me to bring back this Saturday. Not sure if I should check another dealership. This is frustrating because I was looking forward to autocross it this weekend. I still may and let others hear the noise.

They probably did hear the noise after replacing the pump. I don't know if they replaced any hose at the time they replaced the pump, but it was perfect when I drove it home after they serviced it and five weeks later, it is still perfect. I have to say that the dealership that I bring my car to is very good. I have never had an issue with the service I received on any of my cars in the twelve years that I have been driving BMW's.

I would still go to the autocross. Like you said, it won't hurt the car, it is just so damn annoying. Good luck!

[tranquility]

Originally Posted by Roadstergal

I had my low pressure fuel pump replaced with less than 1400 miles on the car. The humming that I heard never went away. It was constant and the only time that I could not hear it was when I was driving at higher speeds, but if I was stopped at a light or driving on secondary roads, it was always there and it was irking me to no end.

Since I had it replaced, it is perfect. I took TeagueAMX's advice and I never let the tank get less than 1/4, in fact I try to keep it at least half full. I think I may have brought the problem on because I was letting my gas tank go less than 1/4 a few times.

So do you think if you kept your original pump and never let it go below 1/4 you'd be alright? Thx.

[Roadstergal]

Originally Posted by tranquility

So do you think if you kept your original pump and never let it go below 1/4 you'd be alright? Thx.

From what I have read, I do believe so. When I first took delivery of my car, it was fine for the longest time and I pretty much always kept the tank full. I remember one time letting it pretty much go down below 1/4 and it was pretty much soon after that I first starting hearing the humming sound.

Read TeagueAMX's post on the fuel pump. It makes sense. I just know that I am not taking any chances. That humming sound was so aggravating.

[tranquility]

Originally Posted by Roadstergal

From what I have read, I do believe so. When I first took delivery of my car, it was fine for the longest time and I pretty much always kept the tank full. I remember one time letting it pretty much go down below 1/4 and it was pretty much soon after that I first starting hearing the humming sound.

Read TeagueAMX's post on the fuel pump. It makes sense. I just know that I am not taking any chances. That humming sound was so aggravating.

Does that mean, once you let it go below 1/4, even though afterward you tried to keep it above 1/4, the noise was present? So the key is to never let it go below 1/4, not even once?

[teagueAMX]

Originally Posted by tranquility

Does that mean, once you let it go below 1/4, even though afterward you tried to keep it above 1/4, the noise was present? So the key is to never let it go below 1/4, not even once?

The best I can do is give you a story and some antidotal advice.

I've driven cars with electric fuel pumps since the 1980's and they all had 70,000 to 100,000 miles of care free driving as a rule, not the exception.

Recently one of my cars had relatively low miles and the in-tank fuel pump failed. I replaced it myself and everything looked fine. My guess is that even though I was pretty good about keeping the tank above 1/4, sometimes I'd get lazy and let it dip to around an 1/8. There is a short incline on the last leg of my daily commute, so my guess is that on repeated commutes with low fuel going up that incline cause the fuel pump to starve for a few seconds. Maybe it wouldn't have failed if my entire commute had been complete flat.

For some reason, BMW's fuel pumps on one or two of their engines seem to be more sensitive than other cars I driven. Rule of thumb when it get's down around a 1/4 tank fill it up. On the other hand, you have to live your life and drive your car according to conditions. Don't kill yourself if you can't make that happen. That's what the warranty's for.

[tranquility]

^Thx. Strangely, mine was quieter today. Still going to have it checked out though.

[flpnout]

Here is the song and dance email I received from my SA today:

Hello Cris,
*
* I hope you week so far has been treating you well.* I spoke with my technician and the Shop Foreman that heard the noise with you.* The Foreman has advise that we get the car back in here for a few fuel pressure tests before ordering the tank.* Just to verify the noise again, especially since you said it is a tad louder.* I was hoping for this coming Monday when the Foreman and tech will all be here.* If, in fact, it is that suction line inside the fuel tank causing the issue we will be ording the tank from Germany, which would take about 10 days.* So as much as I would love to just order that fuel tank to get it on its way...I cannot until*we confirm the diagnosis due to this specific part and the possibility of it being something else we need to confirm it before we can get it released from Germany. So I am sorry that it looks like you will have to do 2 more trips before this is resolved.* Let me know if I need to try to rustle up a Loaner for you for this Monday 07.19.10 I can get yo in anytime between 7 and 11.* Let me know what works for you.* Thank you again Cris and I am sorry that you are having to be inconvenienced on more than one occasion.
*
Sincerely,
Shana Bates