Save yourself up to $200 and some headaches - Electric Fuel Pump PM

Just to update everyone. After getting my pump and filter in, the car is a lot smoother between gears. When rpm drops for clutching and then accelerating, the whole thing seems a lot smoother- no herky-jerky. I thought I maybe had a VANOS problem as well, but everything seems pretty good now.

I hear the smoothness might come from replacing the filter more than the pump, but my pump was super-loud before it finally died, so I'm sure it was not doing great.

Yay for new pump and filter.

Suggest 30k fuel filter interval changes for optimum performance as well.

You should see all the crap that gets trapped in these filters by 60k miles!

Originally Posted by jfoj

You should see all the crap that gets trapped in these filters by 60k miles!

Not always the case, but the point is you don't know.
Took my 78K miles fuel filter apart and it was clean as a whistle. Nothing inside and paper looked like new.

Might be a regional issue, but everything I have take apart or looked at in my area is caked with the fine black powdery substance.

Likely something coming from the tank farms in our area??

The pumps are also supposed to have spin on oil filter looking post filters, but how often do these get changed and how fine are they.

I think I calculated about 2500-3000 gallons goes through the average filter in 60k miles???

Originally Posted by jfoj

Might be a regional issue, but everything I have take apart or looked at in my area is caked with the fine black powdery substance.

Don't doubt your experience. My car ran NY to LA seven times, from crossing up in Canada to down in Louisiana. Filled with every rot-gut pump I could find and filter was spotless. I was kinda surprised.

Man, the VDO pump is LOUD. I replaced mine and immediately noticed I could easily hear the pump from outside the car.

I admit I didn't have the patience to read 23 pages of posts! However, one thing to remember is that your in-tank fuel pump is cooled by the fuel, and overheating is an accelerator of pump wear. if you refill your tank when you get down to a quarter tank, you will keep enough fuel in the tank to cool the pump, and minimize the amount of sludge that gets sucked into your pump from the bottom of the tank. 111,00 mile and still on the original pump.

I was wondering if I could maybe get some help.

I replaced the pump and filter, and the car seemed ok.

Now there is a gurgling sound coming from the tank and I'm using a lot of gas. I put the tank up to 3/4, after driving 10 miles I am at half a tank. There are no codes on the cheap e-bay scanner I have and the car is very smooth.

What might be causing the gurgling sound and loss of mileage? If I should start a new thread for this I can do that.

Thanks,

On an asap basis, I'd want to make sure you're not leaking gas underneath in any way! Take a look up on a lift if necessary.
Something is drastically wrong. Hit anything on the road?


PS---hey, where'd you get the metallic gray-green!!
Best color on an e46 ever.
Have you seen the thread just for this color?

330ci are you really using a lot of fuel?

Are you leaking fuel, this may be more likely, fuel pump seal will usually leak over 3/4 tank. Easy to pull rear seat again, pop access cover and see if you have a heavy fuel smell.

Could be a fuel sender mis-reading as well.

Suggest you read the first post in the 2nd link in my signature and pay special attention to the fuel pump gasket comments.

The read the link for the Hidden OBC Menu and you will be able to see both fuel level senders and see how much fuel is in each half of the fuel tank.

Then also check your total distance you are able to safely drive. Most E46 can get close to or slightly more than 300 miles per tank.

Originally Posted by Stinger9

On an asap basis, I'd want to make sure you're not leaking gas underneath in any way! Take a look up on a lift if necessary.
Something is drastically wrong. Hit anything on the road?


PS---hey, where'd you get the metallic gray-green!!
Best color on an e46 ever.
Have you seen the thread just for this color?

Hi, thanks for your reply.

No visible gas leaks anywhere. It was parked overnight for 2 nights, then all day at work. No gas spots anywhere below it. I went out just now and touched every connection from the tank to the filter and everything is dry. No gas smells outside or inside the car. I have not yet taken off the panel under the seats to check the pump, but like I said nothing smells.

I haven't hit anything, drove non-energetically over the weekend and to work today for a total of maybe 30 miles.

The gurgling can be heard inside the car. When I put my hand on the tank I can feel it bubbling. I double-checked my connections to make sure I plugged the hoses back in the right way on the filter. The blue hose in the middle hole, the other one in the outside hole.

Everything is clean and dry under the car.

Yeah, I love the color; I had to drive out of state to pick it up. Haven't seen the graugruen thread yet.

Thanks again

Regarding the 'am I really using a lot of fuel' I can't say for sure, it's only been a few miles but the gauge went down quickly. Might be a misreading like you said.

Don't overlook installing the pump incorrectly as far as the sender float is concerned. Not too difficult to twist in the wrong way.

and dont trust your gauge either. if you cant find any leeks check your gauge mine is acting up now and missreading then your total safe distance will be incorrect aswell like mine. busy sorting that now.

Originally Posted by Charl_323

if you cant find any leeks check your gauge

When you mention leeks, makes me hungry!

Originally Posted by Stinger9

Don't overlook installing the pump incorrectly as far as the sender float is concerned. Not too difficult to twist in the wrong way.

I'll pull the pump today and check it. The part that scares me is the bubbling in the gas tank.

Sent from my DROID2 using Bimmer App

I'd add a guess there then.
Perhaps a hose on the pump is loose or has a defect that is causing the fuel to pump back into the tank creating an endless loop of gas pumping?

Originally Posted by 76m2002

I admit I didn't have the patience to read 23 pages of posts! However, one thing to remember is that your in-tank fuel pump is cooled by the fuel, and overheating is an accelerator of pump wear. if you refill your tank when you get down to a quarter tank, you will keep enough fuel in the tank to cool the pump, and minimize the amount of sludge that gets sucked into your pump from the bottom of the tank. 111,00 mile and still on the original pump.

Originally Posted by 76m2002

I admit I didn't have the patience to read 23 pages of posts! However, one thing to remember is that your in-tank fuel pump is cooled by the fuel, and overheating is an accelerator of pump wear. if you refill your tank when you get down to a quarter tank, you will keep enough fuel in the tank to cool the pump, and minimize the amount of sludge that gets sucked into your pump from the bottom of the tank. 111,00 mile and still on the original pump.

Many people mention this every day on here (sorry, you are not the first), so I am not picking on you specifically, but people always give this advice about not running below a 1/4 tank because the pump will supposedly pick up more dirt, but the intake for the pump is in a fixed position at the bottom of the pump. By that logic, it is always sitting in the dirt. I am also not sure what sort of dirt people are expecting to find in the bottom of the tank, but mine was clean as a whistle when I changed my pump. I did not see anything settled on the bottom. The screen was also perfectly clear of debris. It was just discolored, while the new one was bright white. This was after 120k miles. Does anyone have a pic of an e46 tank with a lot of junk at the bottom of it? Can anyone say for sure that they saw a lot of crap in the bottom of their tank?
I can agree with the pump needing to be cooled, so you need to keep some gas in there. But this gas tank sludge is somewhat mythical, and if it does exist, then the intake is sitting in it if you are on empty or completely full.
I know it was a problem a long time ago, due mostly to the materials used to make the old fuel tanks, which would start flaking off or the tank would corrode from the inside out. Also, the old independent gas stations were not the cleanest places either. But with the large conviencence store/gas stations, most of them are relatively new constructions, with relatively new modern tanks to store the gas. I just dont think large particle sized dirt is an issue with our gas any more. Small particle dirt I can believe, and that is what the fuel filter is for. I think this is just something that gets passed around and accepted as common knowledge, and no one really questions it.
Cleaning the wheel speed sensors is another good example of this. They are a magnetic pickup, which is not affected by dirt. That is why they use them way out there near the tires and brake dust and dirt. I doubt there was ever an optical type wheel speed sensor, which is the type that may benefit from a cleaning. If there was, I bet it was not used for long. But people still advise this on here every day.

Basically, all sludge that enters your tank is going to exit through the fuel pump, and (hopefully) stop when it gets to the filter. As MJ is saying, that's independent of the fuel level, since the strainer is permanently sitting down there in the sump.

Originally Posted by 3 3 0 C i

I was wondering if I could maybe get some help.

I replaced the pump and filter, and the car seemed ok.

Now there is a gurgling sound coming from the tank and I'm using a lot of gas. I put the tank up to 3/4, after driving 10 miles I am at half a tank. There are no codes on the cheap e-bay scanner I have and the car is very smooth.

What might be causing the gurgling sound and loss of mileage? If I should start a new thread for this I can do that.

Thanks,

I would think that the malfunction would be with the sending unit under the left rear seat, which transfers fuel between the 2 sides of the tank. It has a "sucking jet pump" on it, which could be the gurgling sound you are hearing. Also, the rapid drop in fuel level also points to this. If it is unable to transfer fuel from the left side of the tank, then you are only using fuel from one side, so what would have been 1/4 tank is now 1/2 of the total fuel available. Since the level is measured on the pump side, this would make sense.
It would be parts #2 and #3 in the diagram in the link below:
http://realoem.com/bmw/showparts.do?...73&hg=16&fg=15
It is possible something just pulled loose. It is worth checking at least, before buying parts.

Edit: This actually makes a lot of sense. If something has failed over on the right side, it could be cycling continuously, trying to adjust the levels, which would explain the gurgling noise. IIRC, there is something in the hidden menu that allows you to see the level in each side of the tank. I would check that, and see if one side is not higher than the other by a large amount. Check jfoj's link for the list of hidden menu items you can access.
Also, I was not clear about this, but our cars have a split tank, and a pump in between to keep the levels even. I believe your malfunction is with the system that moves the fuel from the left tank to the right one, which keeps everything level. This is because a single tank would be far too simple for BMW to give us. Not enough possible failure points.