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

The sucking jet pump stuff is on the left. Both sides have level senders, and their outputs are added together to read total fuel level, so the gauge on the dash should read the same whichever side the fuel is in. If they both work. You can read them separately in the hidden menu.

Sucking jet pump actually extends from one side of the tank to the other. So it's on both sides.

Been a long time since I replaced an E46 fuel pump, but on my E39 M5, the pump had to be seated correctly as there was a round pipe with an O-ring that came from the left side siphon pump as I recall?

Is there anything like this on the E46?

Also as for fuel levels, usually once the composite tank level(s) get to about 1/2 tank, the left side of the tank pumps down quickly due to the siphon pump and usually should be empty except due to hard cornering, then the tank pumps down very quickly again.

Use the Hiddern OBC Menu link in my signature to figure out if you are actually transferring fuel from the left side of the tank properly.

Originally Posted by Wolrab

The sucking jet pump stuff is on the left. Both sides have level senders, and their outputs are added together to read total fuel level, so the gauge on the dash should read the same whichever side the fuel is in. If they both work. You can read them separately in the hidden menu.

Yep. I got my right and left confused. O__o
I corrected it. You are too quick on the replies!

Originally Posted by Stinger9

Sucking jet pump actually extends from one side of the tank to the other. So it's on both sides.

Well yes, because of the whole balancing the fuel load thing. I was fixing that too, but again, you guys are responding too fast! Give me a minute to read what I wrote, and sort out the brain farts!

Originally Posted by jfoj

Been a long time since I replaced an E46 fuel pump, but on my E39 M5, the pump had to be seated correctly as there was a round pipe with an O-ring that came from the left side siphon pump as I recall?

Is there anything like this on the E46?

Also as for fuel levels, usually once the composite tank level(s) get to about 1/2 tank, the left side of the tank pumps down quickly due to the siphon pump and usually should be empty except due to hard cornering, then the tank pumps down very quickly again.

Use the Hiddern OBC Menu link in my signature to figure out if you are actually transferring fuel from the left side of the tank properly.

Yep, there is something like that, but I don't believe there is something to line up on the pump side. There is the sending unit, and the sucking jet pump, which keeps the fuel level balanced. I was adding that in to my post while you were writing this. It is all there now.

Don't you guys have work to do? I lead a life of luxury, and can respond all day, but shouldn't the rest of you be working?

Originally Posted by MJLavelle

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.

Thank you that was spot-on. I reseated the plug for the sucking jet pump and started the car. It gurgled for one second then I heard the sucking jet pump whrrrr.

The gurgle is gone, the tanks are once-again level with each other according to the diagnostic and the gas that disappeared on the gauge came back.

Thanks again for your input.

edit: 'sucking jet pump' rhymes with the words I was using before you told me about this.

Originally Posted by MJLavelle

There is the sending unit, and the sucking jet pump, which keeps the fuel level balanced.

Don't you guys have work to do? , but shouldn't the rest of you be working?

Sucking jet pump does not keep the fuel level balanced. It keeps the right side saddle tank filled up.

I quit my job so I could respond here all day long! And now I hear you're not grateful?

Originally Posted by 3 3 0 C i

I reseated the plug for the sucking jet pump and started the car. It gurgled for one second then I heard the sucking jet pump whrrrr.

Sucking jet pump is only a tube. Tubes don't whirr. Sucking jet pump did not whirr.
Only active part in the tank is the fuel pump with a motor.

Originally Posted by Stinger9

Sucking jet pump is only a tube. Tubes don't whirr. Sucking jet pump did not whirr.
Only active part in the tank is the fuel pump with a motor.

OK Cool. I guess I just heard the whine of the fuel pump then. Either way problem is solved.

Thanks a ton all of you who helped me out.

Happy Thanksgiving!

Damn. Im 202k, 2nd owner (the first owner didnt replace the fuel pump), and as soon as I get my coolant system overhauled i'll be replacing my fuel pump. Its either luck, or using premium non-generic fuel and changing my filter regularly has extended the life of the pump. This might sound crazy, but before I change my filter I run a few gallons of E85 through my tank once its on Empty. Research has shown that it disolves some deposits left behind by the fossil fuel. The car runs fine on E85 up until around 4k rpm where the pump/injectors cant keep up and power slightly drops off. Im not looking for warnings and criticism for using ethanol, i'm fully aware of the risks and 'possible damage' that ethanol fuels can cause to non flexfuel vehicles. Just adding my 2¢.

any idea what THIS noise can be? I heard it when i parked the car after driving to work about 25 min, but hasn't heard it since...
It came from near DRIVER side REAR wheel. (could hear it from inside the car too)
outside was about 40 F.
Tank was half full. Car has been sitting for about 5 days before this.
no other symptoms- starts, idles and runs fine. 36k miles. auto.
haven't heard it the next 3-4 times

video: (listen to washing machine like noise - sloshing/gurgling whatever):

I am at a bit of a loss for ideas on this, but if the car was turned off when you heard this noise, it is likely an Evap pump to test the vehicles Evap system?

If the car was still running, could be Evap pump or noise from the Sucking Jet Pump in the left side of the fuel.

The car was running - idling in park. no noises after turning car off.

Hey I was wondering if any one knew what the volume and .pressure coming out of the fuel pump should be for a 2001 325i thanks guys

Sent from my PC36100 using Bimmer App

Pressure should be around 40psi static.
Not sure of volume.
Think pressure will tell you most of what you need to know.

Stinger,

50 PSI is what I recall??

I will try to check for sure.

Update - 3.5 Bar = 50 PSI.

But if you really think you need to check it, probably should just replace the fuel filter & pump!

Originally Posted by jfoj

Stinger,

50 PSI is what I recall??

I will try to check for sure.

Update - 3.5 Bar = 50 PSI.

But if you really think you need to check it, probably should just replace the fuel filter & pump!

50 psi at all fuel evels ?

Sent from my PC36100 using Bimmer App

3 bar is the quote for my car.

http://tis.spaghetticoder.org/s/view.pl?1/06/04/54

My Bentley manual has 3.5 Bar or 50.76 PSI +/- 2.9 PSI for the MS 42.0 & MS 43.0 Engine.

Volume of 1.12 liter or 1.16 qt for 30 seconds.

I think the comment from Spaghetticoder is just a caution to let you know that the fuel pressure is "approxmately" 3 Bar?? Not sure this is an actual spec or measurement?

Ms45?