Fuel Pump Configuration?
Thread Starter
Junior Member
Joined: Jul 2010
Posts: 15
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BMW 318ti
Fuel Pump Configuration?
Hello,
I am going to be working on a 2003 E320 soon (140,000+ miles) and was informed by the shop that it was brought to that the fuel pump needs replacing. I don't see much info on this site about dead fuel pumps, so they must be pretty good
I have yet to do my own diagnostics....
So from what I understand there are two fuel pumps? One on the passenger's side (US) with an integrated level sensor. And another on the driver's side with it's own level sensor, and it also contains the fuel filter. Is this correct? The two pumps don't look the same, so do they have different functions. Does one boost the pressure higher? Just doing some research before I receive the car. Thanks!
EDIT: OK, I did find the official MB prodedure on this website. They do not refer to the driver's side unit as a pump, only a "Fuel filter with integrated fuel pressure regulator". ??
I am going to be working on a 2003 E320 soon (140,000+ miles) and was informed by the shop that it was brought to that the fuel pump needs replacing. I don't see much info on this site about dead fuel pumps, so they must be pretty good
I have yet to do my own diagnostics.... So from what I understand there are two fuel pumps? One on the passenger's side (US) with an integrated level sensor. And another on the driver's side with it's own level sensor, and it also contains the fuel filter. Is this correct? The two pumps don't look the same, so do they have different functions. Does one boost the pressure higher? Just doing some research before I receive the car. Thanks!
EDIT: OK, I did find the official MB prodedure on this website. They do not refer to the driver's side unit as a pump, only a "Fuel filter with integrated fuel pressure regulator". ??
Last edited by E365; Jul 5, 2010 at 04:27 PM.
Super Member
Joined: Apr 2005
Posts: 666
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From: Boston, MA USA
03 E320 -wife's car now; 07 Porsche Boxster S - my toy
There is one fuel pump on these cars and it's located in the passenger side of the fuel tank. The fuel filter is on the driver's side. Both the pump and filter have level sensors on them because the tank has essentially two sections to it. Power comes in to the fuel filter and then routed (with fuel lines) to the other side of the tank for the fuel pump.
When I changed mine, I did it when the fuel level gauge was only showing a single line to minimize the amount of gas in the tank. Since you'll have both tank covers open to do this job, safety is most important. Good luck.
Regards,
paul...
When I changed mine, I did it when the fuel level gauge was only showing a single line to minimize the amount of gas in the tank. Since you'll have both tank covers open to do this job, safety is most important. Good luck.
Regards,
paul...
Super Member
Joined: Apr 2005
Posts: 666
Likes: 4
From: Boston, MA USA
03 E320 -wife's car now; 07 Porsche Boxster S - my toy
Regards,
paul...
Thread Starter
Junior Member
Joined: Jul 2010
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BMW 318ti
Got the car and I think I also narrowed it down to the pump. The pump receives 12v for the "quick prime" when you first turn the ignition to ON (roughly two seconds). It also recieves 12v during cranking. There seems to be no life from the pump during that inital prime, even with my ear about three inches away.
I found RMEuropean had a good price on one.
The car actually has 180,000 miles, so it certainly could have died.
I found RMEuropean had a good price on one.
The car actually has 180,000 miles, so it certainly could have died.
MBWorld Fanatic!
Joined: Sep 2005
Posts: 6,192
Likes: 242
From: Albuquerque
'10 CL550, '12 GL550
Get a subscription to WIS or buy a Service DVD.
A little left over high school auto shop knowledge isn't going to work with a Mercedes. Plus, you have ZERO guarantee anything you find on forums will be accurate or complete.
DIY still means you have to own the tools.
http://www.startekinfo.com
A little left over high school auto shop knowledge isn't going to work with a Mercedes. Plus, you have ZERO guarantee anything you find on forums will be accurate or complete.
DIY still means you have to own the tools.
http://www.startekinfo.com
Super Member
Joined: Apr 2005
Posts: 666
Likes: 4
From: Boston, MA USA
03 E320 -wife's car now; 07 Porsche Boxster S - my toy
Got the car and I think I also narrowed it down to the pump. The pump receives 12v for the "quick prime" when you first turn the ignition to ON (roughly two seconds). It also recieves 12v during cranking. There seems to be no life from the pump during that inital prime, even with my ear about three inches away.
I found RMEuropean had a good price on one.
The car actually has 180,000 miles, so it certainly could have died.
I found RMEuropean had a good price on one.
The car actually has 180,000 miles, so it certainly could have died.
I've attached a technical bulletin from Airtex (large fuel pump manuf) with some pointers on troubleshooting an electric fuel pump.
Regards,
paul...
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Thread Starter
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BMW 318ti
Thanks for the info paulv!
I just installed a new fuel pump today and that took care of it; runs perfectly. I roughly followed the MB procedure that I found on this site, but it's still pretty basic. Similar to the BMWs I've been working on for about a decade.
I tested the old pump once it was removed and when given power (extra 12v car battery) it will only run after you give the assembly a little bump.
As for a service manual, I agree, to a point. I've used the Bentley Publishing brand BMW manuals for many years. They are very helpful for many things, but there are still basics that apply to every car.
I just installed a new fuel pump today and that took care of it; runs perfectly.
I roughly followed the MB procedure that I found on this site, but it's still pretty basic. Similar to the BMWs I've been working on for about a decade.I tested the old pump once it was removed and when given power (extra 12v car battery) it will only run after you give the assembly a little bump.
As for a service manual, I agree, to a point. I've used the Bentley Publishing brand BMW manuals for many years. They are very helpful for many things, but there are still basics that apply to every car.
Last edited by E365; Jul 8, 2010 at 05:08 PM.
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Super Member
Joined: Apr 2005
Posts: 666
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From: Boston, MA USA
03 E320 -wife's car now; 07 Porsche Boxster S - my toy
Regards,
paul...
MBWorld Fanatic!
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From: Albuquerque
'10 CL550, '12 GL550
For example, Mercedes will introduce you to CLIC clamps.
Junior Member
Joined: Apr 2009
Posts: 29
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From: Mississippi
2002 E320 4matic & 2003 E320,
How did you test the 12 volts to the pump during spinning the engine over? Specifically which wires did u use to confirm 12 volts? Where did u access the wires to test them? thanks!! Jay
Junior Member
Joined: Apr 2009
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From: Mississippi
2002 E320 4matic & 2003 E320,
I didn't see that rule!! Ha. This is participating in another post to get information from someone else that may have been experiencing the same trouble. The guys in this discussion may not be aware of my questions. This reply will trigger an email to them. Thanks. Jay
