What is this humming from under the rear seat?
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Junior Member
Joined: Oct 2012
Posts: 51
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07 Ducati S4R & 04 e55
What is this humming from under the rear seat?
Since i bought this car i've noticed it had a hum when running that sounded like a higher frequency than an engine would generate.
Today i hopped in the back seat and low and behold i can hear the hum coming from under the seat. I can even feel it if i put my hand on the seat.
I doubt its the fuel pump, so what could it be? An air pump for the shocks? For the seats? It sounds like its constantly on and its a bit annoying.
Today i hopped in the back seat and low and behold i can hear the hum coming from under the seat. I can even feel it if i put my hand on the seat.
I doubt its the fuel pump, so what could it be? An air pump for the shocks? For the seats? It sounds like its constantly on and its a bit annoying.
Last edited by dvdt; Nov 30, 2012 at 02:56 PM.
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Joined: Aug 2007
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From: Jacksonville, FL
05 White Pano E55, Cadillac CTS-V
Sounds like it is definitely the fuel pump to me. Most likely have a dirty clogged up fuel filter and the pump is struggling due to the restrictive filter making the sound you hear.
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Joined: Aug 2007
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From: Jacksonville, FL
05 White Pano E55, Cadillac CTS-V
A rule of thumb for cars is if driven the typical 12-15k a year you should change them once a year but that almost never happens and official recommendations are higher, I bet some cars go well over 50k miles without changing them.
Last edited by urbamworm; Nov 30, 2012 at 03:46 PM.
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MBWorld Fanatic!
Joined: Aug 2007
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From: Jacksonville, FL
05 White Pano E55, Cadillac CTS-V
Dang, the previous owner of my car replaced the pumps so I haven't even thought about doing filter yet since I haven't driven it that much. I didn't even realize these things don't have an inline fuel filter like other cars under the car or in the bay. Did some quick searcing and found people talking about filters being on the pumps, kinda weird that is the only filters and not a main one inline somewhere.
As for replacing, you pop the seat bottom off and there are caps to the top of the tank on both sides of the car. You open those and pull the fuel pump units out to replace the filter.
As for replacing, you pop the seat bottom off and there are caps to the top of the tank on both sides of the car. You open those and pull the fuel pump units out to replace the filter.
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Joined: May 2007
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From: Hudson Valley, NY
2005 E55 Black, 2007 GL450 Carneol Red
I believe my pumps were changed earlier this year by the previous owner as many of them leak (causing much angst among many of us), but since I'm looking to replace the ring seal (A 211 471 05 79) and possibly lock nut (A 001 990 80 54) soon, I'd like to change the filter(s) while I'm in there.
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Joined: Dec 2006
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From: Florida-Germany-New York
2004 E55,1969 300SEL6.3,2011 ML350 BlueTec Diesel,2005 ML400 CDI
I just checked the EPC for my 2005 E55 and it does not even show a replaceable filter at the pumps ("Delivery Unit with Fluid Level Sensor"), so how does one obtain such a filter?
I believe my pumps were changed earlier this year by the previous owner as many of them leak (causing much angst among many of us), but since I'm looking to replace the ring seal (A 211 471 05 79) and possibly lock nut (A 001 990 80 54) soon, I'd like to change the filter(s) while I'm in there.
I believe my pumps were changed earlier this year by the previous owner as many of them leak (causing much angst among many of us), but since I'm looking to replace the ring seal (A 211 471 05 79) and possibly lock nut (A 001 990 80 54) soon, I'd like to change the filter(s) while I'm in there.
MBWorld Fanatic!
Joined: Aug 2007
Posts: 2,596
Likes: 5
From: Jacksonville, FL
05 White Pano E55, Cadillac CTS-V
I just checked the EPC for my 2005 E55 and it does not even show a replaceable filter at the pumps ("Delivery Unit with Fluid Level Sensor"), so how does one obtain such a filter?
I believe my pumps were changed earlier this year by the previous owner as many of them leak (causing much angst among many of us), but since I'm looking to replace the ring seal (A 211 471 05 79) and possibly lock nut (A 001 990 80 54) soon, I'd like to change the filter(s) while I'm in there.
I believe my pumps were changed earlier this year by the previous owner as many of them leak (causing much angst among many of us), but since I'm looking to replace the ring seal (A 211 471 05 79) and possibly lock nut (A 001 990 80 54) soon, I'd like to change the filter(s) while I'm in there.
With the E55 apparently they don't have a prefilter like nearly every other car out there, and only have the filter on the actual pump/sending unit which is not cheap and is in the around $500 range online.
Last edited by urbamworm; Dec 2, 2012 at 09:55 AM.
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From: Florida
A Merc
Yes it's only on 1 side, although I caution anyone doing it on their own, that these are very very prone to leak and cause the dreaded fuel smell, so be careful, even dealerships make terrible mistakes
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From: Chicago
03 E55 AMG, 06 Harley Road King Custom 06 Ram 2500 Cummins, 97 Firebird Race Car, 88 Cutlass Supreme
At this point with the ongoing nvestigation on the fuel leaks unless I had a problem I wouldn't even think of messing with pulling the unit to replace it. My 03 is on the original setup with 56K miles now. No leaks, no record of any work for a leak. Till NHTSA is done and issues a ruling I see no point in replacing it and opening up the can of leak worms. Worst case you kill a fuel pump from a clogged filter, you have to replace the pump with the filter anyway. Only issue is how is the motor gonna react to starting to go lean from low fuel pressure when under load/boost. Will the computer see what's up and save the motor or will it go lean and pop the motor? haven't heard of one dying this way yet though so again I'm sticking to not messing with it if it's not broke.
Add this junk setup to the list of problems with the fuel tank setup.
Add this junk setup to the list of problems with the fuel tank setup.
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From: Orbiting the planet
This place is a joke.
There's a lot of confusion here about our fuel system setup, so to clear things up:
The tank under the rear seat is a saddle type tank, with a "hump" in the middle to allow clearance for the driveshaft and exhaust.
The car has 2 fuel pumps. Both are located together in the RH (passenger) side of the tank.
The car has 2 fuel level senders, one for each side of the saddle tank. The RH sender is attached to the fuel pump assemblies.
The fuel filter, pressure regulator, and LH sender are all integrated into the LH sender assembly. This assembly has hoses and wires that run inside the tank across to the RH fuel pump assembly.
To replace the filter, you have to change the LH sender assembly, however you also have to remove the RH sender ring/seal/cover to connect and disconnect those hoses/wires inside the tank.
The replacement interval from MB varies depending on the model, and I believe they have changed the spec. several times, from 50k to 100k miles, I would have to check.
The tank under the rear seat is a saddle type tank, with a "hump" in the middle to allow clearance for the driveshaft and exhaust.
The car has 2 fuel pumps. Both are located together in the RH (passenger) side of the tank.
The car has 2 fuel level senders, one for each side of the saddle tank. The RH sender is attached to the fuel pump assemblies.
The fuel filter, pressure regulator, and LH sender are all integrated into the LH sender assembly. This assembly has hoses and wires that run inside the tank across to the RH fuel pump assembly.
To replace the filter, you have to change the LH sender assembly, however you also have to remove the RH sender ring/seal/cover to connect and disconnect those hoses/wires inside the tank.
The replacement interval from MB varies depending on the model, and I believe they have changed the spec. several times, from 50k to 100k miles, I would have to check.
Last edited by E55Greasemonkey; Dec 2, 2012 at 10:24 AM.
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Joined: Dec 2006
Posts: 1,124
Likes: 32
From: Florida-Germany-New York
2004 E55,1969 300SEL6.3,2011 ML350 BlueTec Diesel,2005 ML400 CDI
There's a lot of confusion here about our fuel system setup, so to clear things up:
The tank under the rear seat is a saddle type tank, with a "hump" in the middle to allow clearance for the driveshaft and exhaust.
The car has 2 fuel pumps. Both are located together in the RH (passenger) side of the tank.
The car has 2 fuel level senders, one for each side of the saddle tank. The RH sender is attached to the fuel pump assemblies.
The fuel filter, pressure regulator, and LH sender are all integrated into the LH sender assembly. This assembly has hoses and wires that run inside the tank across to the RH fuel pump assembly.
To replace the filter, you have to change the LH sender assembly, however you also have to remove the RH sender ring/seal/cover to connect and disconnect those hoses/wires inside the tank.
The replacement interval from MB varies depending on the model, and I believe they have changed the spec. several times, from 50k to 100k miles, I would have to check.
The tank under the rear seat is a saddle type tank, with a "hump" in the middle to allow clearance for the driveshaft and exhaust.
The car has 2 fuel pumps. Both are located together in the RH (passenger) side of the tank.
The car has 2 fuel level senders, one for each side of the saddle tank. The RH sender is attached to the fuel pump assemblies.
The fuel filter, pressure regulator, and LH sender are all integrated into the LH sender assembly. This assembly has hoses and wires that run inside the tank across to the RH fuel pump assembly.
To replace the filter, you have to change the LH sender assembly, however you also have to remove the RH sender ring/seal/cover to connect and disconnect those hoses/wires inside the tank.
The replacement interval from MB varies depending on the model, and I believe they have changed the spec. several times, from 50k to 100k miles, I would have to check.
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Joined: May 2012
Posts: 5,081
Likes: 62
From: Harbor City, CA
Mercedes-Benz, Porsche, BMW, MINI and more!
Need more data
Since i bought this car i've noticed it had a hum when running that sounded like a higher frequency than an engine would generate.
Today i hopped in the back seat and low and behold i can hear the hum coming from under the seat. I can even feel it if i put my hand on the seat.
I doubt its the fuel pump, so what could it be? An air pump for the shocks? For the seats? It sounds like its constantly on and its a bit annoying.
Today i hopped in the back seat and low and behold i can hear the hum coming from under the seat. I can even feel it if i put my hand on the seat.
I doubt its the fuel pump, so what could it be? An air pump for the shocks? For the seats? It sounds like its constantly on and its a bit annoying.
roy@pelicanparts.com
Last edited by PelicanParts.com; Dec 5, 2012 at 09:40 PM.
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Joined: May 2012
Posts: 5,081
Likes: 62
From: Harbor City, CA
Mercedes-Benz, Porsche, BMW, MINI and more!
Hmm
Got the VIN#.
Interesting FYI:
The vacuum pump has been superseded
MB# 0008002748
+ MB# 0008000318
+ MB# 0008003515
The fuel tank item #10, and pump item #55, have been superseded.
I would suspect it is the fuel pumps.
I have replaced more of these pumps item #40 and #55 than I want to remember.
* Running the fuel tank on empty all the time = BAD idea = the fuel cools the pump (no fuel = ruined pump)..
* Contaminated fuel.
* Garage queen = setting 3-6 months per year = the gasoline turns to varnish/sludge and ruins the pump.
* Defective unit.
* Road damage.
.
roy@pelicanparts.com
.
Interesting FYI:
The vacuum pump has been superseded
MB# 0008002748
+ MB# 0008000318
+ MB# 0008003515
The fuel tank item #10, and pump item #55, have been superseded.
I would suspect it is the fuel pumps.
I have replaced more of these pumps item #40 and #55 than I want to remember.
* Running the fuel tank on empty all the time = BAD idea = the fuel cools the pump (no fuel = ruined pump)..
* Contaminated fuel.
* Garage queen = setting 3-6 months per year = the gasoline turns to varnish/sludge and ruins the pump.
* Defective unit.
* Road damage.
.
roy@pelicanparts.com
.
