07 GL450 fuel pump
Thread Starter
MBWorld Fanatic!
Joined: Jun 2010
Posts: 2,755
Likes: 628
From: Emmett, ID, USA
2007 GL450
07 GL450 fuel pump
Had a "soft" power loss this morning. If you lose ignition, you'll get a sudden, sharp loss of power. This was gentle enough that I couldn't figure out what was wrong at first.
Put it in neutral and coasted to a safe stopping place. Cranks but won't start.
A symptom of a weak fuel pump is if it sits with the ignition on, you can build up some pressure in the fuel rail. If I sat for a few seconds with the ignition on and then tried to start, it would go to a weak idle and then die.
Checked fuses and tried swapping relays (I think the horn relay is the same), but no luck.
Fortunately near my favorite indy. Diagnosis came back quick: fuel pump. $1,100.
I figured it was a goner before too much more time went by. 160K miles.
Put it in neutral and coasted to a safe stopping place. Cranks but won't start.
A symptom of a weak fuel pump is if it sits with the ignition on, you can build up some pressure in the fuel rail. If I sat for a few seconds with the ignition on and then tried to start, it would go to a weak idle and then die.
Checked fuses and tried swapping relays (I think the horn relay is the same), but no luck.
Fortunately near my favorite indy. Diagnosis came back quick: fuel pump. $1,100.
I figured it was a goner before too much more time went by. 160K miles.
Last edited by eric_in_sd; Oct 17, 2019 at 12:59 PM.
Thread Starter
MBWorld Fanatic!
Joined: Jun 2010
Posts: 2,755
Likes: 628
From: Emmett, ID, USA
2007 GL450
It looks to be a bunch of work but not terribly difficult. Right?
Junior Member
Joined: Aug 2016
Posts: 18
Likes: 9
From: USA, California
2010 ML350 4Matic, 2013 GL450 4Matic
It is fairly straight-forward.
1) Remove the rear right passenger seat. There is cover with 2 torx. Then 4 - 16mm bolts and seat is out.
2) Remove door step cover. Remove 2 plastic covers for seat hinges.
3) If you have the rear seat entertainment dvd drive - remove metal cover: 3 torx bits, 10 mm nut. Another torx screw that supports the back of the dvd unit. Then unclip front dvd cover and remove 2 more screws. Slide dvd out towards front of the car.
4) use chisel or prybar to remove the fuel pump cover. unclip fuel pump connector.
5) use this tool from amazon to unscrew the top mounting ring 6) pull out old fuel pump and install new. I have ordered a Delphi fuel pump from FCP euro. Fuel pump. $176
7) I have re-used original lock ring and seal. The seal included with Delphi fuel pump is not good. There is also a lock ring and seal mounting kit available for another $50. I have tried to use that Delphi seal but as a result had a huge gas spill under the car as seal did not seat properly. Original seal looked good and I have reinstalled it. Make sure you have less than half a tank of gas to make install easy.
8) When mounting new pump watch for level sensor not to get bent. It is best to have someone hold the pump down to seat in the groove to prevent it from rotating.
9) Drive to gas station without covering the hole and fill up the full tank to check for leaks. If all is good - use some polyurethane adhesive to seat the cover back.
Done
1) Remove the rear right passenger seat. There is cover with 2 torx. Then 4 - 16mm bolts and seat is out.
2) Remove door step cover. Remove 2 plastic covers for seat hinges.
3) If you have the rear seat entertainment dvd drive - remove metal cover: 3 torx bits, 10 mm nut. Another torx screw that supports the back of the dvd unit. Then unclip front dvd cover and remove 2 more screws. Slide dvd out towards front of the car.
4) use chisel or prybar to remove the fuel pump cover. unclip fuel pump connector.
5) use this tool from amazon to unscrew the top mounting ring 6) pull out old fuel pump and install new. I have ordered a Delphi fuel pump from FCP euro. Fuel pump. $176
7) I have re-used original lock ring and seal. The seal included with Delphi fuel pump is not good. There is also a lock ring and seal mounting kit available for another $50. I have tried to use that Delphi seal but as a result had a huge gas spill under the car as seal did not seat properly. Original seal looked good and I have reinstalled it. Make sure you have less than half a tank of gas to make install easy.
8) When mounting new pump watch for level sensor not to get bent. It is best to have someone hold the pump down to seat in the groove to prevent it from rotating.
9) Drive to gas station without covering the hole and fill up the full tank to check for leaks. If all is good - use some polyurethane adhesive to seat the cover back.
Done
Thread Starter
MBWorld Fanatic!
Joined: Jun 2010
Posts: 2,755
Likes: 628
From: Emmett, ID, USA
2007 GL450
10) Change underwear.
Post is much appreciated. Not many take the trouble to enlighten others. Respect. FWIW the shop that did my pump used silicone sealant.
I'm a little surprised Delphi did not include a good gasket. I would not be surprised at all if Delphi made the part for MB - after all, they make the coils. The gasket on my install was a separate line item. OEM for both.
If I may add a few cautionary items:
Highly recommend keeping a fire extinguisher, preferably halon, around when working with gasoline. Make a BRIEF attempt at putting the fire out and then get the hell out of there.
Gasoline vapors are heavier than air; they may collect in the footwell. Ventilate the passenger compartment and the garage.
Disconnect the battery before opening the tank. Reduce the chances of some switch spark somewhere making you one sorry dude. The risk is not so much that the gas in the tank ignites, but that vapors flash burn; the sudden release of heat can leave your skin falling off. This happens with propane vapors sometimes, and the results are gruesome.
Post is much appreciated. Not many take the trouble to enlighten others. Respect. FWIW the shop that did my pump used silicone sealant.
I'm a little surprised Delphi did not include a good gasket. I would not be surprised at all if Delphi made the part for MB - after all, they make the coils. The gasket on my install was a separate line item. OEM for both.
If I may add a few cautionary items:
Highly recommend keeping a fire extinguisher, preferably halon, around when working with gasoline. Make a BRIEF attempt at putting the fire out and then get the hell out of there.
Gasoline vapors are heavier than air; they may collect in the footwell. Ventilate the passenger compartment and the garage.
Disconnect the battery before opening the tank. Reduce the chances of some switch spark somewhere making you one sorry dude. The risk is not so much that the gas in the tank ignites, but that vapors flash burn; the sudden release of heat can leave your skin falling off. This happens with propane vapors sometimes, and the results are gruesome.
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Super Member
Joined: Jan 2007
Posts: 622
Likes: 202
From: CA
11 ML550, 95 Supra TT, 14 Audi S4
Mine died about 8 months ago. Leading up to the failure, it was taking more cranking to get the car started, which is consistent with the pump taking longer to get fuel pressure up. It finally wouldn't restart after I turned the engine off while waiting in a pharmacy drive through. I had no idea how bad the average driver is at backing up until I saw more than one completely fail at trying to back up about 10' in a straight line to the drive through window (I was blocking the lane while waiting for a tow truck). I was pretty sure it was the pump, but I didn't want to pay for a second tow from my house to the dealer if I couldn't figure it out so I just had the driver tow to the dealer. Ended up being ~$1,000 for a new pump and filter.
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Senior Member
Joined: Apr 2014
Posts: 332
Likes: 70
2007 GL450
It is fairly straight-forward.
1) Remove the rear right passenger seat. There is cover with 2 torx. Then 4 - 16mm bolts and seat is out.
2) Remove door step cover. Remove 2 plastic covers for seat hinges.
3) If you have the rear seat entertainment dvd drive - remove metal cover: 3 torx bits, 10 mm nut. Another torx screw that supports the back of the dvd unit. Then unclip front dvd cover and remove 2 more screws. Slide dvd out towards front of the car.
4) use chisel or prybar to remove the fuel pump cover. unclip fuel pump connector.
5) use this tool from amazon to unscrew the top mounting ring Tool $20
6) pull out old fuel pump and install new. I have ordered a Delphi fuel pump from FCP euro. Fuel pump. $176
7) I have re-used original lock ring and seal. The seal included with Delphi fuel pump is not good. There is also a lock ring and seal mounting kit available for another $50. I have tried to use that Delphi seal but as a result had a huge gas spill under the car as seal did not seat properly. Original seal looked good and I have reinstalled it. Make sure you have less than half a tank of gas to make install easy.
8) When mounting new pump watch for level sensor not to get bent. It is best to have someone hold the pump down to seat in the groove to prevent it from rotating.
9) Drive to gas station without covering the hole and fill up the full tank to check for leaks. If all is good - use some polyurethane adhesive to seat the cover back.
Done
1) Remove the rear right passenger seat. There is cover with 2 torx. Then 4 - 16mm bolts and seat is out.
2) Remove door step cover. Remove 2 plastic covers for seat hinges.
3) If you have the rear seat entertainment dvd drive - remove metal cover: 3 torx bits, 10 mm nut. Another torx screw that supports the back of the dvd unit. Then unclip front dvd cover and remove 2 more screws. Slide dvd out towards front of the car.
4) use chisel or prybar to remove the fuel pump cover. unclip fuel pump connector.
5) use this tool from amazon to unscrew the top mounting ring Tool $20
6) pull out old fuel pump and install new. I have ordered a Delphi fuel pump from FCP euro. Fuel pump. $176
7) I have re-used original lock ring and seal. The seal included with Delphi fuel pump is not good. There is also a lock ring and seal mounting kit available for another $50. I have tried to use that Delphi seal but as a result had a huge gas spill under the car as seal did not seat properly. Original seal looked good and I have reinstalled it. Make sure you have less than half a tank of gas to make install easy.
8) When mounting new pump watch for level sensor not to get bent. It is best to have someone hold the pump down to seat in the groove to prevent it from rotating.
9) Drive to gas station without covering the hole and fill up the full tank to check for leaks. If all is good - use some polyurethane adhesive to seat the cover back.
Done
thanks for sharing.
seems I could not find the correct fuel pump item in rockauto. feul pumps in rockauto are all priced below $40 and have different appearance.
