Fuel pump dead?

[Balavay]

I know that there are a lot of threads dealing with this common issue and I've done a lot of reading on various forums. I just keep thinking that I might be missing something...

Vehicle: 2005 X5 4.8, 82k miles
Symptoms: Cranks very strong but does not start
Troubleshooting:
- new battery installed a week ago and kept on the trickle charger overnight (consistent 12.5-12.8 V)
- checked fuse #47 (in the glove box)
- checked fuel pump relay K96 (on top/behind glove box fuses) by swapping the working horn relay below it
- used a paper clip in place of the fuel pump relay (pins 30 and 87) but no sound from the pump, car still does not start
- with the key turned to position 2, I do not hear anything at the fuel filler door with a removed cap OR at the back seat where the pump is
- tested the fuel pump connector at the pump, shows 0 V with no key and 11.2 V with key in position 2

Would anything else beyond what I checked above prevent the fuel pump from running (well, besides a dead fuel pump)?

Also, is the fuel pump supposed to make a sound every time the key is turned to position 2? For example, turning the key to position 2, then back to position 0 within a few seconds, then again to 2 and there would be the priming sound every time?

Thanks in advance for any help. And I do realize that I might already have an answer (dead fuel pump) and my questions are a waste of time...

[Deansbimmer]

The pump primes for a second or two every start cycle. Sounds like you've found a dead pump, especially since there's voltage and no activity. You can get a new genuine BMW pump assembly for 270 if you look around.

[Joshdub]

Sounds likely. I'd check for fuel pressure at the fuel rail(s) first though.

[RFaber]

If there is no whiring sound in the first two seconds after switching the key on, (just before the start position) then i strongly suspect a fuel pump, especially after all the other tests you performed. a fuel pump is loud enough to be heard from inside the cabin, with the rear seat lifted up. at least its an easy fix!

[Balavay]

Thanks for all responses and info. It took me a few days to get to Harbor Freight for the pressure tester. I was going to rent one from AutoZone, but for $18 I figured it is a good diagnostics tool to have anyway.

Originally Posted by Joshdub

Sounds likely. I'd check for fuel pressure at the fuel rail(s) first though.

I've checked the pressure at the schrader valve on the fuel rail, got 0 (zero) with key in position 1 or 2, and while cranking the engine. I've repeated the test a few times, always 0. Pinching the line does not change it. Initially, as I was attaching the test hose to the test valve, I saw a bit of fuel coming out. But then at the end, when I removed the test hose, I pressed the pin on the valve and there was no fuel coming out at all. Does this confirm a bad pump? Or could it be the pressure regulator inside the filter? Or anything else?

Originally Posted by Deansbimmer

The pump primes for a second or two every start cycle. Sounds like you've found a dead pump, especially since there's voltage and no activity. You can get a new genuine BMW pump assembly for 270 if you look around.

There is definitely no sound (ever). I was just hoping that it could be the filter only... I already got the fuel filter about 6 months ago from TheBMWpartstore as I was planning some preventive maintenance. I believe that they have the best price for the fuel pump too (part# 16116768357 is $272.41). I get all my parts from there unless the local dealer matches the price. I've seen various auctions on eBay, but who knows how 'genuine' those are.

Originally Posted by RFaber

If there is no whiring sound in the first two seconds after switching the key on, (just before the start position) then i strongly suspect a fuel pump, especially after all the other tests you performed. a fuel pump is loud enough to be heard from inside the cabin, with the rear seat lifted up. at least its an easy fix!

I agree that it is an easy fix and have no problems replacing it (I will replace the filter too), as I do most of repairs on the car. I was just hoping to avoid the $300 part cost

[Deansbimmer]

It's uncommon for a pressure regulator to fail on these since they're inside the filter, so they're usually replaced with relative frequency. Additionally, when they fail they usually fail to reduce pressure and flood the engine, not overly restrict pressure.

Also, I love BMWpartstore, I always order from them. Sometimes I can get the genuine part for about the same as aftermarket. They're great.

[upallnight]

Originally Posted by Balavay

Thanks for all responses and info. It took me a few days to get to Harbor Freight for the pressure tester. I was going to rent one from AutoZone, but for $18 I figured it is a good diagnostics tool to have anyway.


I've checked the pressure at the schrader valve on the fuel rail, got 0 (zero) with key in position 1 or 2, and while cranking the engine. I've repeated the test a few times, always 0. Pinching the line does not change it. Initially, as I was attaching the test hose to the test valve, I saw a bit of fuel coming out. But then at the end, when I removed the test hose, I pressed the pin on the valve and there was no fuel coming out at all. Does this confirm a bad pump? Or could it be the pressure regulator inside the filter? Or anything else?


There is definitely no sound (ever). I was just hoping that it could be the filter only... I already got the fuel filter about 6 months ago from TheBMWpartstore as I was planning some preventive maintenance. I believe that they have the best price for the fuel pump too (part# 16116768357 is $272.41). I get all my parts from there unless the local dealer matches the price. I've seen various auctions on eBay, but who knows how 'genuine' those are.


I agree that it is an easy fix and have no problems replacing it (I will replace the filter too), as I do most of repairs on the car. I was just hoping to avoid the $300 part cost

Just buy a universal Bosch fuel pump from HK. Less than 40 bucks and you can't beat the shipping cost.

300LPH External Inline Fuel Pump Replacment 044 for Bosch 0580254044 Universal | eBay

[squidzilla]

Originally Posted by upallnight

Just buy a universal Bosch fuel pump from HK. Less than 40 bucks and you can't beat the shipping cost.

300LPH External Inline Fuel Pump Replacment 044 for Bosch 0580254044 Universal | eBay

That seems like the best way to go. What is the benefit of buying the pricey OEM fuel pump. I figured it was because that was the only one that would fit. This makes me want to get one of these for my x5 mt.

[Balavay]

Wow, great find, it does say universal!

[Deansbimmer]

The 044 pump in that eBay listing isn't exactly a plug and play, stress-free solution. The 044 Bosch pump has a threaded/hex fuel pickup intended to be screwed into the fuel tank supply/pickup/pipe. The OEM pump has a pressed-on pickup sock on the bottom of the pump. You won't be able to install a pickup sock onto the eBay pump, which is a necessity.

I'd prefer to buy a new OEM pump at $272 because you get the whole assembly, not just a pump. You get the whole housing, tube, electrical, sender, and pump/sock....You get to replace all of the old brittle plastic and tubes, which is worth the peace of mind and ease of installation, IMO.

You may be able to find a pump the same diameter, length, and output tube/ voltage connector configuration that has a round, same diameter input for a pickup sock as the stock pump, but I haven't found one. I don't know about you guys, but I'd rather spend my time fishing than trying to hunt down a part and jerry rig in order to save a few bucks.