New Fuel Pump Humming

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Herbiedog
still on the production line
Posts: 48
Joined: Mon Nov 26, 2012 4:47 am
Passat model: B6 2.0 TDI 170hp
Location: Swindon

New Fuel Pump Humming

Post by Herbiedog » Sun Apr 15, 2018 8:27 pm

I'm in need of a bit of advice. My fuel pump on my 2007 B6 2.0 TDI failed a month or so ago so had it replaced straight away. Since the replacement there has been a humming sound coming from the rear underside/under rear seat area where the pump is situated. I have told the independent garage who fitted it about this and been told 'Give it a few days, see how it goes. If there's no change bring it in'. Not the best response so I will take it back in and get them to sort it but...
Having read similar threads the hum is something associated with the pump about to fail? So my question is did they botch the job and if so is there anything on the pump that would indicate its age if I have a look at it myself and also is there a simple fix for the hum if this is a new pump. It should be new. I paid £180 for the part and labour. There is no change in performance as far as I can tell.

Fanx. :-bd
2007 VW Passat Sport TDI 2.0 170HP DSG Saloon Mocha Brown

DMitch16
B6
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Joined: Sun Jul 08, 2012 11:03 am
Passat model: B6 Sport 170 DSG
Location: Rustington, West Sussex

Re: New Fuel Pump Humming

Post by DMitch16 » Sun Apr 15, 2018 9:20 pm

Never used to hear mine - now that I've changed it I hear it every day. Was probably un-noticable before but as you are now aware of its existence and location, your brain tells you to specifically identify it while your car is running. Most of the time I stop hearing mine after a while when driving but always on start up and first run nowadays.

Also a great deal of relevant in tank fuel pump threads state that there is a possibility that the pump has failed if you CAN'T hear a hum, not if you can so contradictory to what you have read.
Mad Mitch
B6 2007 2.0 Tdi 170 Sport DSG, BMR Engine, Phone Kit, Alarm chirps, Fogs as DRLs, Rain Auto Closure + VCDS MicroCAN, Double Oil Pump Drive Failure! Still Going 200K Club

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ShaneB
B2
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Passat model: B6
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Re: New Fuel Pump Humming

Post by ShaneB » Mon Apr 16, 2018 2:30 pm

Not a Passat but changed the pump in my Impreza and the new pump is notably noisier than the old one although once running you can't hear a thing over the exhaust so doesn't bother me. Could be the old one was quiet because it was failing, new pump is running better hence noisier.
Volkswagen Passat B5.5 130 Bhp, 1.9 TDI Sport Wagon, Silver Blue Metallic. 200K and still going strong (SOLD).
Mistaken dabble with a Civic CDT-i (SOLD)
2010 Volswagen Passat B6 140 Bhp, 2.0 TDI Highline Wagon, Silver Grey Metallic

Herbiedog
still on the production line
Posts: 48
Joined: Mon Nov 26, 2012 4:47 am
Passat model: B6 2.0 TDI 170hp
Location: Swindon

Re: New Fuel Pump Humming

Post by Herbiedog » Mon Apr 16, 2018 7:56 pm

Thanks for the replies.That is very interesting but a little disappointing as mine is humming all the time!
I have to say it sounds too loud to be correct but at the same time it's not excessively loud but anyone who hears it agrees it doesn't sound right to hear this in the car. I cant really hear it above 40 mph but doing under this around 30mph and below in town I can and it is always present. The old pump did not do this in the year I had the car prior to the pump being changed which I obviously got used to.
2007 VW Passat Sport TDI 2.0 170HP DSG Saloon Mocha Brown

passartist
B6
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Passat model: b5.5 4motion est
Location: Cambridge

Re: New Fuel Pump Humming

Post by passartist » Wed Apr 18, 2018 8:39 pm

The TDI in tank pump is a lift pump and there is no reason to hear it other than if you have removed the cover and you have your ear right near the cover.

If a pump is noisy it is beginning to break up and fail. A new pump is ALWAYS quieter. I'd suggest they've mounted it improperly or have left off some of the bushing material. You can't compare the sound of an EFI lift pump to a TDI they run at a tiny percentage of the pressure so are not audiable when the engine is running

DMitch16
B6
Posts: 864
Joined: Sun Jul 08, 2012 11:03 am
Passat model: B6 Sport 170 DSG
Location: Rustington, West Sussex

Re: New Fuel Pump Humming

Post by DMitch16 » Thu Apr 19, 2018 1:28 pm

passartist wrote:
Wed Apr 18, 2018 8:39 pm
The TDI in tank pump is a lift pump and there is no reason to hear it other than if you have removed the cover and you have your ear right near the cover.

If a pump is noisy it is beginning to break up and fail. A new pump is ALWAYS quieter. I'd suggest they've mounted it improperly or have left off some of the bushing material. You can't compare the sound of an EFI lift pump to a TDI they run at a tiny percentage of the pressure so are not audiable when the engine is running
I beg to differ - mine is a brand new unit fitted 6 months ago. It is heard 'priming' for want of a better word at first ignition on. Once the car has started it is a very faint hum, barely noticeable but there nevertheless. I always run no less than a quarter tank so it is always submerged but I have heard good but noisy pumps on cars constantly at the fuel reserve level, as the emptiness of the tank resonates the noise of the exposed motor (which is not good for the pump motor whatsoever). Sure on most cars the pump being under a padded seat with a plastic cover over the hole and a plastic top and seal should not be heard.

Perhaps it is sensitive hearing as I can even hear my oil pump working from the inside of the car and could on all my other cars (it's a very faint bloop, bloop, bloop if anyone wants to know). I have diagnosed many faults with engines correctly based on what they sound like because I know what they SHOULD sound like.
Mad Mitch
B6 2007 2.0 Tdi 170 Sport DSG, BMR Engine, Phone Kit, Alarm chirps, Fogs as DRLs, Rain Auto Closure + VCDS MicroCAN, Double Oil Pump Drive Failure! Still Going 200K Club

passartist
B6
Posts: 725
Joined: Sun Dec 01, 2013 12:15 am
Passat model: b5.5 4motion est
Location: Cambridge

Re: New Fuel Pump Humming

Post by passartist » Thu Apr 19, 2018 10:31 pm

So not that different from what I posted then...
DMitch16 wrote:
Thu Apr 19, 2018 1:28 pm
Once the car has started it is a very faint hum, barely noticeable but there nevertheless.

DMitch16
B6
Posts: 864
Joined: Sun Jul 08, 2012 11:03 am
Passat model: B6 Sport 170 DSG
Location: Rustington, West Sussex

Re: New Fuel Pump Humming

Post by DMitch16 » Fri Apr 20, 2018 9:52 pm

passartist wrote:
Thu Apr 19, 2018 10:31 pm
So not that different from what I posted then...
DMitch16 wrote:
Thu Apr 19, 2018 1:28 pm
Once the car has started it is a very faint hum, barely noticeable but there nevertheless.
Perhaps not and yes a distinctively noisy pump is something to be concerned about as you have mentioned. Even years before the last one gave up the ghost, I could not hear what I do now with the new one (identical full unit replacement) but this may just be a psychosematic reaction and my brain filtering the engine noise out in favour of the pump and since doing the first balance shaft replacement, the oil pump too.
Mad Mitch
B6 2007 2.0 Tdi 170 Sport DSG, BMR Engine, Phone Kit, Alarm chirps, Fogs as DRLs, Rain Auto Closure + VCDS MicroCAN, Double Oil Pump Drive Failure! Still Going 200K Club

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