Fuel pump noise gets louder the faster you drive

Tiny
BENLID
  • MEMBER
  • 2000 HYUNDAI ACCENT
  • 120,000 MILES
Hi, had a problem with what we thought was fuel pump failure so removed old pump and replaced with new. Once installed we discovered the problem was not pump failure but an earthing problem. My problem is now the new pump is quiet when idle but the faster you drive the louder the noise, it is a humming noise. Thought maybe new pump was faulty so took out and re-installed old original pump and now that is doing the same thing. Quiet when idle and increasing noise the faster you drive. Noise was never a problem before replacement, pump was only replaced as we thought it had failed. I have removed the pump again, there is no blockage on the sock filter to base of pump and no obvious obstructions. Can anybody please suggest what the issue may be? Any help would be appreciated. Thanks
Monday, December 12th, 2016 AT 6:04 AM

15 Replies

Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
That really does not sound like a fuel pump problem at all. Your descriptions sounds more like a bad wheel bearing than a fuel pump. I have never had any car that you could hear the fuel pump driving down the road, no matter how loud it was. Also, there is no reason for a fuel pump to increase noise with speed. There is no relationship there.
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Monday, December 12th, 2016 AT 7:57 AM
Tiny
BENLID
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Thanks for the reply but I'm pretty certain it is the fuel pump, the noise has only started since fuel pump was removed and reinstalled. Like literally there was no noise the afternoon of replacing pump and noise was immediately there upon first test drive after install.?
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Monday, December 12th, 2016 AT 2:56 PM
Tiny
WRENCHTECH
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The speed of the vehicle has no bearing on the sound of the pump. It works exactly the same at idle as it does when the vehicle is moving so the sound should not change with speed.
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Monday, December 12th, 2016 AT 3:00 PM
Tiny
BENLID
  • MEMBER
  • 9 POSTS
That is very strange. I don't understand how the noise would only come about at the exact time of fuel pump replacement? Is it possible the pump gets louder the faster you drive because it is working harder to supply more fuel or do pumps only operate at one speed?
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Monday, December 12th, 2016 AT 3:08 PM
Tiny
BENLID
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  • 9 POSTS
And thank you for your replies. I appreciate your help
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Monday, December 12th, 2016 AT 3:19 PM
Tiny
WRENCHTECH
  • MECHANIC
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Yes, pumps operate at one speed. They pump 10 times as much fuel as the car uses. The excess returns to the tank.
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Monday, December 12th, 2016 AT 3:20 PM
Tiny
BENLID
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  • 9 POSTS
Okay thank you very much. It must just be a very strange coincidence.
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Monday, December 12th, 2016 AT 3:27 PM
Tiny
BENLID
  • MEMBER
  • 9 POSTS
So something such as a clogged fuel filter or a faulty fuel pressure regulator would not effect the noise? If the pump was the thing making the noise while driving it would make the same noise at idle?
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Monday, December 12th, 2016 AT 3:32 PM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,761 POSTS
The only time it will get louder is when the tank gets low on fuel. A restricted filter could make it louder but that would be constant.
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Monday, December 12th, 2016 AT 3:36 PM
Tiny
BENLID
  • MEMBER
  • 9 POSTS
Same with a fuel pressure regulator too? I have read that if the pump doesn't pressurise the fuel system it can work harder? But that would be constant noise too hey?
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Monday, December 12th, 2016 AT 4:11 PM
Tiny
WRENCHTECH
  • MECHANIC
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The regulator is a bypass type. The regulator has a spring calibrated to a specific pressure and releases everything beyond that back to the tank so the pump has the same speed and resistance at all times.
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Monday, December 12th, 2016 AT 4:20 PM
Tiny
BENLID
  • MEMBER
  • 9 POSTS
So if the system had a leak or wasn't build pressure then the pump would still operate at same speed and noise would not increase or change? Sorry for all the questions, it's just so strange that the noise has only come about since we've touched the fuel pump?
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Monday, December 12th, 2016 AT 4:38 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,009 POSTS
It sounds like you have a problem with the pump installation or the new pump is having a problem, what brand is the replacement pump?
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Monday, December 12th, 2016 AT 9:17 PM
Tiny
BENLID
  • MEMBER
  • 9 POSTS
Hi Ken, we have tried two pumps now. The old original pump was working fine, it was an earthing problem which stopped it from operating. The new pump is a "Goss" this runs quite when car is at idle and during initial prime but it seems that it increases in noise the faster you drive. So we took out the new pump and re-installed the old pump and now we have the same problem. Before we touched the pump, my son swears the noise was never there? Wrenchtech, has given me some advice and has told me the pump only operates at one speed and therefor noise should not increase as you get faster? Whats your advice?
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Tuesday, December 13th, 2016 AT 2:00 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,009 POSTS
Hello,

Wrenchtech is correct the pump only runs one speed so I don't think that is the problem. IT must be a wheel bearing or the tire is cupped which will also cause the noise, check out the guide below which will show a cupped tire.

https://www.2carpros.com/articles/how-car-tires-work

and

https://www.2carpros.com/articles/rear-axle-seal-replacement

Please let us know what you find so it will help others.

Best, Ken

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Tuesday, December 13th, 2016 AT 10:36 AM

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