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"Tick" from fuel pump???

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wolfie
Silver Member
Posts: 264
Joined: Wed Jul 06, 2011 11:56 am
Drives: 6R0 - 1.2 Tsi SEL
Location: North Staffs

"Tick" from fuel pump???

Post by wolfie » Mon Jun 04, 2018 7:30 pm

Sitting in the car fiddling with the dashcam, I had with the engine running with door open. I happened to notice that I could here a "Ticking" noise coming from beneath the car. I had a little listen and it appears to be coming from the area where the fuel filter is located just by the side of the fuel tank. I got a long screwdriver and placed it on the fuel filter and I can hear quite a loud tick. (if I increase the revs even a tiny bit the "tick" disappears)

Now I know the Tsi's have a lift pump in the tank and a high pressure pump driven from the engine. I stuck my "listening stick" on the engine pump and while I can hear it tapping away it sounds like what I'd expect to hear. Now if the lift pump is getting ready to fail might the clicking be the first signs? I think the TSi lift pump also has a PWM pump controller thingy just above the tank. Are they known to fail?

Also do the fuel filters have a non-return valve in them? might that be ticking?

(2011, 1.2Tsi. CBZB)

matthew.bicknell
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Posts: 19
Joined: Thu Mar 01, 2018 1:31 pm
Drives: Polo 6C 2015 SEL 1.2 110
Location: Kent, UK

Re: "Tick" from fuel pump???

Post by matthew.bicknell » Tue Jun 05, 2018 12:01 am

I believe I have heard a similar noise to you. When my car is idling it makes a ticking noise that can be heard when inside or outside the car. It is loudest at the back right side underneath. I have not looked into it yet but have noticed a few things:

1. The noise disappears when the air con is on and idling, have you noticed this?
2. I have not noticed the noise as much after I've fully filled the tank with fuel, have you noticed this?

My noise also disappeared as soon as I increased the revs ever so slightly

I have a 2015 Polo 1.2 TSi.

Matt

wolfie
Silver Member
Posts: 264
Joined: Wed Jul 06, 2011 11:56 am
Drives: 6R0 - 1.2 Tsi SEL
Location: North Staffs

Re: "Tick" from fuel pump???

Post by wolfie » Tue Jun 05, 2018 9:43 am

Cheers Matt.

I had a very brief Google for any information I could find, which actually wasn't very much.

However I came across a couple of things that I need to find some more info on. The lift pump is actually a rotary pump so is unlikely to cause a "tick" as such. If you sit in the car when it's been stood for a while, open the door and turn on the ignition you can hear a little buzz from the pump as it primes. (I think I may have even heard mine prime when simply opening the drivers door) However the pumps on the Tsi engines (and possibly others) have a little PMW (Pulse Width Modulation) control unit that sits just above the tank. While highly unlikely it is possible the pump is being turned on & off rapidly for some reason.

The high pressure pump at the front is pulsatile as it operates directly off the cam and is at very high pressure. It may just be that pressure pulses are travelling back down the fuel lines.

I think that fuel filter also contains a-non return pressure valve. Apparently on Golf 2.0 Tsi engines there are a couple of variants that have different pressure settings. My thoughts are that it as appears noisiest at the filter itself, it may just be the non return valve "ticking" open and closed as it sees the pressure pulses form the high pressure pump end.

I think the cheapest and easiest thing for me to try would be simply swapping the fuel filter. Mine was actually swapped at the last service and I think they used a MANN filter as opposed to a genuine Vdud. (I use an Indie now) I think they are around £30 a pop, so as the price of bits WV bits go, not a fortune. Sods law is I filled up at the weekend so I'll have to do some miles to drain the tank down a little. (though I think they are set up in such a way that it doesn't matter how much fuel is in the tank.)

1. The noise disappears when the air con is on and idling, have you noticed this? (Short answer is I don't know, I rarely run my aircon. I like the windows open.. LOL)
2. I have not noticed the noise as much after I've fully filled the tank with fuel, have you noticed this? (I think it may be the other way round on mine as I've only noticed it since filling up. Though I don't really know)

My noise also disappeared as soon as I increased the revs ever so slightly ( Mine is the same, even a tiny increase in revs and the noise stops completely)


I have my suspicions that VW would label it as a "trait of the car" and it's simply luck that I've not heard it up to now.


Thanks for the reply.

matthew.bicknell
New
Posts: 19
Joined: Thu Mar 01, 2018 1:31 pm
Drives: Polo 6C 2015 SEL 1.2 110
Location: Kent, UK

Re: "Tick" from fuel pump???

Post by matthew.bicknell » Thu Jun 14, 2018 11:31 pm

Did you have any luck finding out what it was?

Mine is still making the noise, going to call the dealer and see if they can have a look at it. It sounds like its coming from the fuel filter area on my car just like yours.

Here's a link to my onedrive where I have a video of the noise: https://1drv.ms/f/s!AkMrqw9ifexFnDNgHv7snELkfvlJ
Is that the same as your noise?

Cheers

Matt

wolfie
Silver Member
Posts: 264
Joined: Wed Jul 06, 2011 11:56 am
Drives: 6R0 - 1.2 Tsi SEL
Location: North Staffs

Re: "Tick" from fuel pump???

Post by wolfie » Fri Jun 15, 2018 9:05 am

Thanks for that Mathew.

I've not pursued it any further as yet. Aside from the appearently new "tick" it seems to be running OK. I'll try and get a similar video of mine over the weekend for comparison. I was of the oppinion that on mine the noise was loudest at the fuel filter itself, but it does sound very much like that. That said I didn't get quite as fat under the car as you managed.

Mine is due for service in the not too distant future, so I was going to ask them to have a listen and see what they think. My first thought was to simply replace the fuel filter first as it's easiest and cheapest. ( I priced them up, they are a shade under £30) However I checked my last service and it's marked as being changed and actually still looks like new under the car. (I know it doesn't mean that it can't be faulty.)
A neighbour has a set of ramps so I'll see if I can borrow them and have a better look.


As a by the by, I checked the screw that tightens the plastic bracket that holds the filter in place, and found it to be very rusty. I happened to have some stainless steel self tapping screws of the same size so replaced it while I was poking about.

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