Anyone know what this sound could be?

[justin13703]

I have a 2014 TDI Passat, 45k miles. I’ve noticed a clicking sound coming from under the hood, only from about 1200rpms up. It doesn’t make the noise at idle, and it doesn’t start until a few minutes after startup. There are no driveability issues, no check engine light, and no codes in vcds. It can’t be heard from the interior of the car. I don’t believe the sound is coming from the motor, I’m thinking something related to the belt drive or a solenoid of some kind? The sound definitely seems to be coming from the passenger side of the engine bay.

Here is a video of the sound, the phone was in the engine bay at the time and it makes the clicking seem much louder but it is very easy to hear in the video.

- YouTube

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[NSTDI]

I use an automotive stethoscope for finding source of noise, the long metal tip touching things usually finds or eliminates things.

 

[justin13703]

I use an automotive stethoscope for finding source of noise, the long metal tip touching things usually finds or eliminates things.

Yeah I tried to use one of those. But the sound seems to be hard to pinpoint. I may pull the serp belt off this weekend to rule any of that out.

 

[justin13703]

Well I found out what it is for anyone in the future with this symptom. It is the fuel metering valve on top of the HPFP. The problem is finding one because it usually isn’t sold by itself.

 

[NSTDI]

It would be covered on the emissions warranty if you can convince the dealer to replace it? Tell them you are afraid the HPFP will blow up.

 

[justin13703]

Yeah I’m sure it is under warranty because I’m still within my two year bumper to bumper as well. The thing is the dealer will replace the whole hpfp which sounds like a good deal but every time I’ve taken it to the dealer for work something has been screwed up when I got it back. And replacing the hpfp is relatively involved because of being driven by the timing belt.

I did find one of the oem metering valves online but it involved a lot of cross referencing. Had to find the Bosch part number instead of the vw part number. It was only 100 bucks and my warranty deductible is 50 anyway. So I’ll give it a shot.

 

[740GLE]

let us know if the sound still persists and if you see any metal when you pull that valve. Quite frankly with how sensitive the fueling system is to throwing codes, I'd say its normal until a code pops up.

 

[justin13703]

let us know if the sound still persists and if you see any metal when you pull that valve. Quite frankly with how sensitive the fueling system is to throwing codes, I'd say its normal until a code pops up.

I pulled it the other day to get some good pics of it to help with matching up a new one and to see if I saw anything obvious. It was crystal clear in there, no metal flakes or debris of any kind. I’m sure since there are no codes, it is still functioning correctly, just a bit noisy for some reason. It should be here Thursday so I will post back as soon as I get it installed with the results.

 

[justin13703]

Well somehow it didn’t fix the noise. It must be internal to the pump somehow involving that metering valve because it does go away when it’s unplugged.

It was worth a shot, I guess I’ll take it in and see what they say. It is still under the b2b and emissions warranty so it shouldn’t be an issue, just didn’t want them to have to tear it apart.

 

[740GLE]

what you actually maybe hearing is the metering valve working, when its unplugs it's in fail safe mode.

 

[justin13703]

It’s real loud. Like sounds like my engine is about to self destruct from a hellacious valve tap lol. A friend of mine and my cousin both have 2014 Passat TDIs and theirs dont make any kind of tap like this.

 

[740GLE]

Can you test the in tank lift pump?

 

[justin13703]

Can you test the in tank lift pump?

I’m sure I could cycle it on and off with the vagcom. But the noise definitely isn’t coming from the tank. I’d imagine if something was wrong with the lift pump anyway it would have a pressure issue.

 

[740GLE]

Well if the lift pump is weak, it might be forcing the HPFP outside its normal limits causing the metering valve to hammer, not sure, just a wild guess.

This EA288 design only has one lift pump, where previous gens had two lift pumps (one out back one under the hood) to reach 60PSI or something, i forget the exact value.

 

[justin13703]

Well if the lift pump is weak, it might be forcing the HPFP outside its normal limits causing the metering valve to hammer, not sure, just a wild guess.

This EA288 design only has one lift pump, where previous gens had two lift pumps (one out back one under the hood) to reach 60PSI or something, i forget the exact value.

I guess it’s possible. Either way the dealership is looking at it Saturday because I needed to get one of my free oil changes done anyway. So I’m curious to see what they say. The advisor that came and listened to it agreed that it definitely isn’t normal, so I’m hopeful they’ll try to hunt it down.