Mystery noise from under the hood

[Sunny43.5]

Thanks Stevan it was my first thought .

[stumelb]

When I first read this post , I seemed to think it was similar to a noise that mine makes , like a some kind of vibration . I did find that the plastic air scoops under the bonnet do that at times , especially when idling .They arent fixed they mash together with the intake for the air cleaner and the fresh air intake , but just being plastic they vibrate .I maybe completeley wrong as some say its like an electric antenna winding down, could be the injector pump priming thru to avoid vapour locks to keep fuel in the lines and not air bubbles

[Wardy]

Groaning noise

I have a very low km (25,000) 2012 Comfortline Multivan TD 1340. The vehicle runs well, no engine faults showing and no change in fuel consumption.

For the past couple of weeks there has been what I can only term as a 'groaning' noise from under the bonnet when I turn off the ignition. This is the only time this happens.

Has anybody else experienced this and if so what did it turn out to be? I would also be good to know if it was an expensive 'fix'.

Mike Ward

[JustCruisn]

EGR valve.
Some say it sounds like a cow.
Was a thread last week about it.

http://www.vwwatercooled.com/forums/f136/mystery-noise-under-hood-96984-8.html

[stevan]

Pressure converter

[Sunny43.5]

Had to laugh today while researching the N75 valve on one site they describe it as the "Moo "valve a good sense of humour there . About to order one from OS not paying the local thieves the money they quote .

[LogicprObe]

That is low kms!
I'm up to 280k.

[REVHE4D]

That is low kms!
I'm up to 280k.

I had my n75 i think it was called replaced and my van had done less than 25000km. This would be your issue

Sent from my SM-G930F using Tapatalk

[REVHE4D]

That is low kms!
I'm up to 280k.

280km wow hows is your dpf holding up? Im on 135k

Sent from my SM-G930F using Tapatalk

[Markee]

There are modified vacuum hoses with pulsation damper offered as a 'production change' from VW. They are $200 each plus fitting. I am going to try this before changing out the N75 "Moo Valve" as stated everywhere else online.
The newer design hoses are a 'VW upgraded part' from VW's Technical Product Information sheet 2027520/13
I'm looking to buy the set from the UK as they are half the price. See my other thread about OEM parts suppliers from overseas.

[Markee]

Had to laugh today while researching the N75 valve on one site they describe it as the "Moo "valve a good sense of humour there . About to order one from OS not paying the local thieves the money they quote .

Hey Sunny where about's are you ordering your parts from?

[Rebuild]

removed the mounting bracket,removed hoses and sprayed WD40 into all openings on each of three valves i could see.
Will see if it returns.

[Silver Caravelle]

Mine has been noisey for a number of years (2008 Multi). I recently asked the dealer servicing it whether the N75 should be changed, They said unless it is triggering a fault code and not working, not need to change. I suppose the moo noise is an 'undocumented feature' on VW/Audi vehicles. I gave mine a clean a while back, there was no change, still the moo noise but functioning fine when tested on the 12 v battery.

Regards,

Scott

[REVHE4D]

Mine was flucuating ever so mildy under throttle, you could feel it under slow driving in a carpark in first gear, this annoyed me. Since I had mine changed 5 years ago it has never come back.

Sent from my SM-G930F using Tapatalk

[greymad]

Please refer back to post #53 - and save your money on an unnecessary N75 valve replacement.
Merry Xmas/Happy New Year to all.