Low frequency grunt sound very random on Audi 1.4TDI SE

Crazylegs

Member
Anyone have an idea what this could be, its random and does it at standstill aswell as moving
doesn't seem to be any problem with the running of the car or performance wise, me and my brother are both a bit stumped on this one, it seems to be coming from the front of the car passenger side and is completely random in its nature, there is no set pattern to it!
 
Anyone have an idea what this could be, its random and does it at standstill aswell as moving
doesn't seem to be any problem with the running of the car or performance wise, me and my brother are both a bit stumped on this one, it seems to be coming from the front of the car passenger side and is completely random in its nature, there is no set pattern to it!

Is it a brief or prolonged sound? Does it mostly happen when cold/hot?
 
Could it be described as a soft moo sound?
Could be the EGR valve assembly vibrating
 
If it has warn rubber bushes on the EGR valve you'll hear the noise as you press the accelerator (while in neutral). Try taking the bonnet off to see if the sound is accentuated?
 
I'm wondering if this is the same problem I am having, when I quickly blip the accelerator I get a low pitched quick rumble and also hear this randomly when driving, are there any other tests? if its worn rubber bushes on the egr valve, can these be replaced? Thanks Simon
 
I have an odd noise from the passenger side occasionally. Like a speaker vibrating almost. Wonder if that's the same issue.
 
I also occasionally hear a noise coming from the passenger side. It's a sort of mindless wittering that I usually allow to pass from one ear to the other....

Andy B

Ha.

I'm lucky, I've trained my body to filter out feminine frequencies ENTIRELY.
 
If it sounds like a sub woofer "oof" from the passenger footwell area when you touch the throttle then it is the egr valve sticking. Mine was fixed under warranty a few years ago. It isnt cheap.

sorry

David
 
The odd noise I was having turns out is only there when the stereo is on, and loud. So I'm guessing a speaker is causing something to reverberate.
 
I also have this noise.
It sounds like a muted whoom and lasts for about 1/4 to 1/2 second.
Happens randomly.
At first i thought it was suspension, but then noticed it when pulling away and at standstill when just about to pull away.
Went to an independant Audi/VW specialist who was very helpful.
I gave me some 'proper' injector cleaner and advised on a few noises i have. Told me to add it and thrash the car a bit to clear the built up gunk in the injectors causing my black smoke. Must admit though, didn't enjoy thrashing it at 4000 rpm in 3rd doing 60mph!!
This particular one is one he's heard of a fair bit.
It is a valve which is tucked under the cowling at the back of the engine bay and it is just noisy. Didn't say which one it was though, but as it was an initial visit, I couldn't expect too much for free.
Apparently A3's and A4's have it as well but as they are mounted slightly different they don't make as much noise.
 
That would be the EGR valve---most TDI owners have had a remap and if mapped by stealth racing the EGR valve is mapped out of operation. Yet another reason to get it mapped. cheers mike
 
Would this be it?
I typed in EGR in the search box and this came up.
http://www.eurocarparts.com/ecp/c/A...8399fa54c5324c382e37fe4fe0bf14031bbc47&000525

That's known as the N75 valve which controls the vacuum signal that actuates the EGR valve. Historically the 'mooing' noise has been associated with the mounting of the N75 and the fix was to use rubber bobbins to isolate vibrations resonating through the bulkhead - http://www.a2oc.net/forum/showthread.php?t=5783&highlight=mooing

Cheers Spike
 
All very interesting reading. My noise may be the speaker, it may be the EGR it may even be both or neither. As long as the car goes, and stops I'm going to live with it and classify it as a 'characteristic'.
 
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