Sonic thud/low boom ??

[way up North]

Hi Folks,
I have a Tdi and have been party to some weird noises of late....They begin when the engine is warmed up and are very low bass frequency thumping noises from the deep. These noises have been happening for a few weeks, I have no loss of power, or other issues. The noises are sporadic but they can happen several times in the space of a few minutes, also only when actually accelerating. I have a suspicion the air system is the cause. The noises are very deep and sonic....
Any sensible suggestions/remedies welcome!

Cheers

[Naz2k5]

I think you have Guile from streetfighter under your hood? lol :p

[spike]

Hi way up north
The noise could be caused by the EGR valve. See link for more info
http://www.a2oc.net/forum/showthread.php?t=3871&highlight=mooing

Cheers Spike

[birdsd01]

If it is coming from the passenger footwell, then it is the EGR valve sticking. It happened on my TDi and was fixed under the Audi used car warranty. It happens when the car is warm and you just press the accelerator, I heard it most when crawling through traffic.

Cheers,
Dave

[tdiman]

Check your inlet pipework connections, any slight leak will give these type of noises on acceleration
Cheers Mike