A4 TDI making crunch/grinding noise

[JuniorD]

Recently got a 2004 A4 2.5 TDI Convertibe, still under warranty with Audi.
The car is fantastic and am having a great time with it despite the attrocious weather.

However I noticed it makes a peculiar noise which sounds strange to me.
After start-up and after moving about one car length (still in first gear)
there comes a single solitary crunch/grind noise from somewhere below the engine.
It can be felt slightly through the accelerator. The noise occurs exclusively after
starting up and never during normal driving or subsequent moving off from stationary.

Any ideas what it may be? All thoughts most welcome!

Thanks,

JD.

[phumy]

JuniorD said:

Recently got a 2004 A4 2.5 TDI Convertibe, still under warranty with Audi.
The car is fantastic and am having a great time with it despite the attrocious weather.

However I noticed it makes a peculiar noise which sounds strange to me.
After start-up and after moving about one car length (still in first gear)
there comes a single solitary crunch/grind noise from somewhere below the engine.
It can be felt slightly through the accelerator. The noise occurs exclusively after
starting up and never during normal driving or subsequent moving off from stationary.

Any ideas what it may be? All thoughts most welcome!

Thanks,

JD.

If its under warranty take it back and get them to fix it.

[Isoproturon1]

Thought all ABS-equipped cars did this, though most are inaudible including the A4s I have had.

[Silverbullet767]

Is it a quattro?

Maybe a slightly ceased driveshaft?

[JuniorD]

Silverbullet767 said:

Is it a quattro?

Maybe a slightly ceased driveshaft?

It's not a quattro and the driveshaft seems fine.

I will be talking it to Audi eventaually however
just like to get the bottom of things before being told
'they're all like that' (hopefully)

[Isoproturon1]

It's the ABS/traction self-test, I tell you !!

But will you listen, no...

[Tame Technician]

Hi I'm an Audi center technician, ITS THE ABS SELF TEST!!!. You are far from the first cumstomer to complain about this, so dont feel silly if you want to take it to audi, but do insist a technician comes with you and show him the noise, he will say ABS self test.

Try resting your foot lightly on the brake pedal next time you move away from startup, I guaranty you will feel the pedal vibrate at the moment of noise.

[phumy]

JuniorD said:

Recently got a 2004 A4 2.5 TDI Convertibe, still under warranty with Audi.
The car is fantastic and am having a great time with it despite the attrocious weather.

However I noticed it makes a peculiar noise which sounds strange to me.
After start-up and after moving about one car length (still in first gear)
there comes a single solitary crunch/grind noise from somewhere below the engine.
It can be felt slightly through the accelerator. The noise occurs exclusively after
starting up and never during normal driving or subsequent moving off from stationary.

Any ideas what it may be? All thoughts most welcome!

Thanks,

JD.

I bet when you take it in, they say, " thats normal sir, didnt you know all A4's do that on start up"

[Isoproturon1]

Tame Technician said:

Hi I'm an Audi center technician, ITS THE ABS SELF TEST!!!. You are far from the first cumstomer to complain about this, so dont feel silly if you want to take it to audi, but do insist a technician comes with you and show him the noise, he will say ABS self test.

Try resting your foot lightly on the brake pedal next time you move away from startup, I guaranty you will feel the pedal vibrate at the moment of noise.

TFFT!!! I bet it even tells you in the manual, did with our old Fiesta.

[JuniorD]

Thanks Isoproturon1, kudos to you and thanks to Tame Technician for the verification!

I'dnever heard (or heard of) an ABS self test before but now I can look forward to a very loud one every morning.

[Isoproturon1]

JuniorD said:

Thanks Isoproturon1, kudos to you and thanks to Tame Technician for the verification!

I'dnever heard (or heard of) an ABS self test before but now I can look forward to a very loud one every morning.

LOL.

In all seriousness, maybe it should be looked at - all 3 of my A4s (B6 model) have been silent when doing this, and they've all been high mileage so there might be something worth checking if you can claim on a warranty.