Hello, hope someone can shed a bit of light on this for me, I have a Allroad A6 3.0tdi sport quattro with 74000:mile on it, my car make a noise like pinking ,the noise  you get in petrol engines when fuel is wrong for example. I only does it when I accelerate i.e underload not so much in the mornings but only slight, this seems to be the only problem and it doesn't effect the cars performance, and no fault codes, any ideas anyone.

I'd recommend getting a diagnostic check to see if any fault codes flag up 

Hello, hope someone can shed a bit of light on this for me, I have a Allroad A6 3.0tdi sport quattro with 96000:mile on it, my car make a noise like pinking ,the noise  you get in petrol engines when fuel is wrong for example. I only does it when I accelerate i.e underload not so much in the mornings but only slight, this seems to be the only problem and it doesn't effect the cars performance, and no fault codes, any ideas anyone.

David.

I have merged your latest post into an identical one you posted on May 18th last year. Have you even bothered to read the reply from Steve Q?

Have the engine mounts and gearbox mounts been checked? As the movement could cause noise. 

Could it be something to do with liquid sloshing when I get loads and it throwing off the sensors? 

For example when I had an issue with my A6 washer bottle leaking it wouldn't always tell me it was low unless the washer fluid moved away from the sensor if that makes sense.