slk350 tapping from engine

[north007]

Hi to you all I need some advice regarding my slk350 on a 56 plate.
With 7000 miles on the clock, it has started to make a tapping noise
On the drivers side of the engine but not all the time when you rev the engine and let it idle it goes away for about 2 to 3 minuets and then returns.
I think its one of the hydraulic tappets not staying full is this normal and if not should this be fixed under the warranty, but it dose not do it all the time its just had a service at a MB dealer but not where I live now any advice welcome thanks

 

[st4]

Is it knocking or something more serious. Try using higher octane fuel in case you put cheap super market fuel in and the car doesn't like this

Its a 56 plate so still under warranty so if it continues take it back. There may be error codes that can be read to ascertain the problem.