I'm hearing tapping noise from the engine when I decell...."engine break" my m6...it'll do it stopped also when I rev it up...only in the lower rpms...and goes away as it increase....not sure if it has to do with a recent oil change I did this afternoon...I used german castrol 0w30. which is what I used on the previous oil change...so the motor has seen the stuff before...performance doesn't seem to be affected...but I never heard this noise the last time... anyone have any ideas what this might be?

 

I'd try switching to a 5W30 at least. Personally I run Mobil 1 10W30 synthetic in mine.

 

does it do it at idle? could have some valve train noise.

 

Did you also change the filter? Which one? I would suspect a faulty filter before that oil. I am using that oil in six cars and it has produced fantastic results to date. As for switching to the Mobil-1, the Castrol has more viscosity so I would leave it in. Might want to throw on a new filter.