2009 Mazda6 engine noise

[jkobty]

I am getting a tapping engine sound when accelerating from a stop at low RPM. The sound disappears at higher rpm. It is also more prevalent after the car has been driven for at least 5 minutes (Warmed up). It started happening immediately after my first oil change at the dealer. dealer insists noise is normal, but I compared to a brand new car on the lot, and that car has no noise. If idling you can simulate the sound if you keep the RPM's around 1200.
There is also piston slap sound when first starting the car, but it decreases after the car warms up, but does not completely go away. Best description I can find is the car idles like a diesel. Any ideas?

 

[roger doiron]

I'm getting the same noise. So far they have changed the whole top end of the motor. It is still making the same noise. Mazda Canada is sending a tech man to hear for himself and hope resolve the problem. I will let you know what happens.