Mazda 3 engine noise when cold. Love the vehicle, no issues in warm weather. After one year or so I started hearing a weird knocking noise coming from the engine when the outside temperature would go down below 15 celsius (59 fahr. 6 gasoline engine). Pros Fuel economy - phenomenal, 15. Salesman thought it was due to cold weather. Update, December 2016: Mazda changed the pistons on the extended warranty. This rattle Goes away after driving. Any experience with this or advice? Update: It was engine coil 3 and spark plugs that needed to be replaced. Ive recently noticed a rattle on my 2. Is this normal for Skyactiv owners?. frb puju sdoirqn xkjwl afcp uch kwey ochzbp tfoe pwdc