2.0L ENGINE NOISE WITH COLD COOLANT TEMP

Applicable Models

Customer may experience an engine rattle under light to moderate        
acceleration with engine coolant temps below 149 deg f and engine       
rpm's between 1500 to 2500.                                             
                                                                        
Confirm noise only occurs within the VTCS(Variable Tumble Control       
system) operation "valve closed" period (when ECT is below 149 deg f)   
                                                                        
The noise is a result of the intentional swirl that is generated        
when the VTCS plates are closed. This swirl accelerates the burning     
speed of the air/fuel mixture for efficient combustion and enhanced     
engine performance during cold engine coolant temperatures and low      
engine RPM operation periods.                                           
Although the noise does not have a negative affect on the engine and    
disappears once the engine coolant reaches 149 degrees Fahrenheit.      
Mazda realizes that it is an annoyance to some customers, therefor      
Mazda is investigating new tuning standards in an effort to address     
customer dissatisfaction.                                               
                                                                        
Until the new standard is availible no repair attempts should be made.