West Seattle Auto Repair

West Seattle Auto Repair

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How Walnut Shells Can Help Your Mini or BMW's Performance

BMW and Mini Cooper (along with other vehicles) with GDI engines are both cars that can experience carbon build up over time causing drivability issues. 


Gasoline Direct Injection (GDI) is a method that automakers have used to inject gasoline at a high pressure directly into an engine’s combustion chamber rather than into the intake tract or cylinder port.  Fuel is better measured than older fuel injection or carbureted systems - making the vehicle more fuel efficient.  The problem that can result is that the fuel’s detergents can no longer keep the intake’s clean so carbon and dirt can start caking and building up on the walls.  As the buildup thickens, the vehicle’s performance can suffer.  The check engine light may come on and the car can hesitate or stall. 

 If carbon has built up to a point where the vehicle’s performance has been affected, we have had success with a service called a walnut shell blast.  Walnut shells are gentle enough to clean and sweep away the carbon without damaging the valves.  Once walnut shell blasting has been done, treatments can be added to routine maintenance services to try and keep carbon build up at bay.  


Walnut shells after carbon blast                           Walnut shells before carbon blast 


If your car is starting to have issues with stalling, hesitation, performance or check engine light with codes PO300,301,302 you may be experiencing carbon build up.  Call or schedule a diagnostic with us at 206 938 8685 or at www.swedishauto.com/appointments   



Mini Cooper
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