What Are BMW Swirl Flaps? 

Swirl flaps live in the manifold of BMW diesel M47TU & M57TU engines, and there are either 4 or 6 flaps depending on a number of cylinders. Designed to create a swirl in the manifold and improve combustion under light loads, swirl flaps maximise efficiency and power output. 

Swirl Flap Failure 

Unfortunately, these swirl flaps are poorly designed and prone to failure, leading to costly repairs for BMW owners, and in some case vehicles written off. 
When a swirl flap fails debris can drop down into the engine and when this happens one of two catastrophic failures occur. The debris may stick in the valve port and jam it open, which leads the piston to collide with the valve. Alternatively, the debris can fall into the cylinder leading to damage to the valves and piston itself. 
Another issue our expert technicians encounter with BMW swirl flaps is the screws holding the flap coming loose and entering the combustion chamber, which can cause significant damage. If these screws manage to make their way out of the engine, they can then damage the turbo and CAT when they pass through. 
With more than 50 years combined BMW experience at professional dealerships, the senior diagnostic technicians at Beverley Motor Works can repair and replace BMW swirl flaps to ensure your vehicle maintains at optimum performance. Our expert technicians have decades of experience of diagnosing and servicing BMWs based on their service lights. 

Contact Us 

If you're in need of expert BMW services, 
look no further than Beverley Motor Works. 
Our team is passionate about BMW vehicles, and we strive to provide the best care possible. Contact us today to schedule an appointment or to learn more about how we can assist you with your BMW needs. Trust your BMW to the experts! 
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