The cause: The original plastic Disa valve components wear and often snap causing the symptoms noted above. The pin retaining the flap can also pop out entering the engine! The likely cause of the faults noted above and most common cause is the weak plastic components within the DISA valve unit vibrating together and wearing causing the flap to operate at the wrong times and eventually leading to destruction of the flap plate. The pieces of this flap can even enter the engine often causing severe engine damage; likewise the metal pin that holds the flap plate in position can vibrate loose and enter the engine. The solution: Fit our improved design billet aluminium flap kit, designed to never fail, save the cost of a replacement DISA valve which will only fail again. Using our kit, the weak components of the DISA valve flap and crank lever are replaced with our many times stronger billet aluminium parts, retained by our precision machined screw, which tightly holds the two components together; eliminating wear and the need for the retaining pin which can enter the engine. Our part is completely redesigned to never fail- OEM clearances are reduced minimising vibrations in the part, preventing any future failure. Our kit also includes a high temperature Viton 75 O-ring to create a good seal between the DISA unit and the manifold, eliminating any air leaks. Vehicles Affected : BMW M54 3.0 & Liter Engine Applications E36 1999-2002 Z3 3.0i Coupé E36 1999-2002 Z3 3.0i Roadster E39 2000-2003 530i Sedan E39 2000-2003 530i Touring E46 1999-2006 330Ci Convertible E46 1999-2006 330Ci Coupé E46 1999-2005 330i Sedan E46 1999-2005 330i Touring E46 1999-2004 330xi Sedan E46 1999-2005 330xi Touring E53 1999-2006 X5 3.0i SUV E60 2002-2005 530i Sedan E65 2002-2005 730i Sedan E66 2002-2004 730Li Sedan E83 2003-2006 X3 3.0i SUV E85 2002-2005 Z4 3.0i Roadster BMW Part# 11617544805 or 11617502275 Number Stamped on DISA Housing: 7544805 or 7502275