OEM Diverter Valve & Hose, Rear - E82 135i, E9X 335i N54 (11657556556)
Stock replacement diverter valve and connecting hose to fix annoying boost leaks
The N54 engine in the E82 135i, E90/E92/E93 335i uses a bypass / diverter system to re-route intake air instead of a traditional blow-off valve. This system re-directs charged intake air back into the turbos instead of over-pressurizing the intake. Traditional blow-off valves dump the charged air into the engine bay (atmosphere), which is not emissions friendly. The problem that N54 owners experience is the plastic diverter valve loses its seal and the connections get brittle and the hose cracks. This is called a boost leak as charged air escapes the intake and doesn't make it into the engine. Owners experience a lack of power without as much pressurized air. There are stronger diverter valves and hoses available, and we highly recommend them, but to keep the factory performance and appearance these OEM replacement N54 diverter valves are the way to go.
Also inspect the chargepipe that these are installed to as the factory plastic chargepipes are also known for cracks and leaks, especially at the throttle body connection.
E82 / E88 (08-13) > 135i
E82 / E88 (08-13) > 1M (11-12)
E90 / E91 / E92 / E93 (06-13) > 335i
E90 / E91 / E92 / E93 (06-13) > 335is
E90 / E91 / E92 / E93 (06-13) > 335xi