A critical control valve in turbocharged engines that diverts exhaust gas away from the turbine wheel. By regulating how much exhaust drives the turbine, it dictates the maximum boost pressure delivered to the intake manifold. If this valve sticks closed, the turbo will overspeed and create massive boost spikes, often destroying the engine internals through severe detonation.
The customer is complaining about low power, so check if the wastegate actuator is stuck open.
A rattling sound from the turbo area on deceleration is a classic sign of a loose wastegate flapper valve.
Related terms
Boost
The positive air pressure created in the intake manifold by a forced induction system.
Blow-by
Combustion gases that escape past the piston rings and enter the engine crankcase.
Supercharger
A mechanically driven air compressor that forces extra air into an engine.
Detonation
An uncontrolled secondary explosion in the combustion chamber that causes severe engine damage.