T25 Intake manifold pressure relief vlave 068-129-633
The pressure relief valve is an emergency device in case the relief valve (a relief valve is a valve located in the exhaust of a turbocharged engine. this valve acts as a bridge to the turbocharger, preventing it from building up too much pressure as the engine revs up or is subjected to higher loads) of the turbocharger can no longer do its job. When the relief valve is rejected, the turbo overpressure can no longer escape, and this overpressure control valve takes over.
This valve is often removed to increase turbo pressure, which is not a good idea, as you run the risk that, should the relief valve fail, there will be no back-up and the damage will be greater than a simple broken relief valve.
If the pressure relief valve is no longer present, or due to continuous overheating caused by temperature differences, the plastic becomes brittle, you will need to install or replace a new one.
