Powertrain
generic / SAE
P25B3
Turbocharger/Supercharger Wastegate A Stuck Open
Wastegate A is mechanically stuck open. Exhaust gas bypasses the turbine even at low load — turbo cannot reach target speed, boost is permanently low and the engine feels asthmatic. Common causes are seized linkage, broken return spring or carbon-locked wastegate flap.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / B3
Possible causes
- Seized wastegate linkage high
- Broken return spring medium
- Carbon or debris buildup preventing free movement low
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 400–2500 €
- Estimated time: 1.5–6 h
- Component: wastegate a
- Component: turbocharger a
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012