A1 Turbo Failure Symptoms: Whistling, Stalling & Jerking

Had similar symptoms on my A3 2014 diesel with 165k km. The turbo system issues started the same way, whistling, hissing, and poor performance. After diagnostics, the boost sensor connection was indeed the culprit. The air intake pressure sensor had a damaged wire harness and corroded plug, causing incorrect readings to the engine management system. The fix required replacing the boost sensor wiring harness and cleaning the connection points. Not a major repair, but crucial for proper turbo boost control and engine performance. The entire job took about 2 hours. Without proper sensor readings, the engine control unit receives incorrect air intake and boost pressure data, leading to: Poor fuel economy, Reduced power, Rough idle, Engine warning lights, Potential turbo system damage if left unfixed Always insist on getting the diagnostic codes read first. A reputable shop will show you the actual error codes before suggesting repairs. The boost sensor and its connections are common failure points in these engines.

Thanks for sharing that experience. I had almost identical issues with my A1 last summer, check engine light, weird boost behavior and all those symptoms. My intake manifold was actually cracked which caused a major boost leak, plus the boost sensor wiring was damaged like in your case. Did you end up paying a reasonable amount for the repair? Just wondering because mine ended up costing more than expected since they found the additional intake manifold damage. Also curious if youve had any other turbo-related problems since getting it fixed?

Thanks for asking about the follow-up. After seeing the mechanic last week, they confirmed the boost pressure sensor was the main problem. The repair was straightforward, just 95 Euro to fix the faulty cable and plug connection. Much cheaper than replacing the entire turbocharger or dealing with major boost leak repairs like your cracked manifold. The engine light hasnt come back since the fix. The turbo system is running smoothly now with proper boost pressure readings. No more whistling or power loss issues that were happening before. Its been about 2000km since the repair with zero turbo-related problems. The pressure sensor repair made a huge difference in performance. The engine response is back to normal and fuel consumption has improved significantly. Looking back, those error codes pointing to the boost sensor connection were spot on. Good thing we caught it before it could cause damage to other turbo components.

Finally got my car back from the shop yesterday. The mechanic found a faulty boost sensor and damaged wiring just like yours. Total bill came to 120 Euro for parts and labor, which wasnt as bad as I feared. They showed me the check engine codes first and explained everything before starting work. The turbo system is working perfectly now, no more weird noises or performance issues. Fuel economy is back to normal and the engine runs smooth at idle. Such a relief it wasnt a major turbo failure like I initially worried about. Got lucky finding an honest mechanic through a local car forum. They specialize in turbo diagnostics and even showed me the old damaged parts. Really helped rebuild my confidence after getting ripped off at my previous shop. Going to stick with them for future repairs.