Tiguan TDI Boost Issues Point to Failed Sensor

Had the exact same symptoms on a 2014 VW Golf TDI. The check engine light kept triggering and the turbo system was clearly not performing right. After diagnosing multiple boost leak points, we found the main issue was a faulty boost pressure sensor connection. The whistling sound during acceleration is a classic sign of a boost leak in the turbo system. In my case, the air intake hose had a small crack, and the boost sensor plug was corroded. The stalling at idle is particularly concerning as it indicates the engine management system is getting incorrect readings. The fix required cleaning the sensor connections, replacing the corroded plug, and installing a new air intake hose. While not a major repair, leaving it unfixed can cause long-term damage to the turbo system and further decrease fuel efficiency. Worth checking all boost-related connections and hoses before replacing parts. Sometimes the issue is as simple as a loose clamp or damaged seal rather than a failed sensor. A proper boost leak test should identify the exact problem point.

Thanks for sharing your experience with the Golf TDI. My case sounds very similar to yours. The issue with my Tiguan is still ongoing and the engine light started flashing again today. The boost pressure sensor definitely seems like a prime suspect, especially with the turbo system acting up. Would you remember roughly how much you paid for the repairs? Also, has everything been working fine since the fix or have you noticed any other related problems with the intake manifold or boost system?

Finally took my Tiguan to a certified shop last week and they confirmed the boost pressure sensor was the culprit. The total repair cost was 95€, which covered fixing a defective cable connection to the sensor. Since the repair, the turbo system has been performing perfectly, no more engine light, whistling sounds, or power issues. The technician mentioned the intake manifold and other turbocharger components were all in good condition. The stalling and poor fuel economy were definitely caused by the faulty sensor connection throwing off the engine management readings. Looking back, should have addressed this sooner. Running with incorrect boost sensor readings can put extra stress on the entire turbo system. But for 3 months now, everything has been working exactly as it should, proper boost response, stable idle, and fuel economy back to normal.

After dealing with ongoing boost issues with my Tiguan, I finally got it properly diagnosed and fixed. The turbocharger problems were exactly as you described, caused by a faulty boost pressure sensor connection. The check engine light kept coming on because the system was getting incorrect readings. Took it to a new certified shop last week after my disappointing experience with the previous mechanic. They did a thorough check of the air intake system and quickly found the actual problem. Total repair was 180€ which included cleaning the connections and replacing the damaged sensor wiring. Since the fix, the engine runs perfectly, no more whistling sounds or power issues. Fuel economy is back to normal and the idle is stable. The mechanic showed me how the corroded wiring was causing the turbo boost system to malfunction. Really glad I got a second opinion instead of replacing parts unnecessarily. The turbocharger and other components were actually fine, it was just the sensor connection causing all the trouble.