VW Lupo Turbo Boost Sensor Causing Power & Stall Issues

As a VW Golf TDI 2004 owner, I experienced nearly identical symptoms. The whistling noise combined with power loss strongly points to boost-related issues. The check engine light came on intermittently in my case. First, have the pressure sensor tested, its often the root cause when experiencing these specific symptoms. In my case, the pressure sensor connector had corroded, creating inconsistent readings that confused the engine management system. The air intake hose also showed small cracks, causing a boost leak that explained the hissing sound. The repair involved: Cleaning and reseating the pressure sensor connections, Replacing the cracked intake hose, Performing a full diagnostic scan, Testing the turbo system for proper operation This was not a major repair but required proper diagnosis to avoid replacing parts unnecessarily. The symptoms you describe match a classic boost leak or faulty pressure sensor scenario. Getting it fixed promptly prevents potential turbo damage and continued poor fuel economy. The engine light and reduced power are key indicators that the ECU is receiving incorrect boost pressure readings. Have a professional check both the sensor connections and complete turbo system for leaks before replacing components.

Thanks for sharing your experience, those symptoms match what happened to my Lupo back in 2019. After the diagnosis showed similar boost leak and pressure sensor issues, replacing those parts fixed the whistling and restored normal power. The engine light also stopped appearing out of nowhere. Just wondering, do you remember roughly what the total repair cost was for your Golf? And has everything worked properly since the fix, or did you notice any other turbo system problems pop up later?

Thanks for asking about the repair costs. After seeing the mechanic, my VW Golf issue was indeed just a bad boost pressure sensor, specifically a faulty cable connection that was causing incorrect readings in the turbo system. The total repair came to 95€, which included testing the entire intake manifold and ensuring proper pressure sensor operation. The repair has held up perfectly since then with no additional turbo system problems. The air intake and boost performance returned to normal, and fuel consumption went back to standard levels. The unusual engine light never came back, and the whistling noise completely disappeared. The relatively low repair cost was because the mechanic found the actual issue, a simple connector problem, rather than unnecessarily replacing the entire pressure sensor or other turbo components. This kind of precise diagnosis really saves money compared to the parts-swapping approach some shops take.

Got my Lupo back from the shop yesterday. Turned out the air intake had a small crack and the boost sensor connector was loose, similar to what you described. The mechanic did a full pressure test of the turbo system and cleaned all connections before replacing the damaged parts. Total bill came to 150€ which included new pressure sensor wiring and intake hose plus labor. Much better than the 400€ quote I got from another shop that wanted to replace the entire boost sensor assembly. Car runs perfectly now, no more whistling or jerking during acceleration. Fuel consumption is back to normal and the turbo boost feels strong again. Really glad I asked here first instead of rushing into expensive repairs. Will definitely keep an eye on those intake connections during future maintenance.