VW Up Engine Light: Bad Temp Sensor Causing Sluggishness

Had the same symptoms on a 2013 VW Polo TSI. The charge sensor issue created similar performance problems, sluggish acceleration and whistling sounds from the engine bay. The air temperature sensor malfunction was causing incorrect readings, making the engine management system run rich fuel mixtures. Initial diagnosis showed connection issues between the sensor plug and wiring harness. The fix required cleaning the corroded terminals and replacing the air intake temperature sensor assembly. Some mechanics might suggest replacing just the sensor, but the complete assembly replacement prevents future connection problems. The repair took about 2 hours at the shop. This is a relatively common issue that affects engine performance and fuel economy but does not cause permanent damage if addressed promptly. The temperature sensor plays a crucial role in the air intake system, and faulty readings can trigger various driveability issues. The whistling noise typically comes from irregular airflow readings causing boost pressure fluctuations. Getting a second opinion was the right move. Make sure the shop tests the sensor connections before replacing parts. A proper fix includes: Testing wiring connections, Cleaning connector terminals, Replacing temperature sensor assembly, Clearing error codes, Test driving to confirm proper operation

Thanks for sharing your experience. My VW Up is showing those exact symptoms and getting the same error codes. Great to hear the air temperature sensor assembly solved it completely. Quick follow up, do you recall roughly how much you paid for the full repair including labor? Also, has the temperature fluctuation problem stayed fixed or have you noticed any other airflow sensor issues since the repair? This helps give me a cost estimate before heading to the shop. Current quotes seem high so trying to confirm if they are reasonable.

Just got around to seeing your follow-up about the repair costs. After having the charge air temperature sensor fixed on my Polo, I can confirm it was a straightforward repair that cost 95€. The mechanic found a faulty cable connection at the sensor plug, which they repaired without needing to replace the entire assembly. The engine sensor has worked flawlessly since the fix six months ago. No more temperature fluctuation warnings or airflow issues. The car runs smoothly with proper acceleration, and the whistling noise completely disappeared. The check engine light hasn't returned either. Based on your description, it sounds like you have the identical issue. A reputable shop should be able to diagnose and repair the air sensor connection without excessive costs. If they quote significantly more than 100€, they might be planning unnecessary replacements. The key is having them properly test the wiring and connections first, rather than automatically replacing the entire temperature gauge unit. Most of these sensor problems stem from connection issues rather than component failure.

Thanks for all the feedback. I ended up getting it fixed last week and wanted to share my experience since others might run into similar problems. Took it to a different shop that specializes in VW repairs. They found corroded wiring near the air intake sensor which was causing the temperature readings to go haywire. Total repair came to 85€ including labor, much better than the 250€ quote from the first place. The mechanic showed me the damaged wiring and explained how the corrosion was affecting the airflow sensor readings. They cleaned the connections, replaced a small section of wire, and reset the engine sensor. The whole repair took about an hour. Car runs perfectly now, no more whistling noise and the sluggish acceleration is gone. The check engine light cleared right after they fixed the wiring. Really glad I got a second opinion instead of replacing parts unnecessarily. Best part is the temperature fluctuation warnings completely stopped. The engine management system gets proper readings from the sensor now. Money well spent considering how much better the car performs.