VW Fox Charge Sensor Issues Causing Power Loss & Noise

Based on my experience with a 2009 VW Polo diesel, I encountered nearly identical issues last year. As someone with moderate car repair experience, I initially thought it might be more serious, but it turned out to be exactly what you suspect. The symptoms match perfectly, the engine light, reduced power, and that characteristic whistling noise during acceleration. The air temperature sensor and its connection were indeed the culprits. My airflow sensor readings were also erratic, which the diagnostic computer picked up. The repair was straightforward, the workshop found a damaged wire and connector at the air intake sensor assembly. They replaced the entire air temperature sensor unit and fixed the connection. Total cost was 95€, which included diagnostic time and parts. Before doing any repairs, could you share: Current mileage on your Fox, When was the last engine service, Are there any other warning lights besides the check engine light, Does the whistling noise change with engine temperature The air sensor issues often start subtly with occasional power dips before developing into the full set of symptoms you described. Getting it fixed promptly helps prevent any potential damage to other engine sensors or the air intake system.

Thanks for sharing those details. Just had my service done at 70084km last month. After reading your response, I checked again and noticed the whistling sound does get louder when the engine is warm. The engine temperature gauge also fluctuates slightly during acceleration. No other warning lights besides the check engine light at this point. The automotive sensor diagnostic data matches what you described with your Polo. Good to know the charge sensor replacement fixed those exact symptoms. That 95€ repair cost seems reasonable considering the alternative of potential engine damage from running with a faulty air temperature sensor. Will get it checked this week. The symptoms line up too perfectly to ignore, especially given our similar engine setups.

Those temperature gauge fluctuations during acceleration definitely support the diagnosis of a faulty charge air temperature sensor. On my Polo, I also noticed those subtle gauge movements before the full symptoms developed. The fact your service was recent actually helps narrow things down, as many other potential causes would have been caught then. The connection between the airflow sensor and temperature fluctuation is quite typical for this specific issue. Since our engines are so similar, I suspect you will find the same damaged wiring or connector issue I had. The repair shop might want to check the entire sensor assembly while they are at it, in my case, they found some buildup around the air sensor that was contributing to the erratic readings. Just monitor those temperature fluctuations until you get it in. If they become more pronounced or you notice any changes in the whistling noise pattern, consider bringing it in sooner rather than later. The sensor replacement itself is quite quick once they have the parts on hand.

Your VW diagnosis makes a lot of sense. With my mileage at 70084km and recent service, the air temperature sensor issue seems the most likely culprit. The engine temperature fluctuations during acceleration that I noticed match exactly what you experienced with your Polo. The similar whistling noise patterns and diagnostic codes between our vehicles is quite convincing. Temperature sensor problems typically show these exact symptoms, the check engine light, power loss, and those distinct sounds from the air intake system. The 95€ repair estimate feels reasonable, especially considering how a faulty temperature sensor could lead to more serious engine issues if left unchecked. Will schedule the repair this week since all signs point to this being the same sensor problem you encountered. I appreciate you mentioning the possible wiring and connector issues they found on yours. Will have them check the entire air sensor assembly for any buildup or damage while they are replacing the parts. Better to address everything related to the air intake system at once than risk ongoing temperature fluctuations or sensor problems.