Audi Q7 TDI Power Loss: Charge Sensor Warning Signs

I dealt with almost identical issues on my Audi Q5 3.0 TDI from 2009. The symptoms matched exactly what you describe, reduced power, strange noises, and engine warning light related to the air temperature sensor readings. After some basic troubleshooting, my workshop found that the air sensor connector had developed a poor connection due to vibration and engine heat. The engine sensor wiring had some wear, causing inconsistent temperature gauge readings. The fix was relatively straightforward, they replaced the damaged wiring and connector to the charge air temperature sensor, which cost 95 Euro including labor. This resolved all the symptoms completely. Before jumping to conclusions though, could you share: Any diagnostic codes stored in the system? Does the problem get worse when the engine is hot? Have you noticed any changes in fuel consumption? Are there any other warning lights besides the check engine light? These details would help determine if your issue is identical to what I experienced. While the air temperature sensor connection was the culprit in my case, similar symptoms can sometimes point to other components in the intake system. Based on my experience with similar diesel engines, I would recommend having a professional check the entire intake system and all related automotive sensors before replacing parts.

Thanks for sharing the details. After the latest service at 9844 KM, my workshop ran diagnostics and found the airflow sensor was also showing erratic readings alongside the charge sensor issues. The fuel consumption has increased by about 15% and the problem definitely worsens with a hot engine. No other warning lights appear besides the check engine light. Error codes point to both the air temperature and charge sensor circuits. Your wiring issue suggestion makes sense, I noticed the symptoms started after some recent engine work. Will have the intake system connections checked before replacing the entire sensor unit.

Based on those additional details and comparing to my Q5 experience, this definitely sounds like a related but slightly more complex issue than what I encountered. The combination of erratic airflow sensor readings alongside the charge sensor problems suggests the wiring harness might be damaged in multiple spots. The 15% increase in fuel consumption and heat-sensitive behavior matches what I experienced before fixing the sensor connections. In my case, the poor connections were causing the engine management system to run rich as a safety measure. Given your symptoms started after engine work, check if any intake system components were disturbed during that service. Sometimes even slight misalignment of air intake components can stress the wiring harness and sensor connections. When my workshop did the final fix, they actually found minor damage to several sensor connectors in the intake area. The automotive sensor wiring bundle had rubbed against a bracket, affecting multiple connections. The complete repair included: Inspecting all temperature gauge and sensor wiring in the intake area, Replacing damaged sections of the wiring harness, Securing loose connectors, Testing all airflow sensor readings after repair The total repair cost was 180 Euro, higher than just fixing a single connection, but it prevented future issues. Suggest having your workshop perform a complete intake system inspection focusing on all sensor connections rather than just replacing components.

I checked with my workshop yesterday and you were absolutely right. The technician found multiple damaged spots in the wiring harness where it runs near the intake manifold. The charge sensor connector was loose and showed signs of heat damage, while the engine sensor wiring had worn through in two places. They completed the full repair just like you described: Replaced the damaged wiring sections, Fixed all loose connections, Tested temperature sensor readings, Verified charge sensor operation Total cost was 195 Euro but worth every cent. The engine runs perfectly now, no more power loss or strange noises. The temperature gauge readings are stable and the check engine light has stayed off. Really appreciate the detailed advice about checking the entire intake system rather than just replacing parts. This saved me from unnecessarily replacing sensors when the wiring was the real problem.