Boost Sensor Issues Causing Multiple Engine Problems

I had a very similar issue with my A3 diesel (2 years older than your model). With some experience working on turbocharged engines, I recognized these symptoms immediately. The turbo boost issues you describe match my experience exactly, the whistling noise, power loss, and increased fuel consumption were identical. My turbocharger was fine, but the boost sensor was giving false readings due to a damaged wiring connection. The mechanic performed a diagnostic scan which showed erratic boost pressure readings. They tested the intake manifold and turbocharger connections first, but ultimately traced it to a corroded plug connection at the boost sensor. The repair involved cleaning the connector and replacing some damaged wiring, costing 95 Euro in total. Before suggesting more specific solutions, could you share: Your exact model year, Current mileage, Whether the check engine light shows any specific error codes, How long these symptoms have been occurring This information would help determine if your issue is similar to what I experienced with the pressure sensor wiring, or if it might be related to other components in the turbo system.

Thanks for the input, wanted to provide those extra details as requested. This is a 2000 Audi A2 with 180915 KM on the odometer. The issue started about 2 weeks ago. I hooked up an OBD scanner yesterday and got error code P0236, which apparently relates to the turbocharger boost sensor circuit. Checked the sensor connector and found some oil residue around it, which might indicate a leak in the air intake system. Based on your experience with the sensor wiring, I will have my mechanic thoroughly inspect the boost sensor connections. However, the oil residue makes me think there could also be a boost leak somewhere in the intake manifold that needs addressing.

Thanks for those additional details. The oil residue you found near the sensor connector is particularly telling. While my A3 issue was purely electrical, your situation sounds more complex with potential mechanical concerns in the turbo system. The P0236 code matches what I experienced, but the oil residue suggests you might be dealing with both a sensor issue and a boost leak. After my sensor repair, I later encountered a similar oil residue situation that turned out to be a cracked intercooler hose causing a significant boost leak. The check engine light in my case would periodically reset even after cleaning the sensor connections until we addressed the underlying boost leak. The turbocharger was functioning properly, but the system couldnt maintain proper boost pressure due to the leak. A thorough pressure test of the entire intake system might be worthwhile. My repair ultimately involved: Cleaning sensor connections: 95 Euro, Replacing damaged intercooler hose: 150 Euro, New clamps for the turbo system: 45 Euro Getting both issues fixed resolved all symptoms, the jerking, whistling noise, and fuel consumption returned to normal. Given your similar mileage, I would recommend having the entire boost system inspected while they check the sensor wiring.

I appreciate the detailed response and breakdown of your repair experience. Your situation does sound quite similar, especially regarding the boost leak symptoms. The fact that you found both a sensor issue and a boost leak in your case is particularly relevant, as I'm seeing similar signs. The P0236 code and oil residue in my case definitely align with your experience. After reading about your repair process, I will ask my mechanic to: Check the air intake system for any leaks or cracks, Test the boost sensor wiring and connections, Inspect the intercooler hoses and turbocharger system thoroughly, Perform a complete pressure test The cost breakdown you provided is also very helpful for budgeting. Knowing it could be a combination of issues rather than just a faulty sensor helps set realistic expectations for the repair scope and cost. I will schedule an appointment with my mechanic tomorrow and have them check both the sensor connections and potential boost leaks. Will probably need a proper pressure test to identify all potential issues in the turbo system before proceeding with repairs.