Lolekbolek123

Hello, I own an Audi A3 2.0 TFSI quattro sportsback, year 2016, and I am experiencing the following issues with the Haldex - Quattro system: Quattro only works when the car is cold, usually for the first 30–60 seconds of driving. When the car warms up, the quattro stops functioning. When the quattro system engages, there is a strange grinding/squeaking noise coming from the rear of the vehicle, which disappears when AWD is no longer active. All four tires are the same size and wear. The Haldex pump, controller, and oil have been replaced, and the Haldex pump filter has been cleaned, yet the issue persists. I would like your advice on the most likely cause, and what repair procedure you would recommend. Additionally, I would like an estimate of the repair costs. Thank you very much for your help and professional guidance.