Audi S4 engine knocking issue requiring engine replacement on Audi S4

Some Audi S4 owners report experiencing engine knocking issues that may necessitate an engine replacement, often accompanied by turbo failure, as noted in cases where both problems arose prior to an ECU tune. These owners have found that engine knocking could be linked to rod knock, indicating potential bearing or bolt problems. To troubleshoot misfires in specific cylinders, professionals may recommend swapping direct injectors, spark plugs, and ignition coils. When considering a replacement engine, it is crucial for owners to assess factors such as compression levels, oil pooling, and the overall condition of the engine to ensure compatibility. Additionally, common issues like dual-clutch transmission problems should be factored into the diagnosis of engine-related concerns. Symptoms such as tapping noises, knocking, and shaking during acceleration without dashboard warning lights can signal serious underlying engine issues that require prompt attention. Owners are advised to inspect specific components like lifters and exhaust systems to pinpoint the source of abnormal sounds and vibrations.