Customer states that engine overheats. No MIL. No related DTCs are stored. Various parts have been replaced under warranty for the condition noted above, but no issues were identified with these parts. In an effort to gain information on the overheat condition for the vehicles listed above, we are asking that you contact the Audi Technical Assistance Center (TAC) before replacing any parts. This will assist us in diagnosing any potential issues with the condition noted above. No changes to production have been made, as no issue has been identified.