SQ5 Idle Vibration Points to Motor Mount Issues

As someone with moderate experience working on Audi engines, I dealt with similar vibration issues on my 2013 S4 3.0T last year. The symptoms you describe match what I experienced, excessive engine vibration at idle that worsened over time. Initially thought it was a defective engine mount, but my workshop found the root cause was actually a faulty wiring connection to the engine control module. The loose connection was causing irregular idle behavior and storing error codes. The transmission mount and other mounting brackets were inspected but found to be in good condition. The repair involved cleaning and properly securing the connector pins, plus replacing one damaged wire. Total cost was 95 Euro for parts and labor. The mount failure symptoms disappeared completely after fixing the electrical connection. To better assist with your specific case, could you share: What error codes are stored? Does the vibration change with engine temperature? Are there any unusual sounds accompanying the vibration? Have you noticed any fluid leaks around the engine bay? These details would help determine if your issue stems from the same root cause or if you are actually dealing with mount problems. The 3.0T engines are generally quite reliable, but proper diagnosis is key.

Thanks for the detailed reply. At 165873 KM, I am starting to see the vibration worsen, particularly when the engine is cold. Just checked and getting error codes P0507 and P1338. The rubber mount on the passenger side looks visibly cracked and oil-soaked, which seems to match other failed mount symptoms mentioned here. No fluid leaks spotted yet, but there is a distinct knocking sound when shifting between drive and reverse. The motor mount deterioration appears to be causing most of these vibration issues, so I will likely need the transmission mount checked as well during service.

Thanks for those additional details. Your symptoms are nearly identical to what I experienced before replacing my engine mount on my S4. The oil-soaked, cracked rubber mount you described is a telltale sign of mount wear, much more definitive than my initial electrical suspicion. The knocking sound during gear changes is particularly telling, I had the same issue before replacing both the engine mount and transmission mount as a set. The defective engine mount was allowing excessive movement, which stressed the transmission mount until it also showed signs of wear. Those error codes (P0507/P1338) often appear with mount failures because the excessive engine movement affects idle control. My repair involved: Replacing both motor mounts (350 Euro), New transmission mount (280 Euro), Labor costs (225 Euro) The repair completely resolved the cold start vibrations and knocking sounds. Given your mileage and symptoms, I would strongly recommend replacing both mounts rather than just the visibly damaged one. This prevents having to do the job twice when the second mount inevitably fails. Consider having your workshop check the other mounting brackets while they are doing the work. Mount wear often occurs across multiple points when one fails.

Thanks for the insights. I think I will move forward with replacing both mounts since the symptoms match so closely with your experience. The oil-soaked mount and knocking sounds during gear changes are pretty much identical to what you described. Will get the full mounting bracket inspection done while they have it apart. Based on the repair costs you shared, I should budget around 855 Euro for the complete job. The vibration issues are definitely getting worse during cold starts, so better to address it now before the transmission mount fails completely. Just hoping the other mounting components look okay during inspection. I will schedule the repair next week and plan to have them fully document the mount failure with photos. This should help other owners identify similar problems. Really appreciate the detailed breakdown of the repair process and costs.