Rough S3 Idle Points to Failed Motor Mounts

Had a similar issue with my 2002 Audi A3 1.8T. After some noticeable vibration issues at idle, especially with the AC running, I discovered motor mount problems were indeed the cause. Initially thought it was just normal engine behavior, but the vibrations got worse over time. After seeing error codes and experiencing rough idling, I took it to a workshop. They found a damaged cable connection to the engine mount sensor, which was causing incorrect readings and affecting engine performance. The repair was relatively straightforward, they replaced the faulty wiring and connections for 95 Euro. The motor mount itself was actually still in decent condition, so no mount replacement was needed in my case. The fix completely resolved the vibration issues and error codes. With some experience working on VAG engines, I can say transmission mount and motor mount wear is fairly common on these models, but always check the electrical connections first before assuming mount failure. Could you share: Current mileage on your S3? Are you getting any specific error codes? Does the vibration change when shifting from P to D? Have you noticed any clunking sounds during acceleration? This information would help determine if your issue is similar to what I experienced or if you might be dealing with actual mount wear.

Had a similar issue with my 2002 Audi A3 1.8T. After some noticeable vibration issues at idle, especially with the AC running, I discovered motor mount problems were indeed the cause. Initially thought it was just normal engine behavior, but the vibrations got worse over time. After seeing error codes and experiencing rough idling, I took it to a workshop. They found a damaged cable connection to the engine mount sensor, which was causing incorrect readings and affecting engine performance. The repair was relatively straightforward, they replaced the faulty wiring and connections for 95 Euro. The motor mount itself was actually still in decent condition, so no mount replacement was needed in my case. The fix completely resolved the vibration issues and error codes. With some experience working on VAG engines, I can say transmission mount and motor mount wear is fairly common on these models, but always check the electrical connections first before assuming mount failure. Could you share: Current mileage on your S3? Are you getting any specific error codes? Does the vibration change when shifting from P to D? Have you noticed any clunking sounds during acceleration? This information would help determine if your issue is similar to what I experienced or if you might be dealing with actual mount wear.

Latest service was done at 170311 KM. After checking the workshop documentation, they replaced both left and right rubber mounts and mounting brackets last year. However, the vibration issue has returned. The error codes are P0507 and P0506. The vibration definitely changes when shifting from P to D and there is a noticeable clunking sound during hard acceleration. The transmission mount appears to be the likely culprit based on these symptoms, even though the engine mounts were recently replaced. Looking forward to your thoughts on whether I should check the transmission mount specifically.

Latest service was done at 170311 KM. After checking the workshop documentation, they replaced both left and right rubber mounts and mounting brackets last year. However, the vibration issue has returned. The error codes are P0507 and P0506. The vibration definitely changes when shifting from P to D and there is a noticeable clunking sound during hard acceleration. The transmission mount appears to be the likely culprit based on these symptoms, even though the engine mounts were recently replaced. Looking forward to your thoughts on whether I should check the transmission mount specifically.

Thanks for providing those details. Given my own experience with very similar symptoms on my A3, I strongly suspect your transmission mount is indeed the culprit here. Even with new engine mounts, a worn transmission mount can cause these exact vibration issues and the clunking during acceleration. When I faced this problem, replacing just the engine mounts didnt fully solve it. The P0506/P0507 codes typically indicate idle control issues, which in my case were triggered by excessive movement from a failing transmission mount. The clunking sound during hard acceleration is particularly telling, this was the exact symptom that led me to discover my transmission mount had deteriorated, despite having relatively new motor mounts. The repair cost me around 280 Euro for parts and labor. The vibration issues completely disappeared after replacing the transmission mount, and the error codes cleared up as well. A quick test you can do: Have someone watch the engine movement while you shift between P and D. Excessive movement likely confirms a defective transmission mount. The rubber mount material tends to break down over time, especially with our generation of VAG engines.

Thanks for providing those details. Given my own experience with very similar symptoms on my A3, I strongly suspect your transmission mount is indeed the culprit here. Even with new engine mounts, a worn transmission mount can cause these exact vibration issues and the clunking during acceleration. When I faced this problem, replacing just the engine mounts didnt fully solve it. The P0506/P0507 codes typically indicate idle control issues, which in my case were triggered by excessive movement from a failing transmission mount. The clunking sound during hard acceleration is particularly telling, this was the exact symptom that led me to discover my transmission mount had deteriorated, despite having relatively new motor mounts. The repair cost me around 280 Euro for parts and labor. The vibration issues completely disappeared after replacing the transmission mount, and the error codes cleared up as well. A quick test you can do: Have someone watch the engine movement while you shift between P and D. Excessive movement likely confirms a defective transmission mount. The rubber mount material tends to break down over time, especially with our generation of VAG engines.

Based on the input from others and my own observations, I believe the transmission mount requires immediate attention. The symptoms I'm experiencing, vibration changes between P and D, clunking during acceleration, and idle control codes, all point to transmission mount failure despite my recent engine mount replacements. The rough idle with P0507/P0506 codes, combined with the fact that both rubber mounts were replaced last year, suggests the transmission mount has worn out independently. The vibrations getting worse with AC engaged further supports this diagnosis. A failed mount could explain all my current issues, and the repair cost around 280 Euro seems reasonable considering the symptoms. I will schedule a transmission mount inspection and likely replacement soon, as continuing to drive with these symptoms could lead to additional problems. Will update once I confirm whether the transmission mount was indeed the root cause of these vibration and idle control issues. The consistent feedback about mount wear on these engines has been very helpful in narrowing down the problem.

Based on the input from others and my own observations, I believe the transmission mount requires immediate attention. The symptoms I'm experiencing, vibration changes between P and D, clunking during acceleration, and idle control codes, all point to transmission mount failure despite my recent engine mount replacements. The rough idle with P0507/P0506 codes, combined with the fact that both rubber mounts were replaced last year, suggests the transmission mount has worn out independently. The vibrations getting worse with AC engaged further supports this diagnosis. A failed mount could explain all my current issues, and the repair cost around 280 Euro seems reasonable considering the symptoms. I will schedule a transmission mount inspection and likely replacement soon, as continuing to drive with these symptoms could lead to additional problems. Will update once I confirm whether the transmission mount was indeed the root cause of these vibration and idle control issues. The consistent feedback about mount wear on these engines has been very helpful in narrowing down the problem.