Audi S5 Rough Idle Points to Fuel System Troubles

I had a similar issue with my 2018 Audi A5 diesel last year. Having worked on various cars as a hobby mechanic, I can share my experience with this. Started with similar symptoms, rough idle and jerky acceleration. Initially thought it was related to the fuel pump or spark plugs, but after taking it to the workshop, they diagnosed a leak in the exhaust system. The oxygen sensor readings were inconsistent due to the exhaust leak, causing the engine management system to run rich/lean at irregular intervals. The repair cost was 265 Euro including parts and labor. The fix resolved both the rough idle and acceleration issues completely. The check engine light also cleared up after the repair. Before suggesting specific solutions for your S5, it would help to know: Current mileage on your vehicle, When was the last maintenance service done, Are there any other unusual sounds, especially from the exhaust area, Which specific error codes are stored These details would help determine if your issue is similar to what I experienced or potentially something different in the fuel system.

I had a similar issue with my 2018 Audi A5 diesel last year. Having worked on various cars as a hobby mechanic, I can share my experience with this. Started with similar symptoms, rough idle and jerky acceleration. Initially thought it was related to the fuel pump or spark plugs, but after taking it to the workshop, they diagnosed a leak in the exhaust system. The oxygen sensor readings were inconsistent due to the exhaust leak, causing the engine management system to run rich/lean at irregular intervals. The repair cost was 265 Euro including parts and labor. The fix resolved both the rough idle and acceleration issues completely. The check engine light also cleared up after the repair. Before suggesting specific solutions for your S5, it would help to know: Current mileage on your vehicle, When was the last maintenance service done, Are there any other unusual sounds, especially from the exhaust area, Which specific error codes are stored These details would help determine if your issue is similar to what I experienced or potentially something different in the fuel system.

I had a similar issue with my 2018 Audi A5 diesel last year. Having worked on various cars as a hobby mechanic, I can share my experience with this. Started with similar symptoms, rough idle and jerky acceleration. Initially thought it was related to the fuel pump or spark plugs, but after taking it to the workshop, they diagnosed a leak in the exhaust system. The oxygen sensor readings were inconsistent due to the exhaust leak, causing the engine management system to run rich/lean at irregular intervals. The repair cost was 265 Euro including parts and labor. The fix resolved both the rough idle and acceleration issues completely. The check engine light also cleared up after the repair. Before suggesting specific solutions for your S5, it would help to know: Current mileage on your vehicle, When was the last maintenance service done, Are there any other unusual sounds, especially from the exhaust area, Which specific error codes are stored These details would help determine if your issue is similar to what I experienced or potentially something different in the fuel system.

After 100908 KM and a recent service last month, I discovered the root cause was a combination of a faulty ignition coil and crankshaft sensor. The error codes pointed to engine misfire issues. Had them both replaced along with the air filter since it was quite dirty. Total repair came to 480 Euro and completely resolved the rough idle and jerky acceleration. The check engine light is now off and the car runs smoothly again. This might help others facing similar symptoms with their S5.

After 100908 KM and a recent service last month, I discovered the root cause was a combination of a faulty ignition coil and crankshaft sensor. The error codes pointed to engine misfire issues. Had them both replaced along with the air filter since it was quite dirty. Total repair came to 480 Euro and completely resolved the rough idle and jerky acceleration. The check engine light is now off and the car runs smoothly again. This might help others facing similar symptoms with their S5.

After 100908 KM and a recent service last month, I discovered the root cause was a combination of a faulty ignition coil and crankshaft sensor. The error codes pointed to engine misfire issues. Had them both replaced along with the air filter since it was quite dirty. Total repair came to 480 Euro and completely resolved the rough idle and jerky acceleration. The check engine light is now off and the car runs smoothly again. This might help others facing similar symptoms with their S5.

Having gone through similar issues with my A5, your diagnosis and repair approach makes perfect sense. The combination of a faulty ignition coil and crankshaft sensor often creates these exact symptoms. When my oxygen sensor readings were off, I initially thought it was just the exhaust leak, but having seen your case, these components can definitely cause similar behavior. Good call on replacing the air filter while doing the work. Dirty filters can compound ignition problems and cause additional stress on engine components. The 480 Euro repair cost seems reasonable for the parts and labor involved, especially considering the comprehensive fix you got. The crankshaft sensor is actually a common failure point in these engines, and when it starts acting up, it often triggers issues with the ignition coil performance. This explains why replacing both components together solved the problem completely. This is valuable information for other owners experiencing uneven engine running and jerky acceleration. Always worth checking these components along with fuel system parts when troubleshooting similar issues.

Having gone through similar issues with my A5, your diagnosis and repair approach makes perfect sense. The combination of a faulty ignition coil and crankshaft sensor often creates these exact symptoms. When my oxygen sensor readings were off, I initially thought it was just the exhaust leak, but having seen your case, these components can definitely cause similar behavior. Good call on replacing the air filter while doing the work. Dirty filters can compound ignition problems and cause additional stress on engine components. The 480 Euro repair cost seems reasonable for the parts and labor involved, especially considering the comprehensive fix you got. The crankshaft sensor is actually a common failure point in these engines, and when it starts acting up, it often triggers issues with the ignition coil performance. This explains why replacing both components together solved the problem completely. This is valuable information for other owners experiencing uneven engine running and jerky acceleration. Always worth checking these components along with fuel system parts when troubleshooting similar issues.

Having gone through similar issues with my A5, your diagnosis and repair approach makes perfect sense. The combination of a faulty ignition coil and crankshaft sensor often creates these exact symptoms. When my oxygen sensor readings were off, I initially thought it was just the exhaust leak, but having seen your case, these components can definitely cause similar behavior. Good call on replacing the air filter while doing the work. Dirty filters can compound ignition problems and cause additional stress on engine components. The 480 Euro repair cost seems reasonable for the parts and labor involved, especially considering the comprehensive fix you got. The crankshaft sensor is actually a common failure point in these engines, and when it starts acting up, it often triggers issues with the ignition coil performance. This explains why replacing both components together solved the problem completely. This is valuable information for other owners experiencing uneven engine running and jerky acceleration. Always worth checking these components along with fuel system parts when troubleshooting similar issues.

Thanks for the detailed follow-up. The garage explained that worn ignition coils paired with a failing crankshaft sensor often trigger engine misfire conditions, which matches exactly what I experienced. They showed me how the dirty air filter was restricting proper airflow, potentially making the rough running worse. While 480 Euro felt steep initially, seeing how the car runs now makes it worth every cent. The mechanic mentioned that the fuel injectors and other components looked fine during inspection, which was a relief since those would have been much more expensive to replace. Looking back, the jerky acceleration and rough idle were classic symptoms of these failing parts. Hopefully my experience helps others diagnose similar issues with their S5 before the problem gets worse. Really appreciate everyone who took time to share their knowledge and experiences. It helped me better understand what I was dealing with and what questions to ask at the shop.

Thanks for the detailed follow-up. The garage explained that worn ignition coils paired with a failing crankshaft sensor often trigger engine misfire conditions, which matches exactly what I experienced. They showed me how the dirty air filter was restricting proper airflow, potentially making the rough running worse. While 480 Euro felt steep initially, seeing how the car runs now makes it worth every cent. The mechanic mentioned that the fuel injectors and other components looked fine during inspection, which was a relief since those would have been much more expensive to replace. Looking back, the jerky acceleration and rough idle were classic symptoms of these failing parts. Hopefully my experience helps others diagnose similar issues with their S5 before the problem gets worse. Really appreciate everyone who took time to share their knowledge and experiences. It helped me better understand what I was dealing with and what questions to ask at the shop.

Thanks for the detailed follow-up. The garage explained that worn ignition coils paired with a failing crankshaft sensor often trigger engine misfire conditions, which matches exactly what I experienced. They showed me how the dirty air filter was restricting proper airflow, potentially making the rough running worse. While 480 Euro felt steep initially, seeing how the car runs now makes it worth every cent. The mechanic mentioned that the fuel injectors and other components looked fine during inspection, which was a relief since those would have been much more expensive to replace. Looking back, the jerky acceleration and rough idle were classic symptoms of these failing parts. Hopefully my experience helps others diagnose similar issues with their S5 before the problem gets worse. Really appreciate everyone who took time to share their knowledge and experiences. It helped me better understand what I was dealing with and what questions to ask at the shop.