SQ7 TDI Power Loss Linked to Faulty Intake Flaps

Had the same symptoms in my A6 3.0 TDI from 2019. The reduced power and rough running turned out to be a faulty intake manifold control unit. The air intake flaps were stuck, causing uneven air distribution and affecting engine performance significantly. The repair involved replacing the entire intake manifold assembly since the control motor and flaps are integrated. This is a known weak point in these engines. The hissing noise you describe matches what I experienced, it was air escaping through damaged seals in the intake system. The symptoms got progressively worse, eventually triggering multiple fault codes related to intake flap position and air mass readings. This isnt a repair you want to postpone, as continued operation can lead to increased carbon buildup and potential turbo issues. After replacement, engine performance returned to normal immediately. The rough running and jerking disappeared completely. Worth noting that the intake manifold needs proper programming after installation to ensure correct flap operation.

Thanks for sharing your experience. It sounds exactly like what I am dealing with now, same airflow control and engine performance issues. My SQ7 has been running much smoother since the repair, though the process was not cheap. Did you remember approximately how much you paid for the intake manifold replacement and programming? Also curious if youve had any related issues pop up since the repair was done? These reduced power symptoms can sometimes hint at other underlying problems.

Thanks for asking about the repair costs. After visiting the mechanic last month, the airflow control issue was completely resolved. The total bill came to 465 Euro for replacing the defective intake manifold flap control switch. I have not experienced any reduced power problems since the fix. The car runs perfectly now with the new manifold flap control unit installed. No engine performance issues or strange noises during acceleration. The repair was definitely worth the investment as the engine response is back to normal and fuel consumption has improved significantly. For anyone else experiencing similar symptoms, addressing intake manifold problems promptly helps prevent additional engine damage. A properly functioning flap control system is crucial for optimal air intake and engine performance.

Thanks everyone for the helpful feedback. After seeing my car was showing the exact same symptoms, I took it to the shop last week. The mechanic confirmed it was indeed the intake manifold flap issue. The repair bill ended up being 780 Euro total, more than I hoped but worth every cent. They replaced the entire intake manifold assembly and reprogrammed the control unit. The engine light is now gone and the car runs like new again. My mechanic showed me the old part, the flap control motor was completely seized up and there was notable carbon buildup around the valves. He mentioned catching these intake system problems early helps prevent more expensive engine repairs down the road. After a week of driving, the engine performance is fully restored. No more hissing noises or jerky acceleration. Fuel consumption is back to normal too. Really glad I got this sorted before any additional problems developed.