SQ8 Transmission Warning Lights: Torque Converter Fail

Had similar symptoms with my S7 last year, grinding during gear changes and transmission slipping are classic signs of torque converter fault. My automatic gearbox started acting up around 62000 km with identical warning lights. The transmission repair required removing the entire gearbox to access the torque converter assembly. The lock-up clutch inside the converter was severely worn, causing the slipping and grinding. This explained the harsh shifting and power loss during acceleration. A proper fix involved replacing the complete torque converter unit and transmission fluid. The clutch problem was quite serious, continuing to drive risked damaging other transmission components. The repair took about 4 working days at a specialized transmission shop. This is a known issue that can affect these 4.0L powertrains. Would strongly recommend having it diagnosed and repaired promptly by a transmission specialist rather than a general dealer. The converter fault typically doesnt fix itself and delaying repairs often leads to more extensive transmission damage. Consider requesting a full transmission inspection while they have it apart, including the valve body and solenoids. This helps prevent future automatic gearbox issues.

Thanks for the detailed response on the torque converter issue. My experience was very similar, the engine surge and transmission warning lights were spot on. I also noticed the same problems with the automatic transmission slipping between gears. Can you share roughly what the repair ended up costing you? Curious if the pricing was comparable to what I was quoted. Also wondering how the transmission has been performing since the fix, any other issues pop up or has it been smooth sailing? I am leaning toward taking it to a transmission specialist rather than the dealer based on your feedback about the lock-up clutch replacement. The 4-day turnaround time seems reasonable too.

Since getting the automatic transmission torque converter lock-up clutch repaired, the gearbox has performed flawlessly with no issues whatsoever. The repair cost came to 2120 Euro total, which included a complete converter replacement along with fresh transmission fluid and filter. The transmission specialist did a thorough job diagnosing and fixing the converter failure. The engine surge symptoms and warning lights completely disappeared after the repair. Shifts are now butter smooth with none of the grinding or slipping that was happening before. The automatic gearbox has now done another 15000 km without any problems. The specialist also performed a full transmission health check while they had it apart, which gave peace of mind that no other components were affected by the clutch problem. Going with a transmission specialist rather than the dealer was definitely the right choice. They knew exactly what they were dealing with and had experience with this specific converter fault on these powertrains. The 4-day turnaround was accurate, they had the car back to me right on schedule.

Thanks for the helpful advice. I took my car to a transmission specialist last week after getting those concerning symptoms. They confirmed it was indeed the torque converter causing the problems. The total repair bill came to 2350 Euro which included replacing the entire converter unit and flushing the transmission fluid. The automatic transmission specialist found significant wear on the lock-up clutch, which explained the slipping and grinding I was experiencing. The whole job took about 3.5 days from drop-off to pickup. Really glad I chose a dedicated transmission shop over the dealer, these guys clearly knew what they were doing with converter failure issues. They even showed me the worn parts and explained exactly what had failed. Been driving for a few days now and the difference is night and day. No more engine surge, grinding, or warning lights. The gearbox shifts perfectly smooth again. Definitely recommend anyone facing similar symptoms to get it checked out promptly by a specialist before the clutch problem causes more extensive damage.