N400 Automatic Transmission Slippage

Hey there, I had similar issues with my N400. Those grinding noises are a real pain, aren't they? Did the error code specifically point to the torque converter? The lock-up clutch inside the torque converter makes the direct mechanical connection between the engine and transmission. When that clutch goes bad, it can cause all sorts of weird shifting problems and those lovely noises. Was it slipping more when the car was hot?

Thank you for your response. The error code did indeed indicate a fault within the torque converter, specifically referencing the lock-up clutch mechanism. I can confirm that the slippage does seem to be more pronounced when the engine and transmission have reached their normal operating temperatures. Did you also experience the illumination of both the check engine light and the transmission indicator light, and was the diagnostic error code you retrieved identical to mine?

Yep, check engine and transmission light both came on. The code was definitely related to the torque converter lock-up clutch. If it's acting up more when it's hot, it's almost certainly the converter. The heat thins the fluid, making the slippage worse. Honestly, I'd bite the bullet and take it to a workshop you trust. They'll be able to confirm it and give you a proper quote.

I appreciate your confirmation and advice. Based on your experiences and the symptoms, I have decided to proceed with a professional diagnosis and repair at a reputable workshop. The estimated cost for the repair, including parts and labor, is approximately 2120€, which includes replacing the defective torque converter. Thank you again for your assistance.