Remove or Replace Trunk Lid Motor
 

Alright, I have to open the darn motor up to see what's inside - it's not the servo motor - it's something else - I'll figure it out how to fix it or get a new one - "H" version as Mishar said.

Cheers,

Louis

Thanks for the video. Its hard to tell if motor is weak or magnet is
weak?

It's definitely the magnet

If you work the trunk with the engine running it usually works perfectly due to the slightly higher voltage available to the magnet coil, so clamping the clutch harder. Electromagnets don't wear out or get weak over time.
My first thing to look into would be to increase the friction between the clutch plates, as I suspect the friction surfaces wear smooth. Try sanding the surfaces slightly, see if that works.

Just a question that may save you some time: when the motor can't open your trunk do you hear it speeding up because of clutch sliding or it is just dying before finally letting the lid go back down?

When mine does it I can hear the motor running and a groaning slipping type noise. That to me sounds like the motor is fine, but the clutch is slipping.

I can't really imagine "a groaning slipping type noise". :) If you ever had slipping clutch on a manual transmission car where engine start spinning faster but car doesn't follow it, than this clutch slipping would be similar. I've heard few of those poor performers, including mine, and all of them made a groaning dying sound.

Main problem of this actuator is a poor bearing design combined with fairly week motor strong enough when it is new, but as bearing wares big surface of that clutch start touching the housing and gears loose alignment creating additional resistance. Add poor hinges design and probable motor power lost over time and you need new actuator. But even that doesn't fix that broken toy sound, similar to the one made by the parking brakes. Really flagship sounds. :)

If you check lid design of D4 you will see completely different thing. It works faster and quieter.

I don't think there is a long term fix for the old design motor. I think if you want the automatic feature, the now motor design is the way to go.

Its a low speed short travel mechanism so I would think that bearing wear is unlikely. With regards the clutch slipping, the motor is running but the trunk isn't opening. The system is a geared one so has no slippage points in it apart from the clutch. Ergo for the motor to be turning, but the trunk not opening the clutch must be slipping. Backed up by the fact it works when engine is running and voltages are higher.

I don't think you can expect it to behave like a slipping transmission clutch as the motor runs at a constant speed so clutch slippage won't result in big noticable rpm changes.

It may be that we are listening to different malfunction cases. Yours is better. Just increase friction in that clutch and it will be as good as new.