Does the car ‘judder’ when u turn it off? Like it turns off in a hard/aggressive way if u know what i mean. Either the el part is gone/or the oil went through it to the electric part or just needs to be cleaned. Usually while driving this should not make the car shake/judder. Just once u turn it off and it pulls the engine light on. If the unit is replaced and the problem is the same(the turn off thing/eng light) check the wires from it to the eng computer or just make a ‘bypass’ /new wires if the problem is intermittent. U should check the wires anyway before paying for a new unit, although wires werent usually the problem on audis, more on wv. If u clean it, if it has alot of sooth, position the motor so that the electric part is facing up, so no cleaner can get in it trought the seals.
Edit: saw your last post, check the post i made in the other thread. This engine flap motor doesnt usually affect driving performance.
Cheers