I don't think the mechanic is advising you correctly. The Vanos is at the end of the cam and there are multiple cam caps holding the cam in place. The cams should not wear beyond the first cam cap - if it was worn in this manner the car most likely would have been coding like crazy besides running poorly and making a ton of noise.
Did you do an oil pressure test? Can you get some pictures and post them?
My understanding on the Vanos internal seals - when they start to fail they get noisey. I have never heard of this, but thinking it through, if they really fail they cannot build up enough pressure to advance or retard the timing as instructed by the engine computer. You should have been getting codes in this case. Did you have codes and ignore them? At this point the engine should have gone into a loop mode and not used the Vanos at all. I think the Vanos would just go all the way in one direction (don't know which one) - there are gears in there which would limit movement. I suppose it is possible the plastic pieces of the Vanos wore and/or cracked into pieces and the entire unit would wobble, but the car would run just awful and throw codes. When my Bank 2 vanos bolt came loose, the Vanos moved all the way to one side and the engine would not start.
Maybe someone will chime in with more thoughts. I have rebuilt 6 Vanos units, and done head work on three engines - I am having a hard time buying into what your mechanic is saying. S/he could be correct, but I need to see more proof. More background on how the engine was running and codes would also be helpful.
Get some pictures of the issues and you will get more responses.
Did you do an oil pressure test? Can you get some pictures and post them?
My understanding on the Vanos internal seals - when they start to fail they get noisey. I have never heard of this, but thinking it through, if they really fail they cannot build up enough pressure to advance or retard the timing as instructed by the engine computer. You should have been getting codes in this case. Did you have codes and ignore them? At this point the engine should have gone into a loop mode and not used the Vanos at all. I think the Vanos would just go all the way in one direction (don't know which one) - there are gears in there which would limit movement. I suppose it is possible the plastic pieces of the Vanos wore and/or cracked into pieces and the entire unit would wobble, but the car would run just awful and throw codes. When my Bank 2 vanos bolt came loose, the Vanos moved all the way to one side and the engine would not start.
Maybe someone will chime in with more thoughts. I have rebuilt 6 Vanos units, and done head work on three engines - I am having a hard time buying into what your mechanic is saying. S/he could be correct, but I need to see more proof. More background on how the engine was running and codes would also be helpful.
Get some pictures of the issues and you will get more responses.