Helicoil kit to repair idler pulley thread - M6

[ChrisMCoupe]

My M6 is in with BMW at the moment having work done on the Vanos, new high pressure oil pump plus some other bits and pieces I believe.

Whilst they were doing this job, they noticed that the idler pulley (I think for the Air-con) was just spinning in the thread. They rang me yesterday basically saying, worst case scenario is that it will need a new block plus crank etc (a nice hefty bill to the warranty company), however they now say they can safely fix it with a helicoil kit?

Now I'm not sure what this is exactly, but should I be happy that this is a safe and good way of fixing it, or should I be thinking this is a bodge fix to save themselves money?

[ChrisMCoupe]

Thanks for the advice chaps. I guess the quandary I'm in is whether or not I'd like the BMW technicians to be heli-coiling my block or trust them rebuilding my bottom end

I want to first find out if this helicoil is an approved BMW fix or not, and as mentioned, get it in writing if it isn't and that warranty will cover any future issues with it.