So here's the latest on my Vanos rattle and my attempts to get it repaired under CPO.

Ever since I bought the car, I have had the classic Vanos rattle. I typically hear it under load between 2,500 and 3,500 rpms, and exactly at 2,400 rpms in neutral.

I also have a leaking VCG, so my plan was to head to the dealer and get the Vanos replaced under CPO, which would also get me a new VCG.

Made an appointment at BMW of Atlantic City and dropped the car off at 8am Tuesday morning. Service adviser tells me my car will be ready for pickup by 5pm. At around 3:30pm, the service adviser calls to advise me that they're running behind and haven't gotten to my car yet. He calls back at around 5pm and tells me that the tech thinks he hears what I'm talking about but wants to try it on a cold motor in the morning.

Soooo.... service adviser calls me this morning and tells me that, "the tech is having trouble hearing the sound or recreating it."

Wrong answer.

I advise the adviser that it is not open to interpretation. The engine is rattling, and the rattle is coming from the front of the valve cover. I further advise the adviser that I will be coming down and will reproduce the sound myself if need be.

Service adviser tells me that he believes me and that I am welcome to try and reproduce the sound for the tech.

So I returned this afternoon to continue my mission. I went for a five mile highway drive with the tech and then returned to the dealership where we proceeded to pop the hood and listen. I was able to recreate the rattle-- amazingly exactly at 2,400 rpms like I had reported.

The tech admitted to hearing it, but then tells me that if he replaces the Vanos, there's no guarantee that the sound won't return.

I tell him that if he doesn't replace it, I can guarantee him the sound won't go away.

The tech agrees to plead my case to the service adviser.

They agree to replace my Vanos.

So, in a few weeks I'll be back for a new Vanos and VCG.

The moral of the story is, be a squeaky wheel and don't take no for an answer.