Not the usual ticking noise..

[zeroboot]

This issue on my e70 X5M is driving me crazy...

A few months ago I started noticing that I would have some sort of 'ticking' noise that only occurs under specific circumstances...that is, when I am pressing on the gas pedal. When its at idle, or coasting, or any other time, the ticking does not occur...its ONLY when I am asking for fuel. (this is not the normal/expected, at idle ticking noise)

I did not have this issue until after the injectors were replaced (Dec '15).
Its been sitting with the dealer for the past 3 weeks getting other stuff done (AC Evaporator, air suspension, lower steering joint assy, and some other stuff they found along the way) but primarily to try and determine what is causing this sound...so far they have no root cause.

It must be something in the fuel delivery system...Im guessing...as it only occurs when the gas pedal is pressed. It is a constant tick, it doesnt vary with speed. If it was in the cylinder head, I would imagine the ticking would be there constantly.

I spoke at length with the shop foreman, who is a good guy that I have talked to many times, and was very honest and up front about how they can do certain things to remedy these kinds of issues, and can replace things within their level of approval, but obviously cant just drop a new engine in (although he would love to). Their next step is to replace the HPFPs, although they admit it is likely not the issue. From there, they are talking about pulling the cylinder head apart and replacing valve train components. Again, not sure how that could be the issue, given there is no ticking at idle.

Just putting this on here, hoping maybe someone else might have encountered this issue themselves or has an idea what it might be...because right now, BMW is doing the 'try this and see what happens' game. Seems they don't really have a good procedure to troubleshoot noises of unknown origin.

Would the new injectors tick ONLY when I'm on the gas pedal? No idea if I should worry about this or not...BMW's response so far doesn't give me a lot of comfort.