Ticking noise in my 428i and three shops can't figure it out, need a real specialist

[keatonketteridge]

I've got a 2015 428i that's been making this weird ticking noise from the engine bay for about two months now. It's not constant, comes and goes, sometimes louder when the car is cold. I took it to three different garages in Abu Dhabi and each one gave me a different answer. One said it was the lifters, another said it was the timing chain, and the third just told me to keep driving until something breaks which is honestly the worst advice I've ever heard. I'm not a mechanic but I know enough to realize these engines have known issues and I don't want to wait for a catastrophic failure. A friend who owns an M3 told me I should stop wasting time with general shops and find a Certified BMW engine repair specialist near Khalifa City since that's close to where I live and I can drop it off easily. I'm hoping someone here has actually used a specialist for a similar noise and can tell me if it's worth it. Did they find the real cause or just replace parts until the noise went away? I'm willing to pay for proper diagnosis but I'm done with guesswork.