Greetings, this is my first post in these forums after a couple of years of membership. I own a '99 E36 M3 and an '03 540i M-Sport Touring. My M3 has had "crickets" or chirping for quite some time, I assumed at 95K I just needed to replace the original deflector, pulleys and tensioners and the noise would go away. Sadly, after replacing those parts the crickets are still there. The belts are maybe 2 years old with less than 10K miles and do not have cracks in them. The water pump is about 3 years old with about 10K miles on it, the alternator is original. Here are some patterns/info I've discovered -Having AC on or off does not seem to make a difference. -The sound never happens at rest while revving the engine, only while driving. Which of course makes it really hard to determine where the noise is coming from. -The sound is not constant, but it seems to occur only as the revs pass between 2,000 to about 2,500 RPM, which is typically fairly quick so it's just a little chirp or 'cricket' sound. 2nd gear is pretty consistent, 4th gear seems to really bring it out, perhaps because it passes through the revs a little slower in that gear. Sometimes in fourth gear holding at just the right RPM, a little over 2K, I can get it to continue constantly. Heading out to Mid-Ohio for CCA HPDE in a few weeks, 10 hour drive to get there, want some piece of mind! Just looking for possible direction/ideas. Alternator? VANOS? Thanks!