I drive an '08 6 speed and I've been noticing lately that when I rev past 4k rpm there is a clicking rattle from the engine compartment. I've taken it to the dealer and they said something about the heater coil being dirty and causing it...they fixed it temporarily and then i've recently noticed it's back. Has anyone else had this problem before?

 

Ya if they said it was the heater core then they are correct as that was a common problem in 07s and early 08s and a TSB was issued by infiniti to fix the problem, just go back and they should be able to fix it for you.

 

My '08 6 speed has the same problem. Dealer says they are replacing the heater core. The clicking started at 3k for me.

 

^ ya theres a tsb for that where they just clean it out, but if you're getting a new one then thats just great!