clicking sound from motor when ac on

[370zdaily1414]

Hey guys, I'm new to the forums! I'm particularly stumped on an issue. My girlfriend drives a 2011 2.5 altima coupe. The problem started a couple months ago and I still can't find where the noise specifically comes from. The car has a normal startup, no abnormal noises. As soon as I put the car in reverse and the AC is on,a clicking noise is heard from the engine bay. No it is NOT the compressor clicking on, or the radiator fan. The rpms do NOT fluctuate in any specific pattern in relation to the noise occuring. The noise rarely occurs when the ac is off. The noise occurs in reverse and drive. When the car is in park or neutral it does not occur. I've read something concerning a valve compressor clutch but that was for the nissan quest. If anybody can shed some light on the subject I'd appreciate it.

[AlexM.]

I think it's the alternator. I had a similar issue and got my alternator replaced under warranty and the problem is gone. The techs couldnt find what in particular was wrong with it but they were able to narrow down the noise to the part.

[SanoSuKe]

Welcome to NICO! Hope Alex's reply was of help to you. Keep us updated

[370zdaily1414]

Well... after 5 months, the mysterious sound has quit....if it returns I will change the alternator!