krwkim26

I have a 2012 nissan sentra SR, only 5 months old, 7,000 miles so far.. bought it brand new.
A few days ago, there was this loud rattling/vibrating noise coming from my engine when i would turn the AC on, however it would stop after a few seconds. I took it to nissan, they said it was the compressor, and for some reason it was very noisey, SOO.. they replaced it, under warranty thankfully...
Well, i got the car back last night, no issues.. until today- the sound is still there! Its not as loud, and not all the time as before but it definitley is there still. It happens about 5-10 sec after turning the AC on, and it only lasts a few secs.. as before.
The car is brand new like i said and has never had any issues til now.. The ac also works very well, its just that noise!
Im taking it back to nissan tomorrow.. in hopes they can figure it out... but does anyone have any suggestions?!

I also recorded the sound on my iphone! if i can figure out to upload it before the issue can be looked at again, i will.

wilburk

I know this is a tricky question, but what KIND of rattling is it? Like a little, tinny rattle from a loose bolt or nut? Or a big, vibrational rattling from a bigger piece? That might be a good place to start.

Can you find the A/C compressor and just poke around with your hand to see if it moves or if there's anything that's really obviously slapping around down there?

krwkim26

Ahh, let me see.. its loud enough to hear from inside of the car, all though im positive thats not where the source is... its definitely passed the firewall/under the hood.
Its a rattling, fan light noise.. you could compare it to a plane almost..
Maybe the fan motor? its also intermittent, so sometimes the noise is never made at all. I just dont know
Im wondering if nissan misdiagnosed the issue being the compressor.. i couldnt imagine having another "noisy" one put right back in.

I recorded a couple of sound clips.. not sure if i can post them on here or even how? I can send though email if you want to listen..