If the AC is off - car sounds normal, drives normal. 2003 Maxima SE, AT.

If i turn ON the AC and especially if it's too hot outside, every time i take off from a stop....i hear something under the hood revving up. Sounds like it spins at very high RPM and then the sound goes away.
The RPM on the tach do not look weird, no spikes, no AT related (i think) but the AC noise comes mostly around 2000-2400rpm and then i don't hear it.
If i rev the engine while the car is moving ... i kind of don't hear the AC noise.
Not sure if it's RPM related, heat related ....really confusing. AC blows cold air just fine.

What could be causing this?

I did "recharge" the AC 3-4 weeks ago. I used a recharge kit from auto parts store. Initially i overfilled it and the AC compressor stopped working. Then, i released some pressure and made sure the pres. level is within the specified range. AC started to work again. Not sure if this is related.


Thanks for any feedback!

 

You probably damaged the compressor by over charging it. Get a manifold test set on it to properly check pressures.

 

Hmm... it was "overcharged" for no more than 4-5 minutes. It stopped working as soon as i reached the "red zone". Then i released the pressure back to the "green" and it started working fine.

Could all this have cause a permanent damage that would cause the AC to "rev" high?

How do i do this? What do i need to buy? I don't have a trusted mechanic who i can let "diagnose" this. I am willing to try doing as much as possible by myself.


Thank you!

 

IMO your IAVC is faulty, it's job is to maintain idle under load or no load conditions. I would let the stealership see if they can adjust it correctly.....or do and idle relearn yourself!

 

My idle rpm are fine with or without the AC being ON. When i have the AC ON ... or the AC OFF => my idle is rock solid, according to the tach. Engine feels fine.

It's just the "revving" noise that i get with the AC on that is abnormal.

 

When you use the word rev or revving It meant idle,... so sorry! Good luck with someone understanding your sitation!

 

sounds like the fans kicking in.