Hot Air/Sawing sound when idle


I don’t know if these 3 items are related or not. I had an oil change this morning on my 05 Nissan Altima. My AC is now blowing hot air and there is a strange sound under the hood when I am stopped. It sounds like a sawing sound, don’t really know how to describe it. Like sawing metal. I’m really concerned.


unfortunately now that you got the wheel bearing fixed, a trip to the AC radiator shop sounds like it’s in your future.

does the sound go away when you turn off the AC switch?

how about when you rev the engine. does the noise change pitch or frequency?


I hadn’t turned the air back on since I realized it was only going to blow hot earlier today. Been using the good ole fashioned windows. I heard the wierd noise earlier when I was at a stop light and my radio was off, but it was so foreign to me, I figured it was another car. Then not too long ago, I was at the drive through with the radio off and heard it again. I only hear it when I’m stopped. There’s a pattern to it as well. It’s starts off quiet then gets louder, then stops. Then repeats.


Any other ideas?


If I heard strange noises coming from under the hood after an oil change, the FIRST thing that I would do is shut off the engine. Then, I would check the oil level and inspect the engine and the ground for evidence of oil leaking from the area of the oil filter!

Have you done this?

If the oil level appears to be normal, and if there is no evidence of leakage, then I would suggest trying to localize the noise. A short length of rubber hose, held to your ear while moving the hose around the engine compartment, should allow you to localize the noise. Then, you can report back to us on your findings.


I’ll try this. I didn’t really hear the noise until last night, so my daughter and I just rushed to get home and get in the house. My boyfriend is coming over to look at it this morning.

Do you think the sound is related to the air conditioner? Or probably just a coincidence?


an interesting problem is now that you got the wheel bearing fixed (quieted down) now you will hear the other noises.

have a look around with the hood up, and keep your hands away from the fan. whether it is stopped or not. it can turn on automatically and chew your fingers.