# Noise while idling???



## shadybab123 (May 9, 2006)

Hey Guys,
Just bought a 1998 Nissan Altima GXE (auto). The car only has 69,000 miles on it and I just had one of the pulleys replaced. I was sitting in the Carl's Jr. drive-thru for about 3 mins when all of a sudden I hear a very High-pitched ringing noise coming from my engine. The sound kind of reminded me of a 'FLATLINE' when someone on TV dies, but it was very loud. I revved the engine a little bit and the sound stopped for about 10 seconds and then it comes right back. It only makes the sound when I am idling, when I am driving it is completely silent. I've read online that it could be the idle air control motor... But I'm not sure. PLEASE SOMEBODY HELP


----------



## Vandy-1 (Apr 14, 2006)

Sounds like the serpentine belt is trying to "wear into the pulley" hopefully your pulley
is aligned right with the belt and the tensioner is adjusted properly.OR a bearing is
on it's way out. Open the hood while it is idling and try to find where the sound is coming from.


----------



## shadybab123 (May 9, 2006)

I opened the hood and it kind of sounds like it is coming from behine the engine. I'm new to nissans so I'm not exactly sure how the engine bay is organized, but it sounded like it was coming from behind the engine on the passenger side.


----------



## shadybab123 (May 9, 2006)

I've heard two things so far as the problem. the alternator and the idle air control. The noise stops for a second if I rev the engine


----------



## Vandy-1 (Apr 14, 2006)

Maybe the bearings in alternator are going out ?or could be the iac, I guess.


----------



## shadybab123 (May 9, 2006)

Well I heard from a friend to try turning on the AC when it starts making the noise. Well, I did and sure enough the noise went away? Anybody know what this means? How much to repair including labor?


----------



## shadybab123 (May 9, 2006)

bump for help


----------



## LONDONDERRY (May 19, 2004)

shadybab123 said:


> bump for help



You said the noise was coming from behind the engine, I'm starting to think that your intake manifold gasket is starting to leak. The reason I point to this, is because you said the noise appears if its idling dissapears once you rev up the engine. How does the car idle is it a smooth or rough? 

If its not the gasket, then I would check the IACV. I don't think its the alt.

good luck 
frank


----------



## Darktide (Jul 29, 2004)

I'm not altogether sure why they would suggest turning the AC on when the noise starts up.... the only thing I can think of is that the AC Clutch is having some issues. And anything to do with the AC Compressor is sure to set the bank back quite a bit. If you did that my assumption would be that either the AC Clutch/clutch bearings or another component on the belt is having issues. The reason why I say another component on the belt is that maybe having the clutch engage on the AC is relieving some pressure on another component but that doesn't make a whole lot of sense.... but its always possible. I would try using a hose and by putting it up to your ear and moving the other end around you should be able to locate where the noise is coming from.... it works well on header leaks it should do a damn fine job on this too (actually I've done this numerous times so you should be good to go with it).

Good luck and let us know how it comes out.

Darktide :idhitit:


----------



## shadybab123 (May 9, 2006)

Well when it starts making this noise (After idling for a few minutes) and I turn on the ac, the noise stops. So somehow the noise is related to the ac (either directly or indirectly). Also I noticed that everytime I shut off the engine it makes this squeeling/whining noise for a second or two and then stops. Any ideas before I see a mechanic would help


----------

