A whistle from engine bay. possible A/C problem

[MarineNSX93]

So, I have a slight whistle coming from the engine bay. I had Ramon from Niguel Motors listen to it and he said it was my A/C compressor bearing. I hope it is. I have had no loss of power and the car works great! The A/C is now just starting to fail, I don't use it much so I don't mind. How many of you have had this problem and also how many have just removed the entire A/C system from the car? I don't want to pay money to fix it. Or is there a way to shut it off with fuses or something? Any advise, thanks.

 

[brettowen]

I've never had this issue but unless you're planning on keeping your NSX forever, I'd recommend repairing your A/C vs. removing the entire unit. Just my .02.

 

[JD Cross]

On my 91 I had a whining sound when I turned on my A/C so am replacing my compressor and will check the A/C belt pulley bearing too.
I am driving with the A/C turned off on the CCU until I do the repair.

I'd suggest you will lose a lot of value on your car if you let the whole A/C system degenerate.
You may not want the A/C but another owner might.
If a new owner is faced with having to redo the entire system (compressor, dryer, condenser etc) it will run into thousands of $

 

[Rope]

Funny you mention the whistle, mine started that today. It is a faint whistle when the A/C is on. I am going to look into it as well.

 

[Dr. JL]

My Land Cruiser AC compressor just started chirping. Toyota tech said its a common problem with the bearing. Maybe your problem too. I'd repair the system. It's easy and relatively inexpensive.

 

[captngaryr]

I have a whistle in my engine as well. Does the whistle go away when you turn off the climate control?

 

[MarineNSX93]

Nope its goes all the time. The A/C I would say turns on 1/2 the time. The whistling may be getting quieter, can never tell since my car is loud and I may be getting used to it. you can only hear it at idle and with the engine hatch open.

 

[captngaryr]

Mine only occurs at highway speeds, and only at certain loads and RPMs, which makes it very hard to diagnose.

 

[shawn110975]

funny I read this thread the other day and now mine it making a whistle sound in the 6-7K RPM range at 65 mph with a/c off
Im thinking something is loose in my throttlebody wing nut

 

[Honcho]

Shawn that noise probably is your A/C pulley- it spins regardless of whether the A/C is actually on.

 

[captngaryr]

Shawn,
That sounds like my symptoms also. I don't hear it at idle so it's hard to locate.
Gary

 

[MarineNSX93]

https://www.youtube.com/watch?v=GTUVKPdeFxE

Maybe this is whats making the noise. Ugh I wish I can find it. Going to put the NSX on jack stands and figure it out once and for all and take care of it, Just hope the "whistling" is what I think it is.

 

[JoseJA1979]

mine makes the sound when the A/C is on also...its an annoying sound, very high pitch. I was told it was the A/C belt tensioner pulley so I changed it, still makes the sound when the A/C is on. If i run the climate control with A/C off at any fan speed it doesn't make the sound at all but that wont help on super hot days in the summer now will it.

 

[captngaryr]

Mine is a true whistle (a pure tone). It is not a screech, or a sound usually associated with friction or bearing noise (I think). It is RPM and engine LOAD sensitive. I'm wondering if is a small exhaust leak.

 

[MarineNSX93]

I got my car on jack stands and going all around putting my ear to different places and honestly I don't think it is the A/C system it sounds like its coming from somewhere in the core, i'm sure it air or something escaping form somewhere. This sucks.

 

[MarineNSX93]

Found out with some help from Jawn Naya that it is indeed a vacuum leak. Yay!

 

[shawn110975]

can you snap a pic of the vacuum hose you found was leaking? I am gonna check all mine since the vacumm hoses are 22 years old LOL everything else is new hose wise.

 

[davidf]

I think we'd all like to see that vacumn line for future reference.

 

[gt_nfr]

^ Agreed

 

[synergy004]

I would check the Orifice tube and change the O ring after oiling (evacuation of Freon first). This is also a sign pre-mature compressor failure in some cases and pressure build up releasing out of the culprit area. When that orifice tube gets gunked up with particles. This creates a sound described above. When the AC is on it will make a whistle like sound you can hear mainly outside. Very hard to pin point. If its your compressor bearing you would know its your compressor bearing. I am in the process of doing my AC complete update for maintenance prior to the meet in Dallas. What kicked this off on my end was my Trailblazer did the exact same thing which I corrected by evacuating the freon, changing the orifice tube o ring and recharging the system. I have not had that whistle come back as a result. I noticed quite a bit of build up in the tube as well. Hope that helps.

 

[gt_nfr]

[MENTION=7326]synergy004[/MENTION]; thanks for the info. Can you take a photo of this orifice tube?