AC problems

[Jett]

My AC makes a moaning noise when the compressor is engaged. The noise gets louder when I accelerate (ie, the engine is turning faster). When the climate control system is off, or when I manually turn off the compressor (AC on/off button) the noise stops. I take this to mean that the AC compressor/clutch need to be replaced, but I wanted to ask before I started accumulating parts. The compressor isn't seized (yet) so I am hoping that the system isn't contaminated.

I read several threads that discussed leaking evaporators, etc. but wanted to toss this problem out for comment.

Any input?

 

[NSXFRIEND]

Here is how to test your climate control functions if you are not aware already. Hope this helps.

 

[Jett]

Thanks for the pics to the climate control diagnostic. I fairly recently had my climate control rebuilt by a reputable tech (Briank). The problem isn't in the climate control unit itself.

I went into the engine bay and observed the operation of the clutch. There was no evidence of belt wear, and the clutch engaged properly when the climate control was was turned on, and released properly when the AC was turned off (AC on/off button on climate control). Externally everything appeared normal.

At this point I am planning to have the system tested to see if it will hold pressure and, if so, having the system recharged with refrigerant to see what that does.

 

[Jett]

Had the AC system recharged yesterday; it was low on refrigerant with .6 lbs remaining, but the system held a vacuum. They added dye to the system for leak detection. After the recharge the AC blows ice cold and the moaning went away. Will watch to see how quickly the refrigerant leaks back down.

Hopefully this is all I needed.

 

[Jett]

The moaning came back with a vengeance today. :frown:

It is really loud when accelerating. I also think I detect a hint of sound like that which failing bearings might make when they spin. At this point I think it is the compressor.

I see a visit to the Car Doctor in Falls Church, VA in my future.

 

[racerx24]

Mine did that for a little while before the compressor seized up and then comes the smell of belt burning. Oh yeah and when you lift off the throttle the engine stalls. New a/c compressor install coming up soon. Good luck. Hope your problem is not the same but doesn’t sound hopeful.

Frank

 

[Jett]

You know now that you mention that I think I have already smelled a faint burning smell like three times. It smelled like burning wires, but I couldn't figure out where it was coming from. Now I think I know.:frown:

I had ordered a "new" compressor and receiver/drier which showed up today - now just need to find time to get it installed.

 

[Jett]

Okay, finally got the new "NEW" compressor and receiver/drier installed at the Car Doctor (Falls Church, VA) today. The old compressor wasn't seized so the system wasn't contaminated. The tech chose to keep the Integra pulley instead of replacing it with the old pulley, as he said the pulley was integral to the clutch and he didn't want to put an old clutch on a new compressor (makes sense to me). So he kept the Integra clutch/pulley and installed a different size belt. He also indicated that the receiver/drier was a little larger in diameter (supposedly this is fairly common) but that he was able to install it without difficulty.

Although I haven't picked up the car yet, I spoke with their NSX tech and he said that overall the compressor replacement was pretty straightforward with no extraordinary problems. Still, it was a time-consuming process and probably took 5-6 hours of labor, to include evacuating and recharging the system. (I will edit this post when I pick up the car to sharpen and correct the details)

Cost today was $708 for labor/supplies/etc. So with the cost of the compressor and receiver/drier, plus a rental car for one day, the total cost to me for the compressor replacement came to approximately $1000.

 

[LJSB]

Okay, finally got the new "NEW" compressor and receiver/drier installed at the Car Doctor (Falls Church, VA) today. The old compressor wasn't seized so the system wasn't contaminated and therefore didn't cause undue problems. The tech chose to keep the Integra pulley instead of replacing it with the old pulley, as he said the pulley was integral to the clutch and he didn't want to put an old clutch on a new compressor (makes sense to me). So he kept the Integra clutch/pulley and installed a different size belt. He also indicated that the receiver/drier was a little larger in diameter (supposedly this is fairly common) but that he was able to install it without difficulty.

Although I haven't picked up the car yet, I spoke with their NSX tech and he said that overall the compressor replacement was pretty straightforward with no extraordinary problems. Still, it was a time-consuming process and probably took 5-6 hours of labor, to include evacuating and recharging the system. (I will edit this post when I pick up the car to sharpen and correct the details)

Cost today was $708 for labor/supplies/etc. So with the cost of the compressor and receiver/drier, plus a rental car for one day, the total cost to me for the compressor replacement came to approximately $1000.

5-6 hours sounds like a lot of labor for a compressor and drier swap on a NSX even with a recover,evacuate/recharge.

 

[Jett]

Okay, picked up the car this morning. Here is where I sharpen the details...

The system was thoroughly "pre-checked" (dye was added when I had the system charged several weeks ago) for leaks (none found). The system was found to hold vacuum. The electrical circuit was checked for proper voltage per oem specs. Excess lubricant was manually removed from the system (by turning the compressor shaft) after installation. System was evacuated for a full hour, then recharged with R134a. AC belt was replaced with different size belt to accomodate Integra pulley.

Total cost breakdown:

$212 - Compressor, receiver/drier, and shipping.
$598 - "A/C Service" (labor)
$ 36 - 1.8 lbs R134a
$ 18 - Dye
$ 17 - A/C belt

Grand Total = $881

The total cost seems very reasonable to me. This was the least expensive route available to me in my area, within the limits of finding someone who was qualified to work on the NSX. While not exactly cheap, any other route involving new parts would have been even more expensive, plus after a very thorough discussion with the tech I am satisfied that a completely professional job was performed during the installation. The physical replacement of the compressor is more difficult on the NSX as the compressor is in a relatively difficult to access area and a crossmember needs to be removed to facilitate compressor removal.

A/C now working fine. Will see how it performs over the longer term.

 

[LJSB]

30lb container of 134a locally is a little high right now at $150.00.
Your shop has a 300% mark up on this.

The labor for the compressor and drier combined is 3.1 hours in my book.
1.8 recover and recharge labor.

If you're happy and it's working great, that's what matters most.