a/c woes in a 91

[Cincinnati Scott]

Hi everyone,
I don't drive my 1991 NSX all that often (55k miles), so I rarely use the a/c. Well, a few weeks ago, I decided to drive it out in the heat and noticed a couple things: 1) it didn't cool very much and 2) the compressor made a gawd awful noise.

So, I looked at the sight light and determined I needed freon. At the same time, I did the retro-kit converting it to R134a. I thought that maybe by adding the oil to the compressor that it might quiet it down. Well, I was wrong :frown:

Now I have two problems...a "fan whirring" noise coming from the compressor when it's running and now a new one, where there's a loud buzzing seemingly coming from the front right of the passenger compartment.

Questions:
1) Is my compressor cooked?
2) Could it just be the idler pulley?
3) What the hell is that noise in the front? (I can make it do it and stop with turning the compressor on and off -- it is NOT fan speed related)

Any ideas?

Thanks,
Scott

 

[Briank]

#3 sounds like the expansion valve making noise. Did you have the system properly evac'ed and recharged with 134a or did you just add it

 

[Cincinnati Scott]

#3 sounds like the expansion valve making noise. Did you have the system properly evac'ed and recharged with 134a or did you just add it

Yep, I had the system evac'd because it was R12...could it be the valve is bad?

 

[Briank]

From my limited experience noisy expansion valves need to be replaced to solve the problem. But with your compressor being questionable it may just be reacting to that or the compressor is dumping debris as it dies which could also be why the expansion valve is having a problem. Did you replace the receiver/dryer?

 

[Cincinnati Scott]

From my limited experience noisy expansion valves need to be replaced to solve the problem. But with your compressor being questionable it may just be reacting to that or the compressor is dumping debris as it dies which could also be why the expansion valve is having a problem. Did you replace the receiver/dryer?

I've replaced nothing at this point...I'm thinking the compressor is hosed at this point. But the parts are expensive, I'd rather not just replace things until it starts behaving.

 

[drew]

Didn't we already go over this?

Oh yes, you were warned (here)
http://www.nsxprime.com/forums/showthread.php?t=73849

A very similar post:
http://www.nsxprime.com/forums/showthread.php?t=49982

But the parts are expensive, I'd rather not just replace things until it starts behaving.

You are (WERE) in the high hundreds...

Stop using it (now) and diagnose or the damage will rise to several thousand dollars very quick (though it sounds like you might be there already).

If the compressor grenaded: you are going to have to replace it and you will have to flush the entire system as well. A world of hurt, but you can use it replace all the o-rings as you methodically flush the system.

It doesn't take much to gunk up the expansion valve. Even though it is a back breaker, the expansion valve can be replaced with the evaporator in the car.

 

[Cincinnati Scott]

Didn't we already go over this?

Oh yes, you were warned (here)
http://www.nsxprime.com/forums/showthread.php?t=73849

A very similar post:
http://www.nsxprime.com/forums/showthread.php?t=49982



You are (WERE) in the high hundreds...

Stop using it (now) and diagnose or the damage will rise to several thousand dollars very quick (though it sounds like you might be there already).

If the compressor grenaded: you are going to have to replace it and you will have to flush the entire system as well. A world of hurt, but you can use it replace all the o-rings methodically go though the entire system.

It doesn't take much to gunk up the expansion valve. Even though it is a back breaker, the expansion valve can be replace with the evaporator in the car.

Like I said, I rarely drive the car, so it's no worse than it was before trying to see if oiling it fixed the issue. The compressor *does work*, so I don't think we've gotten into catastrophe mode just yet.

I'll start with the compressor and see where that takes me.

 

[davidf]

If you can find it, stick with the R12 if poss. 134 is hard on old orings since it operates at a higher pressure. My.02.