No air conditioning blues

[RYU]

So it finally hit my NSX after at 5yrs. No cold AC again, but this time I think this might be a big job. So what's generally the common failure points these days?

I had it freon refilled last season so I'm pretty sure it's a leak somewhere as it's now all gone. Compressor still turns on. I have several new OEM parts on standby for this and my fear it's the evaporator.

What AC component has been going out for you guys lately?

 

[jeffreygebhart]

Watching this thread with interest! I have the same problem. Mine may not be as serious, just hoping that refilling it with freon every spring does the trick. Acura dealer service representative told me that they suspected that it was the evaporator and that it's an expensive, labor-intensive job.

 

[Honcho]

So it finally hit my NSX after at 5yrs. No cold AC again, but this time I think this might be a big job. So what's generally the common failure points these days?

I had it freon refilled last season so I'm pretty sure it's a leak somewhere as it's now all gone. Compressor still turns on. I have several new OEM parts on standby for this and my fear it's the evaporator.

What AC component has been going out for you guys lately?

On the older cars it is almost always the evaporator leaking. Pull your HVAC unit, ship it to Joe G. in Florida and get it back all refurbed (with a new evap) and re-foamed. Bad news is the dash has to come out. Also a good time to take apart your blower unit and clean it. Mine was nasty. I replaced the entire A/C system due to favorable access, but you only need to really replace the evap, compressor and drier as part of a refurb. If your condensers are shot-blasted, they might not be as efficient anymore, but if they're not leaking you don't need to replace them.

 

[Big McLargeHuge]

I've seen Kaz and others use fluorescent leak dye in the system to check where it's coming from, you can try that to pinpoint where it might be leaking from (might be multiple places). I've heard of leaks from the evaporator, rear refrigerant hose connections, compressor, loose Schrader valves for the L/H ports, etc. I'd disable the compressor if you don't have refrigerant so you don't damage anything by sending any metal through the system.

If you're already on R-134 it shouldn't be as painful as an R-12 car like mine still is. Seems like converting between the two brings up complications with the compressor part #'s.

You can check for leaks at the evaporator by taking off the front bay blower assy to see the front of the evap and any indicating dye.

Here's a link dump for threads I've been saving for when I go through this.

http://www.nsxprime.com/forum/showthread.php/202120-AC-Overhaul-advice-needed!
http://www.nsxprime.com/forum/showt...ith-a-94-or-newer/page2?p=1996629#post1996629
http://www.nsxprime.com/forum/showthread.php/160297-Some-help-needed-with-my-AC-DIY-repair
http://www.nsxcb.co.uk/entry.php?1318-Koyo-Rad-Cooling-Sys-Washer-motor-04&goto=next
http://www.nsxcb.co.uk/entry.php?1838-AC-Refresh-03&goto=next
http://www.nsxcb.co.uk/entry.php?1841-AC-Refresh-06&goto=next
http://www.nsxcb.co.uk/entry.php?1844-AC-Refresh-09&goto=next
https://www.youtube.com/watch?v=w1OWhnl76gU
https://www.youtube.com/watch?v=ga7aT63fkE4 (Joe's video)

 

[drew]

Unplug the compressor now. You do not want to deal with the "black death', which requires the cleaning of all the piping and that is one mother of a job.

With LUCK it is the evap and you only have to remove the dash (and rebuild the HVAC box).

You'll need a leak detector or dye in the system. I don't like dye because it never goes away and it is hard to tell old from new.

Fortunately, the diagnosis and repair tools are not that expensive (when compared to having a shop do the work), so this can be a pricey DIY instead of a normally extremely high priced repair...that will invariably break and or shortcut the repair.

You'll need: leak detector, gauges, and a vacuum pump.

Something like this should work well enough at least a few times: https://www.primetmall.com/products...s-ideal-for-food-packaging-milking-medical-et

 

[RYU]

Thanks so much everyone. Nsxprime ftw!

A friend has some leftover shrader valves as that was the cause of his leak. That's a super easy fix so I'm going to try that first. I do feel like I'm going to have to tear into the dash next... Boooo

 

[Valhalla]

Start simply and cheap and work your way up. Schrader valves are super easy and cheap. then try dye after you have added freon. Now go look for the leak. Mine was an expansion valve so I replaced that and the dryer. No problems since. Joe G. in Florida sells rebuild kits so you can do your blower, clean and update, at the same time. Best of luck.

 

[bogle]

FWIW, it’s curious that the compressor kicks on if there’s no Freon at all, the pressure switch should prevent running the compressor when no pressure.

 

[RYU]

I hope I found the culprit, but I fear this might have been too easy. Here's how I found the low side shrader valve. You can see all the dye fluid leaking out of the valve. It was barely hand tight.

I replaced it with the one on the left (red gasket)

 

[Big McLargeHuge]

Well that's at least one problem fixed, can you do a vacuum or pressure test with some manifold gauges to see if there's any other leaks before you refill with refrigerant? That was bogle's issues as well if I remember from his build thread.

 

[bogle]

Yeah my low side was loose also. I tightened it, got it refilled then it all leaked out at the compressor. Not sure if you’ve checked it already, but my compressor was (ahem, is) straight up oily and green.

Another tool in the toolbox is a black light flashlight. Looks like you have dye in there, so leaks will be bright green. Not sure where the evap leaks, but maybe you can crawl under the dash and shine the flashlight around to spot any leaks

 

[RYU]

I'm be doing a vacuum leak down test next at my local spot. I think it has to hold vacuum for some minutes (15?). It held vacuum 6 months ago so I have reason to suspect it ought to be this valve. When the vacuum machine is installed it effectively bypasses the valve by design so your valve could be bad and the leak down tool will never know it. Crossing my fingers.

 

[T38Flyer]

Start simply and cheap and work your way up. Schrader valves are super easy and cheap. then try dye after you have added freon. Now go look for the leak. Mine was an expansion valve so I replaced that and the dryer. No problems since. Joe G. in Florida sells rebuild kits so you can do your blower, clean and update, at the same time. Best of luck.

Does anyone have contact info for Joe G. In FL, for AC information?

 

[Valhalla]

He is on FB mostly. Joe Guttieri and he is in the usual NSX pages

 

[ch51670]

I just add a can of freon every summer and it usually lasts 6+ months. I'm not in the mood to spend a lot of money on the fix when I only drive the car 1500 miles a year.