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Air Evaporator Failures--common??survey

30 September 2000
valrico, fl
How many have had evaporator replaced? I am on my 5th in 5 years on my 92 with 71K miles. Two days after Ferman Acura, Tampa replaced latest evaporator, the compressor siezed! Acura Customer Service has responded that it must be the dealer's fault and will not give any goodwill......Ferman says now way did they cause compressor failure--I just keep paying. Please let me know if you or you know of any NSX A/C evap failures--I have had 5 responses thus far. Thanks

[This message has been edited by Joe Gliksman (edited 06 October 2000).]

[This message has been edited by Joe Gliksman (edited 06 October 2000).]

You should check and see what part of the coil is leaking. If you keep getting pin holes in the outer radius bends, you should write Acura a letter. Mine also failed ('91, original owner, about 25k miles at failure about two years ago) so I pulled it myself to see why. When I found that the coil was in no way worn from contact (rubbing) and that the protective coating was still in as new condition, and that the pin holes were ONLY in the outer radius bends (where the aluminum is stretched to turn 180 degrees), I decided it was time to write Acura.

I've heard some say electrolysis causes the aluminum to weaken, but I'm inclined to believe several temperature cycles continue to expand and contract the coil until it fails at its weakest point (the outer radius bends). My degree is in engineering, so it may be fair to say I understand thermodynamics and assembly processes. I told Acura that I was reluctant to install another e-coil when it appeared to me that without a design change, I was going to see another failure. They comped me another e-coil, but I had to do all of the labor (about ten hours the first time). As strict as the EPA is, it might be in everyone's best interest to have them apply some pressure on Acura so that they can then apply some pressure on Showa, the e-coil manufacturer. When (if) mine fails again, you can be sure I'll go that route.

I wonder if most of the failures can be localized to warmer climates. Ken's '91 has never had a problem, but he lives in Chicago. Safe to say his AC has not been cycled nearly as many times as mine down here in Texas.

If you write Acura a letter, be nice. The problem is with Showa. BTW, other Showa e-coils on other Acura models are also failing.

FYI, Showa also makes the front forks for Honda motorcycles as well as the rear shocks. When I raced dirt bikes, the big dilemma was, get the Honda for the motor and send the Showa shocks off to be rebuilt or buy the Kawasaki for the suspension (Kayaba) and send the motor off to be rebuilt. If you follow 600 cc supersport motorcycle racing you will know that the factory Honda riders, running the Works Showa suspension, were being outdone by the privateer Honda teams running the Ohlin suspension. It appears Showa needs to hire a couple really good engineers. Did I say that?
Showa has been manufacturing this defective evap coil for 15 years, what makes you think they'll do anything about it AFTER the car has been discontinued?

I had a slow leak when I bought my 1991 car in 1996 with 20k miles. Finally replaced the evap and no problems in 2 years and 10k miles. Multiple failures indicate a possible environmental problem. Also, are you remembering to turn off the AC 5 minutes before stopping the car to avoid condensation on the evap?
The reason for doing that is to prevent mold from forming which will cause the HVAC to smell funky. Not to prevent failure of the evap. which seems to be a 91-92 problem for the most part.
That is good news, since I have never had one last long enough to grow mold--but I hope since I did the last one myself, it will go longer--maybe I need to start shutting it down early!
Non-owner, been lurking off and on for a few months (tried to buy one recently--I'll probably post the story someday soon).
Just curious how you guys know if your evaporators are leaking, and not something else? If it takes 15 hours to replace the evap, I would think they're too buried to get a sniffer on them for a quick diagnosis? Again, I'm a complete NSX noob, and I don't know how the layout is different, but most cars' evaps are not accessible to determine leakage with a sniffer or with UV dye.
From a small sampling, I'm inclined to think that just about every car on the road leaks, even brand new ones. They usually just leak tiny, tiny amounts. On the order of grams/year.
Regarding the original post from 2000, I'd bet the shop either didn't measure/replenish the oil in the system or that they used the wrong kind of oil.
I'm bummed to hear about how big a problem this is. There are probably millions of heaps of junk rusting away in yards across the country, decades old, but with working A/C systems!
no evaporator replacements but i have had my a/c compressor replaced twice within 18 months of each other.
Daedalus said:
If it takes 15 hours to replace the evap, I would think they're too buried to get a sniffer on them for a quick diagnosis?

A sniffer at the center vent will usually beep. Also you can often see dye if you remove the blower (forward of the bulkhead).
I had mine replaced about 4 years ago (on a '91). The mechanic I had working on it wasn't very good with NSX's (I know now), so I'm not sure it needed it. I do know that the condensers were damaged at the time, which he didn't find, but I found later, after insurance wouldn't pay. :frown: Shortly after, I also had to replace the compressor. So this doesn't really answer your question, since it's unclear what caused what.... :eek:
Florida and Texas. It appears that the expansion and contration is causing the pin holes.

I have 76k, live in central cali, where we don't need airconditioning, and I still blow snow:biggrin:
My a/c system lost all its freon.

I pulled the heater blower assembly and ran a R-12 sniffer all around the evaporator. Most of the sniffing is "blind" so I really can't see if I'm getting a false reading from the sensor tip touching the sides or maybe from insulation.

I've attached a photo of my new evap as a guide to what I'm sensing. The yellow ellipse indicates moderate response from my sniffer and the red ellipse indicates max sniffer response.

('prime seems unable to upload an image right now. But I'm getting a sniffer response along the bottom of the entire evap, prolly due to R12 settling. And a max hit along the driver side along the deep elbow bend below where it attaches to the firewall).

Can anybody tell me if this is consistent with NSX evap failure?

I'd like not to inject dye into the system if I can help it.

Any help appreciated

/it is my duty to recycle an old threads
'91 X, driven in hot/humid climate for 14 years, finally replaced the evaporator. 12 months after replaced the compressor.. I find the life of these parts to be above expectations as we usually have the a/c on 9 months in a year. Labor/parts totaled US$2500 but not at the authorised dealer who would be charging at least 50% more and have to wait 4/6 weeks for parts.