A/C Compressor Disturbing Failure

[DBMaster]

Well, my 11 year old Denso compressor gave up yesterday in the 103 degree heat. It had been squeaking and making noises for years, but over the last couple of years it had developed a leak at the shaft. After just a couple of incidents of blowing warm and then cold it seized and melted the belt. I parked after a highway jaunt and smoke was literally billowing out from the engine bay. I guess it's good that I didn't get the compressor in advance because Danny at Danny's Import Service told me that remans and aftermarket units just don't last. I know about the remans from prior experience. He actually asked me if I wanted to supply the parts because for him availability is limited and parts are pricey. I got a new Denso unit and receiver/drier from Rock Auto and with next-day delivery the parts were $410. That knocked a couple hundred bucks off the job. Though I do have three cans of R12 I am going to let him use Freeze 12. After much experimentation they have found that to be the best replacement refrigerant for these cars, plus it's readily available and it can use the existing oil. If I used up my last three cans of R12 I wouldn't have anything left for top-offs. I'm in a rental right now. I like renting cheap cars because even the newest low end cars don't hold a candle to ours in ride quality and handling. It guarantees that I am always happy to get my antique back. I guess I just can't part with the thing.

[Pnem3]

I think you are going to be very happy with the Freeze 12. Good luck.

[Dr_Snooz]

You're about due for the routine replacement of all A/C parts. It seems like Honda A/Cs just kinda crap out completely at about the 10 year mark. Replace everything and you'll have another trouble-free 10 years. Good luck with the job.

[DBMaster]

You're about due for the routine replacement of all A/C parts. It seems like Honda A/Cs just kinda crap out completely at about the 10 year mark. Replace everything and you'll have another trouble-free 10 years. Good luck with the job.

Sure seems to be the case. If I had the time I wold try to adapt a more robust compressor because the Keihin is an eight year device and I guess the Denso is a ten year device. The Frigidaire A6 in my Pontiac was at eighteen years when I sold the car. It would blow air out at 31 degrees whereas my Honda does 45 degrees on a hot day, maybe 40 under just the right conditions. Danny told me this is what Honda calls "good" performance from an A/C system. Oh, well.

[LX-incredible]

The pontiac uses an orifice tube so the system is more "tunable" depending on the charge. Expansion valves will continually vary flow, controlling evaporator temp. Less or no insulation around the valve bulb and evaporator outlet can result in lower temps, depending on system condition...

[DBMaster]

The Pontiac I mentioned is a 1972 Catalina. It had something called a POA valve rather than an expansion valve - as you mentioned. When the car was around twelve years old one of the hoses sprung a leak. I went ahead and replaced all of them and never had to add Freon again after that. Of course, the compressor itself was about half the size of the whole engine in the Accord. Unlike the compressors that came later, the one in the '72 ran continuously once engaged. I think that has a lot to do with the longevity when compared to one like ours that cycles on and off frequently.

[Dr_Snooz]

Sure seems to be the case. If I had the time I wold try to adapt a more robust compressor because the Keihin is an eight year device and I guess the Denso is a ten year device. The Frigidaire A6 in my Pontiac was at eighteen years when I sold the car. It would blow air out at 31 degrees whereas my Honda does 45 degrees on a hot day, maybe 40 under just the right conditions. Danny told me this is what Honda calls "good" performance from an A/C system. Oh, well.

Sounds about right. GM air conditioners are freakin awesome. You can't beat them with a stick. Honda A/Cs aren't quite as great, but they'll be good enough to keep you from rolling down the windows most of the time LOL.

[LX-incredible]

Interesting. I've never worked on anything with a POA valve. It seems that they work by maintaining constant pressures by bleeding off the high side.

[LX-incredible]

Sounds about right. GM air conditioners are freakin awesome. You can't beat them with a stick. Honda A/Cs aren't quite as great, but they'll be good enough to keep you from rolling down the windows most of the time LOL.

Yeah, I've got a dual-air suburban with the A6 which I replaced the compressor and what not on 6 years ago. The sucker still blows cold, even with the R134a. Properly done R12 systems on these accords are quite nice though.

[DBMaster]

Don't get me wrong, the A/C in the Accord is fine. I drove the Pontiac for ten years and I've been driving the Accord for 21 so, I guess Honda air is what I'm really accustomed to. Yes, LX-inc, I do recall from my old Pontiac shop manual that the POA valve uses a constant flow rather than "bursts" like the expansion valve. When the Catalina was about 16 years old the compressor pulley bearing seized. It melted and broke the belt. I took it to an A/C shop and they replaced the clutch assembly while the compressor was still on the car. No refrigerant loss, new belt, and I was back down the road in "the refrigerator." There's just something about being able to see your breath in the car when it's 100 degrees outside that makes me smile.

[2oodoor]

i hated the poa valve systems, but on a lighter note did you ever see the evaporator coil on that ponitac, wholly dr freeze bluntman. A quality made piece too btw, not exactly what you see now days.

[ecogabriel]

Well, my 11 year old Denso compressor gave up yesterday in the 103 degree heat. It had been squeaking and making noises for years, but over the last couple of years it had developed a leak at the shaft.

Though I do have three cans of R12 I am going to let him use Freeze 12. After much experimentation they have found that to be the best replacement refrigerant for these cars, plus it's readily available and it can use the existing oil. If I used up my last three cans of R12 I wouldn't have anything left for top-offs.

I got two cans from ebay so I could recharge the A/C in the civic and use the remainder to top off the Accord. It is not cheap but one still can get hold of those...


If I had the time I wold try to adapt a more robust compressor because the Keihin is an eight year device and I guess the Denso is a ten year device.

I saw a 3G in the junkyard with a SANDEN compressor installed. Though I do not remember many details the hoses were custom made (not ghetto or anything they looked right down to the connectors but the way they were arranged was not the one in the OE arrangement. I know it was a sanden compressor because of the label pointing upwards so I could see the brand (can't remember model but it was most likely a 5xx (507?).
I don't know what bracket it used but I would bet one without too much modification.
I remember it because someone was hunting for a compressor for a 3G and I had just seen that so I pointed it out but the guy wanted a Keihin... That would be a research topic for an expert... I am sorry for not being more specific

Oh, if you have not repaired it yet may I suggest you check the evaporator trying to clean it? Even after recharge I was hot in the Civic. Air was cold but the airflow was strangely weak.
I managed to half-open the plastic covers in the evaporator to take a look inside: I removed a jungle of leaves, seeds, and whatnot. The worst part was the evaporator covered in a wet, compact blanket of dirt, dust and lint. I could hardly remove 1/3 of it; maybe compressed air would have cut it but I don't have an air compressor and it would have been difficult to reach the depths of the evaporator box anyway. Still, now enough air flows for the A/C to do a more decent job. Now I can feel some cold air on my chest when driving...

My 0.002

[DBMaster]

I recall a post with a photo of such a dirty evaporator. Was that your post? The airflow is still quite strong, though, one of these days I would like to get in and clean the thing. The job's all done and I picked up the car yesterday. With labor, parts (provided by me), shipping, and car rental for two days my wallet is now $800 lighter. The labor and refrigerant came to about $240 so really not that bad. I do recall talking with an auto A/C shop in 1999, when my Keihin compressor needed replacement. They said that they adapt a Sanden compressor to fit. Maybe you were seeing one of those kids of jobs. I ended up going with the $750 kit from Honda that converted to the Denso compressor. It came with the compressor, hoses, belt, bracket, and drier. So, this time around, all I had to do was order a new, non-reman, Denso compressor for $300 from Rock Auto.

[w261w261]

I'm on my original compressor @ 228k miles, but I live up north. When I got the car in '01, I recharged it. Topped it off about 5 years ago, and then 1/2 lb about 2 years ago. That's it. Blows cold.

[DBMaster]

You are doing unusually well, then. Pretty much all the failures seem to be related to the cycling on and off. It eventually wears out the clutch or causes leaks at the shaft seal. I know that GM went to that cycling type of compressor around 1980 and after that the A/C system just never lasted like it did on the older cars. I just have to live with the fact that ten years is about as long as they last down here. Remember, in Texas the A/C compressor will be running higher average head pressures than in the Northeast. I'm not saying it doesn't get hot there. It just doesn't get as hot for as long as it does here. Plus, I like it cool so I run my A/C for about 8-9 months out of the year! :)

[ecogabriel]

I recall a post with a photo of such a dirty evaporator. Was that your post? The airflow is still quite strong, though, one of these days I would like to get in and clean the thing. The job's all done and I picked up the car yesterday. With labor, parts (provided by me), shipping, and car rental for two days my wallet is now $800 lighter. The labor and refrigerant came to about $240 so really not that bad. I do recall talking with an auto A/C shop in 1999, when my Keihin compressor needed replacement. They said that they adapt a Sanden compressor to fit. Maybe you were seeing one of those kids of jobs. I ended up going with the $750 kit from Honda that converted to the Denso compressor. It came with the compressor, hoses, belt, bracket, and drier. So, this time around, all I had to do was order a new, non-reman, Denso compressor for $300 from Rock Auto.

No, it was not mine. I can't take it apart for cleaning it as I have just charged it; I'll try with other means

As for the sanden "conversion" I bet it was a "507" compressor ... As I said I was not looking into those details; it just caught my attention the kind of disparate hose arrangement...

My wallet would have been quite light too :rant: But 90+/100s weather does not understand finances.. :barf: Overall, you got your A/C back and that's good. How does it work with Freeze12?

[DBMaster]

I've got to take my thermometer tomorrow and verify, but it feels pretty much the same as the R12 did and it was over 100 today. It stayed cold in traffic. Just like before except without the embarrassing noise and smoke coming from under the hood. :)

[nfs480]

So far i've had my reman keihin that I got off ebay for $117 installed for three months now and so far so good. I got 20 years out of the first keihin, so maybe i'll get lucky again.

[DBMaster]

Perhaps you will be lucky. I have only installed reman GM conpressors in the past. These were 10-15 year compressors when new and the remans lasted three. I pretty much only go new. My mechanic echoed that when he said that the remans (and, even new aftermarket units) lasted for a year. It's all a matter of how well the rebuild was done and what was wrong with the compressor that was rebuilt. twenty years out of a Keihin is pretty darned impressive!

[DBMaster]

I measured the vent temp this morning on the 20 mile drive to work. It stayed consistently in the 43-45 range. I'll check again this afternoon when it's over 100 to see if it can maintain a good output. The best I ever got out of the system with R-12 was around 40 on a spring day so it does appear that this is equivalent. Danny said they like Freeze 12 because it works with the existing mineral oil (carries it through the system) and it maintains head pressures similar, or slightly lower than R-12. One of the problems with R134A in our systems is the higher head pressure that reduces the life of the whole system. The drier that came with the Honda/Denso kit in 1999 did not have a sight glass, but the one I have now does, though, most of the time you do not charge with enough alternative refrigerant to actually clear the glass. I know if you clear the glass with R134A you have overcharged it. I always pretty much charged to a specific pressure once the vent temp bottomed out.

[ecogabriel]

Sounds pretty good; if the compressor cycles then it is reaching the preset temperature to prevent ice formation. I wonder if that switch can be adjusted a couple of degrees lower...

[LX-incredible]

^ It can indeed be adjusted, or replaced with another ranco or similar thermostat with an adjustment knob.