AC compressor quit

[el toro]

on the freeway with the AC blasting in my 06 Mazda 5 when I heard something break with a snap followed by a long sigh. The AC quit working. A little while later, rasping whine from the engine like a loose belt.

The bearing on the AC pulley was toast. And the AC solenoid fuse blew. The compressor itself would not turn, but i was able to free it up by turning it backward. So I replaced the bearing on the compressor, a heck of a job in itself. But after that, AC would operate but not cool. Finally removed the compressor and took it apart.

Turns out the compressor is a vane type, with 3 vanes made of brittle sintered aluminum alloy ceramic. The vanes slide in an out of an eccentric shaft. Two of the 3 vanes were broken clean into two pieces each. No shards or burrs, just snapped in half like cookies.

Awaiting a new compressor for $530, will update after I install it.

 

[jmcglynn]

Curious... how many miles on your M-5?
I have to admit... I've always felt a bit uneasy about the A/C, with that characteristic "buzz" the compressor makes when it kicks on...

 

[el toro]

Just 70K miles. It would be easy to replace the vanes, but I could not find them online anywhere.

 

[Silentnoise713]

Looks like you already purchased a new compressor but you can check this site out for parts to rebuild your current compressor. I am no AC expert.
http://www.polarbearinc.com/pbpc/homepage/products_COparts.html

Give them a call. They are very good and helpful and might be able to get you a reman. compressor for cheaper. $530 for a compressor is crazy... Btw, did you catch who's the manufacturer?

 

[el toro]

Looks like you already purchased a new compressor but you can check this site out for parts to rebuild your current compressor. I am no AC expert.
http://www.polarbearinc.com/pbpc/homepage/products_COparts.html

Give them a call. They are very good and helpful and might be able to get you a reman. compressor for cheaper. $530 for a compressor is crazy... Btw, did you catch who's the manufacturer?

Thanks for the tip, I did buy the replacement pulley bearing from polarbear, stumbled upon them online. The compressor is OEM from Matsushita/Panasonic and I could not find a rebuild kit for it anywhere. Even the pulley bearing from polarbear was a nameless knockoff from China.

 

[j3nsmz5]

Whoa! Sounds like a terrible thing to happen. Mine just hit 70k miles. Is there a preventative maintenance for this or a way to check if mine is also on its way out?

 

[Silentnoise713]

Whoa! Sounds like a terrible thing to happen. Mine just hit 70k miles. Is there a preventative maintenance for this or a way to check if mine is also on its way out?

I read a bit into R12 systems when my Miata's died. In short, the best (and only?) preventative maintenance you can do is to turn on the AC every now and then and not let it sit for too long without operation. The system needs to cycle to move the freon and oils to lubricate itself, sorta speak. I would think this applies to R134a systems as well as it is still freon and oil base (different types). Would like to hear what el toro has to add as he seems to know AC systems well.

@ el toro, polar bear can't find a reman compressor for you?

 

[el toro]

Whoa! Sounds like a terrible thing to happen. Mine just hit 70k miles. Is there a preventative maintenance for this or a way to check if mine is also on its way out?

I believe my problem was caused by a pulley bearing gone bad, causing clutch chatter, like turning the A/C on and off many times a sec. The bearing is low profile, 32x47x18, so its prob at the top of its load range. You can check for a bad bearing by rocking the A/C compressor pulley axially on its shaft to see if it moves. The belt is under tension so this will require some heft. Judging by the posts on mazda 3 forums, bearing failure is not uncommon for this compressor model. This video on youtube is instructive of the problem and the unique raspy sound of the bad AC bearing http://www.youtube.com/watch?v=w5wWGRlO-98

@Silentnoise713 No reman replacement on polarbear. I found a reman one on eBay for ~350, and used ones from a junkyard for 200 plus shipping. I opted to pay the extra 200 for the new OEM since the work involved in installing and recharging the system is substantial. If the new one runs for another 70K miles, it is money well spent.

 

[Davicho]

Correct me if I am wrong but in my opinion one of the reasons there is that many compressor failures is the fact of where it is located. It is at the very bottom of the engine which makes it easier to get to but also makes it exposed to al the elements much easier as well as susceptible to damage, the only shield it has is the built in small metal plate and the lower plastic engine splash shield. JMO

 

[el toro]

Correct me if I am wrong but in my opinion one of the reasons there is that many compressor failures is the fact of where it is located. It is at the very bottom of the engine which makes it easier to get to but also makes it exposed to al the elements much easier as well as susceptible to damage, the only shield it has is the built in small metal plate and the lower plastic engine splash shield. JMO

Very true, although well designed bearings such as wheel bearings live long under similar conditions. Appears AutoZone also carries the a/c bearing
http://www.autozone.com/autozone/pa...91td3?itemIdentifier=946328&_requestid=837083

 

[el toro]

Success!

Today I installed the new AC compressor from Mazda.
Took me an hour to take the old one out and put the new one in. The new compressor came with 4oz oil and I did not take any out since rotary vane compressors are only weakly sensitive to oil charge.

Then I used a https://www.amazon.com/dp/ (commissions earned) to evacuate the system.
I let the vacuum pump run for 1.5 hours. The vacuum pressure did not change after the first 15 minutes, but I wanted to remove moisture from the system. Contrary to the popular viewpoint of replacing the receiver/dryer, running the vacuum pump removes moisture from the system as low pressure lowers the boiling point of water. Then I shut off the valves on my https://www.amazon.com/dp/ (commissions earned), switched off the pump and waited half hour to make sure the system held vacuum without leaks. After confirming no leaks, I recharged the system with R134A. I used a 510g canister for the purpose, as the recommended charge is ~500g. With the engine off, I got an initial charge in so that the pressure limiting switch would not suppress the compressor. Then, I started the engine and ran the AC full blast while charging the rest of the canister into the low pressure side. When complete, the manifold gauge cycled between 25-35psi on the low side and 150psi on the high side.

The job cost me $700 for parts and tools, which is painful for a vehicle worth $8K, but the dealer wanted over $1500 plus taxes and the AC is a must have for driving the kiddies around. Satisfied, I drove off to the gym with cold air blasting from the AC...

 

[speed5]

my compressor clutch also has a bearing failure. rattling noise sounds like a diesel engine, when a/c is off. less noise with clutch engaged. my 5 has 89k miles. gonna have local shop swap in new compressor/clutch assembly. no time to do it myself. had to replace my alternator a month ago. The internal voltage regulator went bad and killed my battery which i replaced with an Optima Red Top. last week i had to replace front crash sensor for the airbag system. one of the sensor contact pins corroded away which caused airbag light to blink constantly. i just hope nothing else breaks for a while. just made my last payment.