Air conditioning issue
08-24-13, 01:31 PM
#1
Junior Member
Thread Starter
Join Date: May 2012
Posts: 20
Likes: 0
Received 0 Likes
on
0 Posts
Air conditioning issue
After a hot and rainy summer in SC - it's time to fix my AC. I've been working on diagnosing the issue and combing the forums for fixes and solves. Unfortunately I'm not sure whether the issues lie within the ECU or somewhere else. I've taken some videos to explain the problem. Thanks for any insights and help you guys can provide.
First, I performed the PowerFC A/C Fix that is well documented in the forums. Where I originally was just getting the A/C to click on in modes 1,2 and 3 - it will not click on in all 4 speeds when I first crank and test it in the garage.
At this point, I thought I had it solved. Unfortunately, when I took it out for a test drive - it is not fixed. So here is what's happening.
1. When I crank the car and let it warm for 5 mins or so - the A/C will click on and perform as expected.
2. I will take it out and start driving it and will work for the first 100-200 yards usually. Then, the engine will DEFINITELY feel the load and start jolting as the A/C compressor tries to turn on. I will also hear a knocking sound underneath the glove compartment where I assume the A/C Cooler is located. I've documented the knocking sound in this video.
If you listen to the video, you will hear the knocking. Also, I can feel something "moving" within the box. Not sure what it is.
3. Again, after driving the car a little bit - the compressor does not seem to be able to react properly. Sometimes, the compressor will try to kick on while idling and actually stall the car out. This happens pretty regularly. Here are two videos of the compressor trying to kick on after driving the car a block. You can hear the high pitch noise when it tries to turn on.
Now as you can see, it tries to kick on and sometimes will eventually do it.. but this will only ever happen when idling. When I am driving, it will essentially do the knocking while driving and try to kick the compressor on with no luck.
As a side note - I've owned this car about 2 months now. Still trying to learn when the previous owner has done. He did install a Power FC ECU and I do not have the Power FC Commander (thinking I might need to buy it). I don't know if he's monkey'd with the settings and the engine just doesn't have enough to keep the compressor on or what. I've also see that it could be a relay issue somewhere within the wiring.
Would love it if anyone has some ideas. Willing to try most things to see if I can get it working.
Thanks to all!
First, I performed the PowerFC A/C Fix that is well documented in the forums. Where I originally was just getting the A/C to click on in modes 1,2 and 3 - it will not click on in all 4 speeds when I first crank and test it in the garage.
At this point, I thought I had it solved. Unfortunately, when I took it out for a test drive - it is not fixed. So here is what's happening.
1. When I crank the car and let it warm for 5 mins or so - the A/C will click on and perform as expected.
2. I will take it out and start driving it and will work for the first 100-200 yards usually. Then, the engine will DEFINITELY feel the load and start jolting as the A/C compressor tries to turn on. I will also hear a knocking sound underneath the glove compartment where I assume the A/C Cooler is located. I've documented the knocking sound in this video.
3. Again, after driving the car a little bit - the compressor does not seem to be able to react properly. Sometimes, the compressor will try to kick on while idling and actually stall the car out. This happens pretty regularly. Here are two videos of the compressor trying to kick on after driving the car a block. You can hear the high pitch noise when it tries to turn on.
Now as you can see, it tries to kick on and sometimes will eventually do it.. but this will only ever happen when idling. When I am driving, it will essentially do the knocking while driving and try to kick the compressor on with no luck.
As a side note - I've owned this car about 2 months now. Still trying to learn when the previous owner has done. He did install a Power FC ECU and I do not have the Power FC Commander (thinking I might need to buy it). I don't know if he's monkey'd with the settings and the engine just doesn't have enough to keep the compressor on or what. I've also see that it could be a relay issue somewhere within the wiring.
Would love it if anyone has some ideas. Willing to try most things to see if I can get it working.
Thanks to all!
08-25-13, 08:37 AM
#4
Full Member
iTrader: (1)
Join Date: Mar 2001
Location: Gainesville, GA USA
Posts: 241
Likes: 0
Received 0 Likes
on
0 Posts
I would have the charge pulled and recharge it with a known quantity. Sounds like somebody got a few cans of "fix it urself" and put them in without regard to the proper charge level. If there is too much freon, it may be compressing into a liquid IN the compressor, which will destroy it. It may be cycling due to a high pressure switch, but I don't have a schematic of the system in front of me.
If that's not the case, I'd say the compressor is about to die.
If that's not the case, I'd say the compressor is about to die.
08-25-13, 08:02 PM
#5
Could be slugging of the compressor by liquid refrigerant and/or oil. Possibly a severe overcharge of refrigerant and/or oil. I suppose the expansion valve could be wide open as well which might result in flood back (of liquid refrigerant) to the compressor.
In any event, a check of system pressures would help your diagnosis. As was suggested by a prior poster, you could evac and recharge; however, you still may not know what's going on with the oil in the system unless you drain the receiver and compressor and normalize.
Again, slugging of the compressor with a liquid can damage it, so I would avoid its operation until you sort it out.
In any event, a check of system pressures would help your diagnosis. As was suggested by a prior poster, you could evac and recharge; however, you still may not know what's going on with the oil in the system unless you drain the receiver and compressor and normalize.
Again, slugging of the compressor with a liquid can damage it, so I would avoid its operation until you sort it out.
08-26-13, 10:40 AM
#6
Senior Member
iTrader: (1)
Join Date: May 2002
Location: Houston, TX
Posts: 705
Likes: 0
Received 0 Likes
on
0 Posts
That compressor sounds woefully unhappy.
If the compressor were getting slugged with liquid refrigerant, then there should be frost on the line leading to the compressor since there would still be liquid refrigerant in that pipe boiling off and absorbing heat.
That having been said, the TV14C compressor that Mazda put on these cars actually has internal bypass valves that will allow non compressible materials to be ejected from the vane chamber into the rear housing of the compressor, sparing it from damage.
With the engine off, grab the center hub of the compressor and spit it by hand clockwise. Describe how it feels when you turn it....
If this were my car, and I wanted long term reliable A/C I'd tear the whole system out of the car, flush the heat exchangers and piping to bare metal, replace the expansion valve, drier, compressor and all o-rings. There's no telling what has been done to it over the years, how much and what type of oil is in the system, etc etc.
If the compressor were getting slugged with liquid refrigerant, then there should be frost on the line leading to the compressor since there would still be liquid refrigerant in that pipe boiling off and absorbing heat.
That having been said, the TV14C compressor that Mazda put on these cars actually has internal bypass valves that will allow non compressible materials to be ejected from the vane chamber into the rear housing of the compressor, sparing it from damage.
With the engine off, grab the center hub of the compressor and spit it by hand clockwise. Describe how it feels when you turn it....
If this were my car, and I wanted long term reliable A/C I'd tear the whole system out of the car, flush the heat exchangers and piping to bare metal, replace the expansion valve, drier, compressor and all o-rings. There's no telling what has been done to it over the years, how much and what type of oil is in the system, etc etc.
Thread
Thread Starter
Forum
Replies
Last Post