In mild temps the car was not cooling as well as it should; so, I went to the auto parts store and got a recharge can with built in gauge from a major mfg (AC (NOT) Pro). After 7+ years (car purchased summer 2006) this seemed reasonable.
So, when I started this saga I followed the advice of my local parts store and the instructions on a "recharge kit" that included a can of refrigerant mixed with oil, a gauge, and a hose.
Following the kit manufacturers directions led to initially better cooling but the gauge was showing lower low side pressure than they recommended. As I added more refrigerant the gauge did not change readings. At that point I assumed a faulty gauge and returned the combo to the store and got a new one from them. The second one did show different readings and did move higher as I added more to the system.
Cooling improved a bit more but still the system did not show the low side pressure recommended. As I added yet more refrigerant the system then stopped cooling all together.
At this point I assumed a second faulty gauge and that the system had been overcharged. With parts store assistance, removed some of the refrigerant from the system. Cooling resumed, but not as well as after just initially adding new refrigerant.
Several days later temps were high 90's low 100s (f). In city driving, the compressor seemed to shut off for long periods and the system would go from producing cold air to warm air. On highway driving the off periods were shorter and cold air more consistent. Assuming continued over pressure situation, more coolant was removed from the system.
Given the way the cans with built in hose/gauge work, besides likely overcharging the system I wonder whether some air was forced into the system. I also wonder about too much oil as the instructions recommended putting the can between upright and sideways while charging and I noticed that the fluid from the can was highly oily when some vented from an incorrect connection to the low side port.
I have now rented a manifold gauge and measured pressures. At 83 degrees F and low humidity (26%) the low side measured 30 and the high side 212 at idle. The high side was higher and low side a bit lower at 1500 rpm.
According to some of the high/low tables I've seen the low side seems to be too low and the high side is too high.
Based on everything I've read since starting this mess, I think I need to take it into a shop and have it fully evacuated and then refilled.
I do though read that it is better if the vacuum is left on the system for some time (e.g. overnight) in order to better dry the system out. Is that really true? Will most shops actually take that time or can I expect just a quick job and that part skipped?
Please advise me on the correct next steps for this situation. Is there anything that I should directly ask the shop to do or check at this point?
Is there likely an specific damage that all of this could have caused?
Finally, the other thing that would be helpful is to know whether it is ok the operate the AC at this point of would it be safer to service it first.
Other details:
Year: 2007 Mazda 3
Engine Size: 2.3
Refrigerant Type: r134a
Ambient Temp: 83
Pressure Low: 30
Pressure High: 212
Thanks!
So, when I started this saga I followed the advice of my local parts store and the instructions on a "recharge kit" that included a can of refrigerant mixed with oil, a gauge, and a hose.
Following the kit manufacturers directions led to initially better cooling but the gauge was showing lower low side pressure than they recommended. As I added more refrigerant the gauge did not change readings. At that point I assumed a faulty gauge and returned the combo to the store and got a new one from them. The second one did show different readings and did move higher as I added more to the system.
Cooling improved a bit more but still the system did not show the low side pressure recommended. As I added yet more refrigerant the system then stopped cooling all together.
At this point I assumed a second faulty gauge and that the system had been overcharged. With parts store assistance, removed some of the refrigerant from the system. Cooling resumed, but not as well as after just initially adding new refrigerant.
Several days later temps were high 90's low 100s (f). In city driving, the compressor seemed to shut off for long periods and the system would go from producing cold air to warm air. On highway driving the off periods were shorter and cold air more consistent. Assuming continued over pressure situation, more coolant was removed from the system.
Given the way the cans with built in hose/gauge work, besides likely overcharging the system I wonder whether some air was forced into the system. I also wonder about too much oil as the instructions recommended putting the can between upright and sideways while charging and I noticed that the fluid from the can was highly oily when some vented from an incorrect connection to the low side port.
I have now rented a manifold gauge and measured pressures. At 83 degrees F and low humidity (26%) the low side measured 30 and the high side 212 at idle. The high side was higher and low side a bit lower at 1500 rpm.
According to some of the high/low tables I've seen the low side seems to be too low and the high side is too high.
Based on everything I've read since starting this mess, I think I need to take it into a shop and have it fully evacuated and then refilled.
I do though read that it is better if the vacuum is left on the system for some time (e.g. overnight) in order to better dry the system out. Is that really true? Will most shops actually take that time or can I expect just a quick job and that part skipped?
Please advise me on the correct next steps for this situation. Is there anything that I should directly ask the shop to do or check at this point?
Is there likely an specific damage that all of this could have caused?
Finally, the other thing that would be helpful is to know whether it is ok the operate the AC at this point of would it be safer to service it first.
Other details:
Year: 2007 Mazda 3
Engine Size: 2.3
Refrigerant Type: r134a
Ambient Temp: 83
Pressure Low: 30
Pressure High: 212
Thanks!
