How often does your AC compressor cycles?

[AtomicPunk]

Hi AtomicPunk, the detector did not go off when the cap is on and tight, it only triggers the alarm without the cap and the tip of sensor very close to it. Could that probably caused by my repeatedly connecting to the gauge and damaged the valve?

Well, this will kick off a debate, but the Schroeder valve is an access point (or hole) in an otherwise closed (and pressurized) system. Just a little o-ring and proper seating keep it sealed. But in my experience, the detector is so sensitive that it picks up miniscule leaks around the valves, but with the cap on it won't. The cap is to keep dirt out of the Schrader valve, but I also think the cap helps seal, too.

I wouldn't get overly concerned with the detector going off at the valve with the cap off and not when cap is on. I doubt you damaged the valve by accessing it. It's POSSIBLE it might need a new valve, but I don't think what you are experiencing is that uncommon. I'd be more concerned if the detector is going off elsewhere.

[luckyforrest]

Well, this will kick off a debate, but the Schroeder valve is an access point (or hole) in an otherwise closed (and pressurized) system. Just a little o-ring and proper seating keep it sealed. But in my experience, the detector is so sensitive that it picks up miniscule leaks around the valves, but with the cap on it won't. The cap is to keep dirt out of the Schrader valve, but I also think the cap helps seal, too.

I wouldn't get overly concerned with the detector going off at the valve with the cap off and not when cap is on. I doubt you damaged the valve by accessing it. It's POSSIBLE it might need a new valve, but I don't think what you are experiencing is that uncommon. I'd be more concerned if the detector is going off elsewhere.

Thank you! I also used the sniffer to check another old car that is low on refrigerant, the sniffer also went off with the low side cap off. Guess it is a common issue. One thing I noticed yesterday was when I removed the Low side cap, I can feel there was some weak pressure from that valve, which is very likely caused by the r134a built up inside the cap. I found this video below, at 14:00, Eric suggested to reset the valve after the service. I will try this after I check both L and H pressure of the AC later today.

[luckyforrest]

Hi all, I finally got the manifold gauge and measured Low and High pressure while idling. The L pressure fluctuate at 26-45 PSI (26 psi while compressor engaged, 45 psi when paused), the H pressure stabled at 170 psi, ambient temp. was about 26-27 Celsius, humidity 51%. I compared the above pressures against the standard pressure chart on the user manual of manifold gauge, they look normal, or very close to normal. This makes me very confused: I recharged about 80-90 grams of r134a about 2 weeks ago, and yesterday I recharged another 70 grams, so total amount injected into the system was about 160 grams, thinking the capacity of AC in Mirage is only 270 grams, I realized I might have a severe overcharge, so I measured the pressure of both L and H today. The thing is the pressure is still normal after injecting that much refrigerant that makes me confused. My AC works well before my second recharge (5-6 degrees Celsius at cruising speed), and after the second recharge yesterday, the air vent temp. barely went down, maybe 0.5-1 degrees lower only. So, I guess the AC indeed has a leak and had low level of refrigerant for a while already. Any new Mirage owners checked the L and H pressure after purchase? Very curious to know if the AC was fully charged by manufacture.

[7milesout]

LF - So, kind of scrap some of the things I said before ... at least about cycling. I got in my car last night about 7 pm. After heating soaking the car from lots of hard work, but not running the A.C. I turned on the A.C. for my maneuvers around in the driveway and sure enough, it cycled. I'm about 90% sure that's what it was doing. I can't say for sure why. The A.C. system wasn't used during my 225 mile towing event, but even though it was not, I would think the system would be warmed up from all the residual heat under the hood. However, I could be wrong. Perhaps the compressor was still quite cool, and firing it up at that time, the whole system wasn't fully warmed up. Just a big crap shoot and I'm only speculating.

As for the charge in your system, I don't think you should concern yourself about overcharging (with where your system is now). The high pressure side will shut the system off if it sees too much pressure. As for the pressures you're seeing and the confusion ... that's why trying to judge your system via pressure is not the best way. The low numbers you are seeing on the low side are really the only numbers you should consider important.

I would have to say that if the low side pressure switch shuts things down at say (this is a guess) 26 psi, having it run at 28 to 30 psi is optimal. You want it to be fairly close to the low side shut off. It being in a low pressure zone while operating DOES NOT NECCESARILY mean it is low on capacity. You're doing everything right, as far as I can see.

My system also increases temp somewhat at idle. So I wouldn't be so concerned about that either. That valve reset sounds interesting. I'll want to learn more about that.

[7milesout]

Pulling this up right at a year later. My car is now cycling more rapidly than it was last year. To me, it certainly gives me the impression that it has leaked refrigerant.

But I'm at a crossroads. A dealer is not exactly close. And taking it there for an A/C check / service will likely turn into an all day hassle. I'm at 33k miles, so I think they'd check and service it (if they find it requiring it) and not charge me.

The difficulty in deciding to do that is, I think they'll do crap level work, probably break some stuff, and then tell me I need whole new this, that and the other. And try to sell me blinker fluid. And basically, waste a whole day.

Or I could just evacuate it and recharge it myself. What to do ...

I'm thinking I'll do it myself. Best case scenario is that they find that it has a refrigerant leak, and they repair it. However, in my process of recharging, I can tell if it has a leak or not. If it does, I can take it too them under the same circumstances as right now, and get it repaired for free.

What's the consensus here team?

[defensivetackle99]

Pulling this up right at a year later. My car is now cycling more rapidly than it was last year. To me, it certainly gives me the impression that it has leaked refrigerant.

But I'm at a crossroads. A dealer is not exactly close. And taking it there for an A/C check / service will likely turn into an all day hassle. I'm at 33k miles, so I think they'd check and service it (if they find it requiring it) and not charge me.

The difficulty in deciding to do that is, I think they'll do crap level work, probably break some stuff, and then tell me I need whole new this, that and the other. And try to sell me blinker fluid. And basically, waste a whole day.

Or I could just evacuate it and recharge it myself. What to do ...

I'm thinking I'll do it myself. Best case scenario is that they find that it has a refrigerant leak, and they repair it. However, in my process of recharging, I can tell if it has a leak or not. If it does, I can take it too them under the same circumstances as right now, and get it repaired for free.

What's the consensus here team?

Would you be covered for warranty claim? I really don’t know.

[7milesout]

Good question.

If they knew I had serviced it myself, they could reject warranty. I don't know how they would ever know.

[defensivetackle99]

Good question.

If they knew I had serviced it myself, they could reject warranty. I don't know how they would ever know.

I see. What if you take it to the reputable A/C shop and ask for their opinion? I thought it safer and cost effective than the dealership? I cannot imagine the dealership would deny future warranty claim just for taking the 3rd party shop. Just my thought.

[7milesout]

I'm my own 3rd party shop outside the dealership ... where I can. I don't know of any other 3rd party shops that wouldn't give me the ole, "oh this thing is blown, you need a whole new A/C system." They're all out to generate revenue. Honest places are nearly impossible to find.

[Fummins]

Figured you'd like to hear this....I have a 2021 Nissan in the shop with a seized ac compressor. Good job Nissan....out of the 4-5 2021' Nissans we have, every single one has had an ac problem this spring. Either just needed a top off(Ac charge warranty is 1 year!), or had o-rings leak(very visable), or this one with a effered ac compressor at 114k kms. Thankfully basic warranty is 160k km/5year so hopefully they eat this job. Oh and they use the pricey y1234 refrigerant that cost about $300 to recharge last time.