Is it possible that the A/C compressor cycles even if the system has the full amount of refrigerant? That is what it is doing in my car. But dont believe its low because air out of the vents still blows cold. I also evacuated, checked for leaks, and refilled the system with the machine about 3 months ago when I bought the car. The machine removed a little less than the maximum amount the system holds. I figured this was normal for a 10 year old car. The temperature of the air out of the vents goes back and forth from 42 to about 48 or so. I assume this isnt normal either. I was told my compressor could be on its way out because of the cycling and if the system has not leaked out any refrigerant. Is this true? Are the compressors on these cars known for problems? I'm going to do some more testing this week and put it on the machine again and see how much refrigerant is in the system.
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2006 Corolla S - sold
2003 Solara SLE - sold
2000 Corolla LE - sold
If anyone who uses the A/C can notice if the compressor cycles on and off after driving a while, I'd appreciate it. I learned that its normal for some cars to have it cycle, as opposed to have it run continuously like on other cars I own. So I just want to know if its normal for the 8th gen. Corolla.
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2006 Corolla S - sold
2003 Solara SLE - sold
2000 Corolla LE - sold
So I stopped worrying about this issue and just assumed that it was normal, as I noticed that other Toyota/Lexus cars at work also cycled the compressor. However, now that the temperatures are getting hotter, recently I've noticed that the compressor on my car cycles even more frequently sometimes. Enough so that while I'm accelerating, it makes the car feel like it has a hesitation or that the transmission is going bad. This is VERY annoying and dont believe its normal. Its definitely being caused by the compressor cycling because when I turn off the A/C, the car moves smoothly. I also opened the hood one time and could see the compressor cycling even quicker. Also it seems to do it more when the car is first started and the interior is hot. I dont see this being normal and hopefully I can get a straight answer . A/C still blows cold, although when its cycling fast, I can feel the air get less cool.
Has anyone noticed this at all in their cars? Like I said, I believe the compressor cycles on these cars (unlike other cars I've owned where it stays on permanently). However, I dont believe its supposed to cycle fast enough that it makes it feel like there is something wrong with the engine or drivetrain of the car.
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2006 Corolla S - sold
2003 Solara SLE - sold
2000 Corolla LE - sold
Yes, it is normal for your compressor to cycle on and off. It will stay on longer or maybe even continously it it is hot and very humid, but other wise cycling is normal. 42-48F duct temp (recirc off) with the blower fan on high is also normal. I too can feel the compressor cut in while driving - its using at least 5% of your horsepower to operate, so you will notice the load. This will be minimized by a well tuned engine. Try new sparkplugs if the're not recent. Make sure the cooling fan will cycle from the A/C while parked, be sure the condensor fins are clear, not plugged with dirt, bugs, or folded over fins. Also be sure the system isn't overcharged - a small capacity system is very sensitve to ovecharing and could cause it to cycle too rapidly if it is overpressuring. Good air flow from the ducts is essential as well, an evaporator core that's plugged externally or heater box full of leaves, etc will also cause it to cycle faster than normal. Good luck.
PS. When you say it "cycles fast", how many seconds roughly, for a complete on/off cycle of the compresor?
Yes, it is normal for your compressor to cycle on and off. It will stay on longer or maybe even continously it it is hot and very humid, but other wise cycling is normal. 42-48F duct temp (recirc off) with the blower fan on high is also normal. I too can feel the compressor cut in while driving - its using at least 5% of your horsepower to operate, so you will notice the load. This will be minimized by a well tuned engine. Try new sparkplugs if the're not recent. Make sure the cooling fan will cycle from the A/C while parked, be sure the condensor fins are clear, not plugged with dirt, bugs, or folded over fins. Also be sure the system isn't overcharged - a small capacity system is very sensitve to ovecharing and could cause it to cycle too rapidly if it is overpressuring. Good air flow from the ducts is essential as well, an evaporator core that's plugged externally or heater box full of leaves, etc will also cause it to cycle faster than normal. Good luck.
PS. When you say it "cycles fast", how many seconds roughly, for a complete on/off cycle of the compresor?
Hopefully its something that I'm able to figure out. I understand its normal to feel the engagement and disengagement while driving, but since it does it faster than normal, it feels like there's something wrong with the actual car and its extremely annoying.
Would the maximum amount of refrigerant (according to the sticker under the hood) make it behave as if it were overfilled? As opposed to a slightly lower amount?
When it cycles normally, compressor is on for about 30 seconds or so, then off for about 10. When its fast, compressor is on about literally 3 seconds, then off again for another 3, etc. And this is what I feel when driving. Doesnt seem normal.
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2006 Corolla S - sold
2003 Solara SLE - sold
2000 Corolla LE - sold
Yes, 3 second cycles are an issue. You could try lowering the charge to minimum spec or halfway in between. It can be very difficult to recover every last bit of refrigerant from the system, especially in colder ambient temperatures, and since you say you recovered less than spec, I'm thinking a small amount was left in the system, and creating an overcharge by re-charging to max spec. It's easy to recover the difference between max and min spec, so I'd start there.
If you can duplicate the issue parked, connect the gauges or machine and watch the pressures as it does this rapid cycling. The low side should not be dropping below 10 psi min, and the high side should not be immediatly climbing over 200 psi. It should gradually reach 325-350 psi before the engine fan comes on, but it should take a bit. If the high side pressure immediatly hits 300+psi when the compressor cuts in and/or the low side drops to zero or negative pressure, it's probably a plugged/stuck expansion valve. Also check the a/c clutch relay and power to the compressor clutch to make sure it's not simply a poor electrical connection. Hope this helps.
Yes, 3 second cycles are an issue. You could try lowering the charge to minimum spec or halfway in between. It can be very difficult to recover every last bit of refrigerant from the system, especially in colder ambient temperatures, and since you say you recovered less than spec, I'm thinking a small amount was left in the system, and creating an overcharge by re-charging to max spec. It's easy to recover the difference between max and min spec, so I'd start there.
If you can duplicate the issue parked, connect the gauges or machine and watch the pressures as it does this rapid cycling. The low side should not be dropping below 10 psi min, and the high side should not be immediatly climbing over 200 psi. It should gradually reach 325-350 psi before the engine fan comes on, but it should take a bit. If the high side pressure immediatly hits 300+psi when the compressor cuts in and/or the low side drops to zero or negative pressure, it's probably a plugged/stuck expansion valve. Also check the a/c clutch relay and power to the compressor clutch to make sure it's not simply a poor electrical connection. Hope this helps.
Great, thanks. Will try it out and see what I find.
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2006 Corolla S - sold
2003 Solara SLE - sold
2000 Corolla LE - sold
So I hooked up the A/C machine and recovered 1.34 lbs. Dont know if this would indicate a slight leak, as months prior to this, I charged with the maximum amount which is 1.54. But after recovering, I charged with 1.32 which is the minimum. Since then I have not had the issue of the compressor cycling frequently. It now cycles at the normal rate and I no longer feel that "jerking" that I was feeling while driving as the compressor cycled on and off repeatedly, and the air out of the vents is nice and cold.
__________________
2006 Corolla S - sold
2003 Solara SLE - sold
2000 Corolla LE - sold
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