did I overfill the AC system on my V6? cycling a lot now after recharge

[fenixus]

Hi,

Today I took my time to recharge the AC system on my 02 Solara V6 (1mz-fe), used only 1 can (12oz) to load it up. Reason was low pressure on running compressor (30-35psi).

now it seems like it jumped up to 45psi lowest, but after running the while pressure rises excessively and the compressor cycles off? not sure why it does that, is that normal after all?
I am not sure as before the pressure was always sitting in 30-35psi range (very low at 90F+ ambient) and it was not moving at all ever... like the compressor was running all the time maybe?

let me know what should I do with it, this a movie showing the low side pressure at full blast at idle on the gauge, it doesn't look right to me...

You Tube

You Tube

Thanks!

[Yuko]

At max A/C setting, the compressor shouldn't be cycling on and off. After watching your video, the system is still low on refrigeration. When it cycle the pressure drops too low and it stops to bring it up again. I would slowly add more R-134a until the compressor run continuously and the gauge reads steadily at the correct pressure.

Another problem (but not as likely) is that the compressor is not getting enought voltage and causing it to short cycles.

[capnblinski]

Hmmm.. That's odd. The reading shows full if not over when the compressor cycles on - but the cycles were so short that it's hard to tell.
And i'm sure it was warm enough in Jersey today to keep the comp cycled on for longer than that. When mine was charging, the comp stayed on (it was 95 degrees plus outside) and the reading stayed in the low zone and then gradually worked its way up to approx. the 50 PSI range and has stayed there since. Of course the PSI reading will read lower when the ambient temperatures are lower.

The reason for the rapid on-off cycling seems to lie somewhere else. I'll check again and let you know where my PSI goes to when the comp cycles off - now that it's gotten cool enough here in sw pa. for that to happen! The temps are supposed to drop to near 50 tonight here.


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[JohnGD]

I think about 1/4 to 1/3 can after 4-5 years is all it takes if things are "normal". If you filled up with the whole can then it's too much.

The Walmart can is great for typical maintenance because my trusty AC guy charges $60 for a "top off" and $120 for a proper vacuum and charge. And my wallet knows first hand that most AC shops out there don't have a clue about what they're doing, including a dealership and a chain store.

Was it low on freon? Bubbles in the sight glass?

[pmesfun]

Yeah, a whole can seems like too much, I remember I used a can and a half when the system was basically empty.

[fenixus]

ok, guys thanks for replies, I see your points, but I think here is another problem and is not quite pressure related (or is it) as system was loaded max to 45psi while even 55psi would be OK. it's something else causing the compressor to disengage. I have a noise now too, realized that only after I started driving the car, it can be heard from cabin only.

This AC system was working fine (ice cold), but showing me only very little pressure on Low Side when compressor was running (Magnetic Clutch engaged and spinning), my gauge was showing usually 30-35psi even when there was like 105F out there. kinda weird. should be like 55psi at such ambient temperature.

I figured, it needs more gas, maybe it will be cooling even better. wrong.
I added 1 can and the pressure has risen to 45psi (at around 90F) which is good .. but during the end of charging process the compressor started cycling like crazy (Magnetic Clutch was clicking every few seconds). The end result, it's not blowing cold air at all, as the M/C disengages it after 2-3 seconds, then tries again and again it turns off. I have luke warm air coming out of vents now.

I went ahead and evacuated some freon from system, thinking it must be it (pressure too high, pressure switch tells it to shut off) and it helped a little, but problem is still there (pressure switch faulty?) just less frequent, so at least now I have cold air blowing, but the compressor is not running right at full blast (M/C engages and disengages every few seconds still)... and now there is low vibrating noise sometimes when compressor is engaged (then it shuts off).
the noise started showing itself also when system was loaded up to 45psi (it's still low!!!).

basically in above (1st post) movie, when the gauge shows 45psi is when the compressor is running (M/C engaged, pulley spinning), then when you hear relay click is when M/C disengages the compressor, so the pressure rises on Low side (normal when compressor doesn't run). question is why it does not want to run continuously?

on top of that all I can now hear some nasty vibrating sounds/noises in cabin (only!) when the a/c is running... it almost sounds like submarine walls taking too much pressure under water or so ... recorded 2 more movies from the cabin, observe the RPM gauge, you will see when the A/C compressor disengages (temporary spike in RPM as IAC compensates). I hope you can hear the noise, it's scary and it happens only when a/c compressor actually runs... once the noise appears it takes only a few seconds and M/C disengages the compressor, then it tries engaging it again and story repeats. noise doesn't happen always though!

have both system and youtube volume turned up to max and use headphones, you will hear a strange low vibrating noise on many occasions in below movies..

You Tube

You Tube

You Tube

You Tube

EDIT:
I can evacuate more freon tomorrow, but it will mean the system will have again only 30psi of gas on the Low side (when running)? right now it shows between 35-40psi when a/c runs. still way below specs .. any reason why it cannot work with normal pressure of gas? some part failing in system?

[JohnGD]

Yes, you had normal working pressure. Over charging can stress out the compressor too. I'm not sure if you should look at one of those $120 service now.

[fenixus]

yeah, I'm sure I have NOT over-charged it at all. It could probably take 1 more can (small 12oz) and the pressure would be at higher edge of max limit for a normal 134a system, Low Side is all right up to 55psi at 95F+.

problem is the strange noise that I can hear from cabin only and which is related to compressor turning off (M/C clicks and turns it off) shortly after the noise starts.

A/C light is not blinking, it's normal solid. I even have cold air blowing now, just that noise ... it was a bad day for working on car ... whatever I touched, everything is f**ked...

I can evacuate more gas tomorrow and see if it starts working again normally at 30-35psi. if noise is still there, then some part is faulty (but what is it?) and I doubt it all starts working right after simple vacuum and refill ... though it would be interesting to see if system holds vacuum properly ... just that $120 is a pain, I think it's $150 nowadays (vacuum and full recharge) in NJ ...

also the bigger problem could be that let's say the system holds vacuum correctly and they fill it with gas (up to 55psi) and then my problem starts again, compressor switches on and off, resulting in no cold air and my wallet is lighter by $150 ...

Originally Posted by JohnGD

Yes, you had normal working pressure. Over charging can stress out the compressor too. I'm not sure if you should look at one of those $120 service now.

[JohnGD]

55 is probably only for Detroit accumulator systems. I remember Ford's garter spring connection for the AC and fuel systems. Those sucked big time. Not sure if they changed it, I should have checked when I drove one of their new trucks the other day - nice and smooth. The 6-speed isn't as good as GM's Hydramatic 6L/6T series IMO, even if they're jointly developed for some reason. And the ergonomics and layout still don't cut it. I think Apple got all the top design talent.

Anyways, import's better expansion design will keep it around 30 or so automatically so you can't charge that way. At the first sign of bubbles in the sight glass (while running, not when cycling off) just add 1/4 to 1/3 can. This should give you a trouble free system for years.

[fenixus]

John, I think you are missing the point.

I have added 17oz of gas to wife's 5s-fe car a day before and pressure shows now 45-55psi on Low Side and everything works right.

On my 1mz-fe car it does not work right anywhere past 35psi for some reason ... also I have the strange noise which means something (a clog in system? a stuck valve somewhere?). can only see if system starts working normally after bringing the pressure down to 30psi, but again even if it does then it's only a workaround, not a fix to the real problem.

will be reading Air Conditioning manual for V6 which I downloaded recently from TIS and see about some tests and troubleshooting over there. something is not right, it should not be like that.

Originally Posted by JohnGD

55 is probably only for Detroit accumulator systems. I remember Ford's garter spring connection for the AC and fuel systems. Those sucked big time. Not sure if they changed it, I should have checked when I drove one of their new trucks the other day - nice and smooth. The 6-speed isn't as good as GM's Hydramatic 6L/6T series IMO. And the ergonomics and layout still don't cut it. I think Apple got all the top design talent.

Anyways, the import's better expansion design will keep it around 30 or so automatically so you can't charge that way. At the first sign of bubbles in the sight glass (while running, not when cycling off) just add 1/4 to 1/3 can.

[dave1811]

What is your high side pressure reading? At 95 degrees out, I believe it should be around 200-250 or so. If your low side pressure is okay but your high side pressure is too high, your expansion valve might be sticking open. The symptoms of that are blowing warm air and possibly moisture or frost on the evaporator and/or low side refrigerant line according to the Haynes AC manual I have.

My mom complained about her AC not working on her 2000 Corolla after my brother had "filled" it up. When I asked my brother, he said he just put a can of refrigerant in it, didn't check the pressures. I put a set of gauges on it and found he had overcharged the system. It blew warm air and the compressor wasn't cycling. I got the loaner vacuum pump from Autozone, vacuumed it, refilled it to the right pressures, and now it works fine. That was 3 months ago in hot west Texas.

Just saying, it helps to check both sides of the system, low side and high side pressures.....

[Bdub215]

Originally Posted by fenixus

John, I think you are missing the point.

I have added 17oz of gas to wife's 5s-fe car a day before and pressure shows now 45-55psi on Low Side and everything works right.

On my 1mz-fe car it does not work right anywhere past 35psi for some reason ... also I have the strange noise which means something (a clog in system? a stuck valve somewhere?). can only see if system starts working normally after bringing the pressure down to 30psi, but again even if it does then it's only a workaround, not a fix to the real problem.

will be reading Air Conditioning manual for V6 which I downloaded recently from TIS and see about some tests and troubleshooting over there. something is not right, it should not be like that.

all i can suggest is make sure your condenser is clear of debris cause that could freeze up the system pretty quickly. what kind of gauges are you using that your getting these pressure readings with?

[fenixus]

I don't know how to check the high side pressure. My gauge fits only the Low side.

I'd like to know what both sides are saying, could be interesting to see.

is it possible that Low Side is showing very low pressure (30psi) while high side could be way past the spec limits?

also, which side of system the pressure switch resides on and reads? high side?

perhaps it's cycling the compressor off, because the high side is too high while low side stays too low? just guessing.

need to vent more gas tomorrow.

Originally Posted by dave1811

What is your high side pressure reading? At 95 degrees out, I believe it should be around 200-250 or so. If your low side pressure is okay but your high side pressure is too high, your expansion valve might be sticking open. The symptoms of that are blowing warm air and possibly moisture or frost on the evaporator and/or low side refrigerant line according to the Haynes AC manual I have.

My mom complained about her AC not working on her 2000 Corolla after my brother had "filled" it up. When I asked my brother, he said he just put a can of refrigerant in it, didn't check the pressures. I put a set of gauges on it and found he had overcharged the system. It blew warm air and the compressor wasn't cycling. I got the loaner vacuum pump from Autozone, vacuumed it, refilled it to the right pressures, and now it works fine. That was 3 months ago in hot west Texas.

Just saying, it helps to check both sides of the system, low side and high side pressures.....

I am using a gauge that left after using the 17oz Interdynamics refrigerant can (thin long one).
It's actually a "re-usable trigger dispenser with a gauge", but it's useless as a dispenser - the trigger arm locks against wider body of small 12oz cans and can't dispense anything, learned it the hard way and wasted 1 can of good synthetic refrigerant, had to vent it all to air to remove the "re-usable" dispenser from it ... it works fine as a Low Side gauge though and can be used to vent the gas too if needed.

Originally Posted by Bdub215

all i can suggest is make sure your condenser is clear of debris cause that could freeze up the system pretty quickly. what kind of gauges are you using that your getting these pressure readings with?

[JohnGD]

Actually the 5SFE is over charged too.

Originally Posted by fenixus

I have added 17oz of gas to wife's 5s-fe car a day before and pressure shows now 45-55psi on Low Side and everything works right.

[fenixus]

really

I guess will need to vent it a little bit too ... need to find specs for low side pressure on 5s-fe and 1mz-fe ...

so far I only found that refrigerant charge volume (full refill) is up to 30oz.

Originally Posted by JohnGD

Actually the 5SFE is over charged too.