A/C compressor pressures?

GMANSCHULT

MEMBER
2011 TOYOTA COROLLA
1.8L
4 CYL
2WD
AUTOMATIC
115,000 MILES

No movement on gauges until 2 minutes after I start the car. Pressures stabilize at 150 high 50 low. A/C is cold until about 90 degrees then starts to blow only cool air, not cold. A/C condenser fan is working in high mode. I have the condenser fan jumped to 12 volts as it wasn't kicking on high for a reason I don't know. Maybe the compressor is going bad, maybe solenoid valve. Hopefully you can help shed some light on it.

7 Replies

JACOBANDNICKOLAS

MECHANIC
108,164 POSTS

Hi,

It sounds like either the compressor is failing, or the compressor clutch isn't fully engaging.

I question the pressures. If the ambient temperature was 90 degrees F, the low-pressure reading you have is perfect, but the high pressure is very low. I would expect it to be around 250 PSI to 270 PSI.

When the system starts to build pressure, are there any odd sounds you are noticing? Also, take a look through this link and let me know if anything helps:

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Let me know.

Take care,

Joe

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Wednesday, August 3rd, 2022 AT 8:13 PM

GMANSCHULT

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4 POSTS

Hi Joe, thanks for the reply. The compressor is quiet as a mouse, no strange noises. The temperature was 87 when I got those pressures. I believe my compressor is variable displacement. On cloudy days it works great, but when the sun comes out or in the heat of the day it barely keeps the car cool. Thanks again.

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Wednesday, August 3rd, 2022 AT 8:43 PM

JACOBANDNICKOLAS

MECHANIC
108,164 POSTS

Hi,

If it is variable, I would still think the high pressure would have been higher, especially if it wasn't cooling and the temperature was near 90.

Do me a favor. Let me know if the system has automatic climate control or manual control. I want to read through the diagnostic info, but it goes two different ways based on the system. See pic below

Let me know.

Joe

See pic below.

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Thursday, August 4th, 2022 AT 4:24 PM

GMANSCHULT

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4 POSTS

Hi Joe. It is manual.

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Thursday, August 4th, 2022 AT 7:29 PM

JACOBANDNICKOLAS

MECHANIC
108,164 POSTS

Hi,

Thanks. I went into the manual diagnostics and found nothing. See pic 1.

Since it takes a couple of minutes until the pressure builds, my first suspects are low refrigerant, or the compressor is failing. The compressor itself would be more likely with the pressures.

Have you tried vacuuming the system down and then recharging it?

Let me know.

Joe

See pic below and sorry for the manual's lack of help.

Image (Click to make bigger)