Air con slow to cool on passenger side

[bennys8]

Originally Posted by BrianX54.4is

First check if the passenger side blows warmer with the A/C off and heater off (set to min temp but with A/C off). Could be that the heater valves on the passenger side are passing when they should be closed and re-heating the passenger side air when the A/C is on.

Also check that the cabin air temp sensors are not fouled with dust.

I believe it's the same temperature with the fan set to low and the AC off at about 70 degrees.

Should I shoot the air temp sensors with Dust Off (CO2 can for keyboard dust)?

[Rockmelon]

Originally Posted by haigha

Around the heater valve, the hoses all were around 150 F.

With the air on for about ten minutes, the vents read:

driver left: 50 F, middle left: 64 F, middle right: 78, far right: 79

have you tried refilling the freon? i understand that normal pressure range for inlet & outlet is around 1.5-2.2 bar and 12-22 bar. since driver side is cool and passenger side is warmer, the inlet pressure should be within normal range and outlet pressure should be on the low end. this suggests low freon and a possible leak somewhere. compressor should be fine since driver side is cooling. depending on how fast the same symptom recur after a refill, it just tells how bad the leak is. well i know of folks who would rather spend about $20-40 to refill freon every 2-3 months rather than change a leaking evaporator.

[Rockmelon]

Originally Posted by BrianX54.4is

If the passenger side blows warmer - then the heater valve or the control signals to the valve could be the problem. Attachment 42346

thanks, Brian. pls pardon my ignorance, i thought the X's aircon sys controls temp by regulating the blower fan speed when set to auto and according to whatever temp setting on the control panel? it does not really control the compressor which seems to be on all the time when cool ac is activated. the heater is only activated via a seperate push button on the control panel and switching to heater air duct is done manually via a rolling dial with blue and red color dots at the center air outlets? i noticed that heater air comes out only from the driver left & passenger right air outlets and not from the center air outlets.

[haigha]

Originally Posted by Rockmelon

have you tried refilling the freon? i understand that normal pressure range for inlet & outlet is around 1.5-2.2 bar and 12-22 bar. since driver side is cool and passenger side is warmer, the inlet pressure should be within normal range and outlet pressure should be on the low end. this suggests low freon and a possible leak somewhere. compressor should be fine since driver side is cooling. depending on how fast the same symptom recur after a refill, it just tells how bad the leak is. well i know of folks who would rather spend about $20-40 to refill freon every 2-3 months rather than change a leaking evaporator.

Thanks for the suggestion.

I did have it checked about a month ago so I discounted this as a problem area. However, my mechanic recommended we re-check this and we're going to this morning.

He told me on Wednesday that is what he first suspected and I thought the right side was blowing hot air until I checked it in the morning. It was blowing quite hot the first time I checked on Tuesday evening but it was 90 F outside

[Rockmelon]

i guess we are in the same boat. i did the refill this morning. inlet & outlet pressure went from 2.5/12 bar to 2.5/15bar. both sides are back to good cold air. my ambient temp here is now over 104. so now, i'm just waiting to see how long this will last before anything more drastic. cheers

[haigha]

Originally Posted by Rockmelon

i guess we are in the same boat. i did the refill this morning. inlet & outlet pressure went from 2.5/12 bar to 2.5/15bar. both sides are back to good cold air. my ambient temp here is now over 104. so now, i'm just waiting to see how long this will last before anything more drastic. cheers

Glad to hear it worked out for you I'll update the thread later today after we check mine out. I guess it's not unexpected that it could need a re-charge after 6.5 years

[haigha]

Update: I went to my mechanic and he added most of a can of R134a. He said that it's relatively common in our drier climate to need to add refrigerant every so often. He said that after 6.5 years adding this much is not a big deal but to keep an eye on it. He also said you have to be very careful not to add too much or it will make the problem worse.

When I used the infrared thermometer after it cooled down, the reading on the console vents was ~15 F

Total cost including refrigerant: $25
Having great folks at Xoutpost.com and a good mechanic: priceless

[BrianX54.4is]

Glad to hear that the refrigerant top-up has restored good cooling to both sides - but it also suggests a small gas leak somewhere on your system (albeit might be years before you need to top up again).

Just to answer your previous post....

Originally Posted by Rockmelon

...i thought the X's aircon sys controls temp by regulating the blower fan speed when set to auto and according to whatever temp setting on the control panel?....

Yes, but in addition it regulates the rate of flow of hot coolant into the heater coil - (driver and passenger side independently as they do not have independent blowers).

Originally Posted by Rockmelon

...it does not really control the compressor which seems to be on all the time when cool ac is activated...

Correct, the compressor is not regulated for cooling capacity. Compressor speed is however constant (stabilised) independent of engine speed.

Originally Posted by Rockmelon

...the heater is only activated via a seperate push button on the control panel...

No, this button just activates a pre-set program to direct warmed air at full fan speed to the windsheild and side windows only (for rapid de-frosting/de-misting). It also switches off cabin air re-circulation and cuts out the independent rear passengers upper vents fan.

Originally Posted by Rockmelon

...and switching to heater air duct is done manually via a rolling dial with blue and red color dots at the center air outlets?...

This dial allows for tweaking the temperature of the air coming from the centre and side driver & passenger upper vents independently of the footwell and windshield vents for increased comfort (warm feet and cooler air to the face reduce driver fatigue).

Originally Posted by Rockmelon

...i noticed that heater air comes out only from the driver left & passenger right air outlets and not from the center air outlets...

These vents are the side windows vents (above the drivers and front passenger side vents). Warm air is available to all vents when the de-misting program is not active (according to the temperature and centre vent dial settings).

Note also that air is drawn through both the cooling coil and then the heater coil. With A/C on the air is first cooled and de-humidified and then re-warmed if necessary according to the temperature settings. With the A/C switched on you can still have warm air everywhere or have cold air to one side and warm air to the other side at the same time.

Did everyone check that driver and passenger temperature settings were set the same when they noticed the passenger side not blowing cold???

[Steve972]

I had the same problem, however, mine was fixed by adding some more freon... you may want to see if your freon level is low..

[Rockmelon]

thanks Brian. i have learnt a lot today from your sharing. appre it.

i realized that it can sometimes be misleading when checking the air vent temp at the driver and passenger sides. when i first did this check, it was after the engine and ac had been running for some time with the min temp setting at 16 deg c at the passenger side and a higher temp setting at the driver side at 20 deg c. after switching off the ac, i found that the passenger side remained warmer.

then when i repeated the check before giving the ac any chance to work, i realized both air vents at driver and passenger sides gave the same temp when ac was off.

ha!