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Air temp can't make up its mind

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Old 08-13-2013, 01:43 PM
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Default Air temp can't make up its mind

Hi all,

When I get in my car in the morning over the last couple of weeks (very hot in my area) the ac blows very hot for about ten minutes then finally gets cold. Well yesterday it was cold in the am so I put the heat on and of course it blew as if I had the vent open, not actually ac cold, more like outside air temp but unlike the ac issue it never got hot even after an hour of driving. Again today same thing, any ideas what could be the issue?

James
 

Last edited by 4n6pi; 08-13-2013 at 01:51 PM.
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Old 08-14-2013, 08:12 AM
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Which year and engine?

On my 2005 T5 I had an issue with low coolant in the reservoir tank. The plastic was cracked and let coolant escape. Not sure why but low coolant level equals no interior heat.

Your A/C issue sounds like a low R134a charge. Does the compressor cycle constantly? A low charge will eventually cool the car but your compressor is working hard to keep up.

There is also a known issue with the compressor clutch on 2004.5 and up models. This issue, though, usually is described like this: the A/C cools normally for the first 30 minutes or so when it suddenly starts blowing warm air. After 10 minutes or so the A/C works normally again and the cycle repeats. The fix is the "deshimming" of the A/C clutch. This only takes a very short time to complete with hand tools.
 
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Old 08-27-2013, 08:41 AM
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Thanks for the reply,
2001 1.9 turbo

I will check the coolant, didnt think of that.

AC now seems to be fine, by itself I didnt fix or change anything so not sure what thats all about.

The mornings are colder now so I put the heat on and only cool air blows, although when I first posted the ac blew hot....


I will research and post back what I find.

thanks
 
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Old 08-28-2013, 10:02 AM
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With the A/C on high check for bubbles in the receiver/drier's window. It's located behind and below the drivers side headlight area. Small metal cylinder with a small round window on top. It may be dirty but is easily cleaned. Use a bright light to look for bubbles flowing past the window. A very low R134a charge will be indicated by lots of small bubbles like foam. The closer to full the bigger the bubbles.

When you refill the system you always charge with the can upright so that only gas flows into the system. Never turn the car upside down to let liquid enter the system. Why? Liquid cannot be compressed so dumping liquid into the low side will probably ruin the compressor. Charge until no more bubbles can be seen in the window.
 
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