Automotive AC help requested

[Number_35]

Hello all - I have an AC question on behalf of a friend who drives an older ('06 or '07) Mazda 5 (2.3 l Duratec w/ 4-speed automatic). The AC will blow cold for a couple of minutes, and then will blow ambient-temperature air after that. (I checked this myself; it was quite a hot day, and the air coming out of the vents was definitely much colder than ambient for a couple of minutes.)

I don't see how this would possibly make a difference as the air flow is good, but the cabin air filter has not been changed in several years, and possibly not ever.

For what it's worth, the AC in my '09 Mazda 5 (mechanically very similar to my friend's) still works very well. When I changed the cabin air filter last summer, it was quite disgusting but AC efficiency had not been compromised.

I'm guessing that in my friend's case, the AC has a slow leak and needs to be recharged.

Thanks in advance!

 

[Chris142]

Is the compressor running when it warms up? If its cold the ac is sufficiently charged. My guess is an ac clutch relay is getting hot and opening up. Turning off the compressor.

 

[windeye]

OP, per post above, u can observe the AC compressor clutch engagement, to see if it is engaged for a few min and then disengage.

 

[LazyDog]

Does it have an automatic mode for the AC, change it to manual mode see if it does the same thing!

 

[Audios]

Expansion valve is clogging would be my guess, or compressor clutch is slipping under heavier loads.

 

[Chris142]

Originally Posted by Audios
Expansion valve is clogging would be my guess, or compressor clutch is slipping under heavier loads.

If that's the case he has huge problems!

 

[RayCJ]

My wife's 07 Mazda6 did the same thing several years ago. There was not enough refrigerant in the system to maintain consistent pressure. It would run for a while then cut out. It needed a re-charge and it was not a big deal. Since your system is still able to blow a little cold air, the system is still pressurized and has not been contaminated with outside atmosphere. Take it to a reputable place and have them recharge the system.

Unless they can prove there's something else wrong, don't let them give you a line of BS and charge you for complete evacuation and refill.

Ray

 

[Oro_O]

Alternatively, has it been serviced recently (likely not or you would have said). Ask them - because a slight overcharge can also create this situation.

 

[mehullica]

Without pressure readings, you're just wasting time. Have a shop hookup gauges & see what's happening