ac

[m4rkw]

If it blows ice cold one side but not the other then the refrigerant level is fine, as @Herbie says it'll likely be one of the doors malfunctioning and not directing the cool air where it's supposed to go. Assuming of course you haven't got the manual vent door control halfway shut xD

I think there is a relearn procedure for those on many cars, they have to learn where the home position is after a Battery disconnect. Not sure if it just happens by itself or whether you can trigger it somehow but might be worth a shot?

@Herbie are you sure its normal for the AC to be warmer at idle? I always thought that was indicative of a weak or failed fan, but I guess if it's a very hot day then the system only has so much cooling capacity even with the fans on.

[Spacewagon52]

I would have a regas and leak check and then go from there (cost around £70)

 

[m4rkw]

2 minutes ago, Spacewagon52 said:

I would have a regas and leak check and then go from there (cost around £70)

 

No disrespect intended David but that would be a waste of money if the system is blowing cold enough through one side of the vents. This fact proves it is not a refrigerant issue because there's only one heat exchange process taking place and if there's cold air blowing anywhere then that part of the system is working. If it was low on refrigerant or leaking it would be blowing warm everywhere. Assuming of course that the cold air is as cold as it should be, but it sounds like that is the case here.

[ColinBarber]

2 hours ago, m4rkw said:

are you sure its normal for the AC to be warmer at idle? I always thought that was indicative of a weak or failed fan, but I guess if it's a very hot day then the system only has so much cooling capacity even with the fans on.

If the compressor is driven mechanically via the engine (as in the case of the RX300) then it may not be spinning fast enough at idle to give maximum cooling, in a similar way to the alternator not putting out full power at idle, so not just the cooling effect from air movement.

[m4rkw]

5 minutes ago, ColinBarber said:

If the compressor is driven mechanically via the engine (as in the case of the RX300) then it may not be spinning fast enough at idle to give maximum cooling, in a similar way to the alternator not putting out full power at idle, so not just the cooling effect from air movement.

Ah i see, makes sense 

[PCM]

I have to say... my RX300 Air Con is brilliant! Summer and Winter.

Back in the day, when cold, it made a clicking sound. I believe it was a plastic cog, on the way out. The sound drove me mad!(er).

Fixed under my then, Lexus Warranty.

Which is why... despite the distance, I would be getting the dealer to resolve it ( and any other issues. )

[m4rkw]

To explain the vent door issue a bit more - the AC system doesn’t actually cool, it removes heat which has the effect of cooling. This is done centrally and then the cold air is re-heated through the vent system according to the temperature setting of the climate control. The same cold air from the heat exchange goes to all vents, so if one is cold and another is warm then the AC heat exchange is working (ie not a refrigerant issue) but one of the vent doors is in the wrong position causing warm air to re-heat cold air on one side (assuming of course this isn’t set as different via dual-zone etc).

[m4rkw]

Also, regardless of what you think an issue might be, it's never a good idea to go to a garage and ask for a specific thing to be done unless you are absolutely 100% sure of the diagnosis. Garages will often do exactly as you ask and give you the car back with the same problem, and in all fairness it's likely a problem you never even told them about. A great garage will start by asking you what problem you're trying to fix by doing this and then advise you that regassing the aircon isn't going to fix it, but there are plenty who will just take the money.

If you go to them and just describe the problem you're having then if whatever they do to fix it doesn't work then it's their problem not yours.

I agree with @PCM that this should be resolved with the dealer, depending on where the vent is and how it's accessed it could potentially be a big job if lots of the dash has to come out to get to it.