Air con and revs

SeanR · August 12, 2022

Was only joking how car the reliable is but anyways noticed something unusual today.

If air con broke, not bothered, will live without it. Went like this.............

Gets in car, its boiling hot.

Winds windows down

Turns climate auto on and puts temp to minimum and on full blast, thought il put windows back up when cold air comes out.

Starts driving, gets to lights and revs start going up and down, thought thats weird, remembered a thread a bit earlier with regards cutting out, mine didnt cut out.

I turns off Auto (climate) and engine revs return to normal

I puts windows up and carry on driving.

I turns Auto temp back on again and turns temp up, it does it again so i turns off again.

I starts driving again but this time turn off full blast and puts it on medium, temp down to minimum

Everything now working ok

Only used aircon twice, didnt have an issue the first time.

Was only serviced at Lexus last July, interim.

Is it something ive done ?, or maybe an issue.?

Cheers.

Linas.P · August 12, 2022

Faulty A/C compressor and or A/C clutch.

Had exactly the same problem. Some say A/C does not need servicing, but Lexus recommends doing it every 2 years. Again some say just keep it ON (which I agree with - it should never under any circumstances be OFF) and don't bother with service, but I rather pay £60 for re-gas and oiling every two years than pay £700 for new compressor and fitting.

I note you said you only used it twice - that is part of the problem, A/C should never be off, that causes seals to dry out (as oil circulates with refrigerant), then oil/refrigerant leaks trough dried out seals and once lubrication is lost or insufficient A/C compressor seizes. Not only that - having A/C off for longer periods of time just promoted bacteria growth and when you turn it on it not only stinks like swamp, but may be dangerous for your health.

In your case maybe it seized momentary on dry start, but luckily got some lubrication and started working again... that is not to say it wasn't damaged.

SeanR · August 12, 2022

Thanks Linas,

I will see how it goes.

Over the next few weeks i will leave it on and just use the temp

Will this not use a lot more petrol though ?

SeanR · August 12, 2022

Just had a look over your thread Linas, some good info.

As long as i get hot air in winter, thats the worry.

Its hot at the moment here but lets face it, its not tenerife.

I can live without cold air,

Stripped aircon out of 2 cars in the past, so not a killer for me

Las Palmas · August 12, 2022

The bigger the engine the less part of fuel consumption will be to the air-condition.

Yes nothing works without energy and the energy for getting cold dry air comes from the engine that will need more fuel.

But as just mentioned: dry air. Help keep your car dry in winter.

Never turn off air-condition in our car.

SeanR · August 12, 2022

Ps, booked in for a service and back brakes next week at a local garage, will ask about regas and oil, cheers

Linas.P · August 12, 2022

Sadly it is not an option to turn it off if you car has it, if it is fitted it must be on... unless you into hobby of growing fungus on condenser.

A lot more fuel? Depends on the driving but no more than 1-2% would be the norm, certainly cheaper than repair bill. One thing to note - I always have car in recirculation more (I can't even understand how people can drive otherwise), when I start driving I may slightly open a window/sunroof or have it fresh air mode, but as soon as I reach main road, recirculation is turned on and it just keeps pleasant temperature with minimal fuel consumption impact.

It does not matter what is temperature outside either, A/C works all the way to 0C and it not only cools, but as well... conditions the air, meaning it removes excess moisture. And again using the system is required for it to be maintained, not using it will reduces lifespan and then even if you save something on fuel you will have to put back in maintenance and repair work.

SeanR · August 12, 2022

Thank you, just read an article online that backs up what you say.

Ive heard of a re-gas but never heard of any aircon oiling.

Im assuming they will do this, should they do a re-gas.

Linas.P · August 12, 2022

8 minutes ago, SeanR said:

Ive heard of a re-gas but never heard of any aircon oiling.

It is done during the same process, if you look at the machine used for re-gas, or if they issue you with receipt (sometimes machines prints it), then it will say something along the lines - "recovered: 80g and 10ml. refilled: 120g and 40ml", the grams are the refrigerant, them ml are the oil and it is done during the same operation. And the process is usually works as such > remaining oil/gas recovered >vacuum is drawn on the system > then system is left for 15m and vacuum checked to make sure there are no leaks > and only then gas/oil is refilled according to what car requires.

Marlinleg · August 12, 2022

Linas.P I agree entirely 👏👏👏👏👏😍👏👏

Razor61 · August 12, 2022

4 hours ago, Linas.P said:

Faulty A/C compressor and or A/C clutch.

Had exactly the same problem. Some say A/C does not need servicing, but Lexus recommends doing it every 2 years. Again some say just keep it ON (which I agree with - it should never under any circumstances be OFF) and don't bother with service, but I rather pay £60 for re-gas and oiling every two years than pay £700 for new compressor and fitting.

I note you said you only used it twice - that is part of the problem, A/C should never be off, that causes seals to dry out (as oil circulates with refrigerant), then oil/refrigerant leaks trough dried out seals and once lubrication is lost or insufficient A/C compressor seizes. Not only that - having A/C off for longer periods of time just promoted bacteria growth and when you turn it on it not only stinks like swamp, but may be dangerous for your health.

In your case maybe it seized momentary on dry start, but luckily got some lubrication and started working again... that is not to say it wasn't damaged.

Great post with accurate and excellent advice. It is what an Automotive Aircon specialist will tell you, plus they will definitely tell you to use the aircon all the time to keep it in good working order and help prevent nasty smells and bacteria. The compressor is only engaged and working when it needs to.
The ‘uses more fuel’ thing is true but nowhere near as much as people think and is very little. The same as leaving a window or two open causing drag, that is what I was told.

Texas · August 12, 2022

‘Uses more fuel’, we’ll you don’t get something for nothing and prob be cheaper in the long run if you gotta buy/fit a new compressor🙄

LenT · August 13, 2022

I notice that Alex Robbins has some thoughts on aircon systems in today’s D Telegraph.

http://digitaleditions.telegraph.co.uk/data/1065/reader/reader.html?social#!preferred/0/package/1065/pub/1065/page/181/article/NaN

SeanR · August 13, 2022

Also, the short write up that backs up what has been said.

https://www.coolcaraircon.co.uk/using-car-air-conditioning-all-year-round/#:~:text=Let us find out how and why.&text=You should run your car's,to move around the system.

Passed all this info on to the misses and watched it go in one ear and out the other haha

SeanR · August 13, 2022

Ps, went out for a drive last night and put the aircon on.

The revs went up a little but no pulsing.

Im hoping ive got away with it, will see how it goes.

Thanks all.

Much appreciated

Linas.P · August 13, 2022

3 hours ago, SeanR said:

Ps, went out for a drive last night and put the aircon on.

The revs went up a little but no pulsing.

That is normal, when A/C is ON the idle raises slightly to compensate for extra load, because remember - idle is adjusted to be barely enough to keep the engine itself running . Once driving it usually no longer matters above like 5MPH.