Does Your Is Loose Much Power When A/c On?

[ridgersIS300]

As the title suggests, I know that a car will generally loose around 10% of power with the a/c on, however when mine is on it seems to loose a lot more. Anyone else experience this, particularly with the IS300??

[The Transporter]

If you are genuinely losing 10% then you have issues with your air conditioning.. Has it recently been recharged?

[ridgersIS300]

Yeah it had a full a/c service at Lexus about 18 months ago?!?

[The Transporter]

Either it is overcharged, has air in the system or your compressor is starting to sieze..

[ridgersIS300]

how would I know if the Compressor is starting to seize, would it really cause power loss?

[The Transporter]

With the engine off grab the clutch plate and turn it.. it should be free and smooth and silent... If it feels like it is grabbing or it is stiff, then it is on its way out... It may also be a bit noisy when the aircon is running with the engine on though these compressors can be a little rattley.

If a leak sealer has been used then blockages can produce high pressures in the system.

Any undue pressure or drag in the system or compressor will cause a greater strain on the engine so the engine has to work harder to drive the air con.... I cannot feel the compressor cut in and out on my IS200 but it can be heard at tick over.

Who serviced the air con and how did he do it? how much refrigerant and or lubricant did he add?

[ColinBarber]

10% is about the maximum it would affect economy when running, probably a bit less.

With climate control it is normally cutting in and out so the overall impact is less. If your system isn't putting out nice cold air then it has to run for longer, this makes older poorly maintained systems less efficient.

[esp]

I Would try a Regas before doing anything else most fast fit centres do regases for £50

[The Transporter]

Or alternatively take it to someone who knows what he is doing with car air con..

[ridgersIS300]

Some great advice cheers guys..... Transporter you are prob right, what do I go in for - an a/c health check or something similar?

[The Transporter]

You are probably best contacting a reccomended auto aircon specialist and simply explain that you felt that the airconditioning was causing considerable drag on the engine and could they check it out...

Personally speaking I would check how the compressor felt, check that the correct, uncontaminated refrigerant was used with my refrigerant analyser, attach my gauges and run the system at about 2000RPM noting the high and low pressures. check that the electric fans are working and that the condenser isn't clogged with road debris.... Then I would decide what my next course of action would be

[ridgersIS300]

Crikey.... Not anywhere near derby are you? Lol. Seriously though really appreciate the advice

[The Transporter]

I'm afraid not, I used to do a lot of car air con but now only do it for friends and family, modern car ACs are so cheap and nasty they are more grief than they are worth, plus I got cheesed off by folk phoning up for the price on recharging a scrapper saying that the cowboy up the road can do the job for £30 can I beat that price. The refrigeration system on the IS is a good, simple and robust system