A/C. Is this normal?

[Stuttgart]

I've just bought my 2002 5 speed manual Boxster (986) from my partner who put 27,000 Km (16875 miles) in 5 years. He changed the evaporator because of leakage about a year ago. The A/C is working fine, lots of cold air even in the hot an humid days of the Caribbean where I live but...... when I suddenly press the accelerator pedal it kicks out the compressor for like 5 seconds and then kicks back on again, runs ok until I press fast on the pedal when kicks out again and so on. At first I thought this could be a feature for having all power when you need to accelerate fast (passing another car for example), but now I don't know. It does it even at idle: say you're stopped in a red light, you feel the compressor is on and cold air is blowing, then you rev it for a moment let it back to idle and about 5 seconds later you hear and feel the compressor kicking on again (meaning it went off while reving) and remains like this until you rev it to reassuming your drive. When I'm on a constant speed it does not turns off the compressor, thats why I have good cold air.

Is this normal? Low refrigerant charge and pressure switch taking out the compressor?

Thank you guys and girls in advance for your imputs

Rafael

[White987S]

Sounds normal to me.

[pk2]

... The A/C is working fine, lots of cold air even in the hot an humid days of the Caribbean where I live but...... when I suddenly press the accelerator pedal it kicks out the compressor for like 5 seconds Rafael

Ditto, I think anaysis is correct. Surprised you can hear it though.

Regards, PK

[Stuttgart]

... The A/C is working fine, lots of cold air even in the hot an humid days of the Caribbean where I live but...... when I suddenly press the accelerator pedal it kicks out the compressor for like 5 seconds Rafael

Ditto, I think anaysis is correct. Surprised you can hear it though.

Regards, PK

Well, in fact I don't hear the compressor but the difference in the motor sound. I know is very subtle but it can be heared as well as the sound of freon passing thru the expansion valve in its way to the evaporator. Plus the tach shows a short change in rpm's when it goes on again. You can also feel it: a bit warmer air for 30 sec or so.

In slow traffic it doesn't matter, but when you're in the road shifting fast and frequently the time the compressor is off rises significantly so the cooling capacity is diminished.

[stickshiftnz]

With many (most?) cars these days, the compressor cuts off when accelerating (or if the engine thinks you are) often via a vacuum solenoid, so the compressor does not sap any power. When overtaking, you need all the juice you can get. Even more critical for small, low-powered cars, where you can really feel the difference.

[Stuttgart]

With many (most?) cars these days, the compressor cuts off when accelerating (or if the engine thinks you are) often via a vacuum solenoid, so the compressor does not sap any power. When overtaking, you need all the juice you can get. Even more critical for small, low-powered cars, where you can really feel the difference.

Sounds absolutely logic!

I'll buy that answer

Thanks

Rafael

[RFM]

If you can hear the passing of the gas, it means that the system contains a to small quantity of gas.

[White987S]

If you can hear the passing of the gas, it means that the system contains a to small quantity of gas.

RFM, I thought this too, when I read his post, but he also states that the car is cooling properly. So, how does this shake-out?

[RFM]

The frequent on - off cycle of the compressor in combination with the gas noise confirm my opinion, too less gas.

The system contains enough gas to stay active, for example a full system contains 0,850 Kg ( 850 Gr. ) if there is a leak somewhere and there is still 0,600 Kg. in the system, than you got this symptom, once the capacity drops to 0,450 Kg. the compressor cut off.

[dave944]

I agree, but might also check the vent temperatures (on the highway) with a dial thermometer to see how cold things are really getting. As I recall upper 30's F for an R134 system.