Issue when air is on and driving.

[994door]

When i have the AC on and im driving it runs a little weird. It is a 4.0 with 126000 and i have done the plugs wires and fuel filter all within the last 20000. I mainly notice it when on the freeway going about 70 it feels like the engine gets slowed down or loaded. I am a stickler and it bugs me, all the other fluids are toped off or changed every 3000. What does anyone think. Thanks

 

[robertoa1a]

I would think that this problem calls for A/C gauges. I am curious about the high and low readings and how it reads through the compressor cycles. High speeds usually work in the A/C systems favor due to all of the cool air passing through the condenser. Assuming the refrigerant pressure is normal, there is potential here for compressor going bad but not necessarily.

Remember too much refrigerant is bad too.

 

[994door]

last year my girlfriends car had no air so we bought one of the bottle things and charged it, we bought two bottles and i hooked it up to my truck to see what it was at and it was just below the top on the gauge so i dont think it is the compressor. well thanks for your input

 

[JDraper]

As the compressor kicks on and off, you will feel the motor 'stumble' slightly if you're running at a constant speed with light throttle. You're adding an additional drag on the motor every time it kicks on.

 

[994door]

yes it feels like that but only the air had been on. my comute is about 25 min. and it starts 5 as soon as i get on the freeway. air blowing the whole time. max air full blast. it does it too when city driving but not nearly as drastic. a guy at work said that it is the ignition. but that doesnt sound right.

 

[JDraper]

The compressor does not run full time when you have the a/c on. It cycles on and off as necessary, even with the air set to Max, so it will pulse pretty much all the time that it's on.