On these last few days, which have been the hottest this year, my A/C (2003 Civic Si) has begun cycling between cooling and just blowing air. It only does it in the hottest part of the day (95-99 degrees). When the temperature drops a bit, it works fine. Temperature gauge doesn't move, coolant level is OK.

I tried doing the troubleshooting check that was posted in an A/C-related thread on Page 3 of this forum, but it didn't give a response anything close to what was posted.

Is this probably just low refrigerant? How do I go about recharging the system? I looked at the recharge kits at the parts store, but I'm not sure about just what to get.


Thank you.

 

As it gets cold sometimes, you have enough refrigerant. No need to add more.

Probably the problem is the compressor clutch gap being too wide. When it is not cooling, pull over and look under the hood and see if the compressor is engaged.

 

Thanks for the info.

Can I see the A/C compressor when looking into the engine compartment from the top, or do I have to get under the car? What exactly would I be looking for to see if the compressor is engaged? Can I adjust the clutch gap?

 

I think you can see the compressor from the top. You want to look at the plate that is right next to the pulley. The pulley spins all the time the engine is running, but the plate will spin only when the compressor is engaged.

Also while you're looking after it quits cooling, see if the condenser fans are on when the system is supposed to be cooling. If they are not there is a different problem.

With the compressor disengaged there should be a gap of 0.020 inches (0.5 mm), or less, between the plate and the pulley. When the gap is too wide, the electromagnet coil will have trouble pulling the plate into the pulley. This gets worse at high temperatures under the hood because the magnet loses strength.

The gap can be adjusted by removing the shaft nut in the center, take the clutch plate off and remove some shim washers from the shaft. This can be done with the system still charged though you may need to unbolt the compressor from the engine to get clearance. Do not disconnect the refrigerant lines and the system will stay charged.

 

Does the condenser fan run when the A/C is on?

 

I actually discovered this thread by accident as I was doing a google search!

Same situation here; compressor cycles on/off too much, irrespective of day or night. During the night I don't feel it too much. But during the day it should stay on constantly so that cabin temp can go down faster. But it doesn't, it cycles even more frequently if I'm accelerating. It hardly ever cycles when the car's parked.

So what's the ultimate solution then? Adjusting the clutch gap? I've already had the clutch replaced once BTW. And, I've had my AC system checked up at three different dealers/shops. They say it's OK.

 

Please quit opening new threads about the same problem!