2006MustangGTNYC

I took the car for an hours worth of drive today. When I bring the car home to park, I notice a ticking sound coming from the engine compartment. I wait and I hear it again. So I turn off the car and come back to it 30 minutes later and the same thing. So I have a look under the hood with my flashlight and I notice that the ticking sound is coming from the bottom left pully. Every 5-25 seconds, it stops spinning and starts spinning again. (pic of pully in question highlighted on pic)

After close examination, I noticed that it ONLY spins when the climate control nobe is in the "windshield/foot" position. When it is in the "front dashboard/foot" position it doesnt make the ticking sound (start-stop of the pully)

I then tried the A/C and it's the same with the A/C. Is this something to worry about? Is this normal? I never heard it before.

I'd like to add one more note: I examined the belt and it seems fine. The belt spins and there is nothing lose.

2006MustangGTNYC

anyone?

Newbreedgt05

That the A/C compressor. It cycles on and off every few seconds. The ticking sound that you hear is it turning off and on. It is completely normal. On most newer cars the A/C compressor automatically comes on when you select any of the window defogger positions. That's why you only hear it when the A/C is on or the climate control is in the window position.

2006MustangGTNYC

But I never heard this before or is it that it was always there and I never noticed it?

Does this happen to your car?

Sleeper05

the click is the a/c compressor's clutch activating. i was woried about it too once, but it is a normal thing. if its too annoying, just drive with the windows down and the a/c off

2006MustangGTNYC

No, it's not that it's annoying, I just need to know if its normal. I have a 2006, barely 1000 miles and this just started.

Are you guys sure this is a norm?

MikeVistaBlue06

Yep. It is the A/C compressor. It has pistons and valves in it like our cars. If the sound you hear is rythmic, then what you are hearing is the pistons going back and forth in the compressor and its valves opening and closing.

Unless it is making a grinding or squalling noise, what you describe is normal.

An air compressor will make the same noise...only a lot louder!

Hope this helps.

Mike

2006MustangGTNYC

What do you mean "like our cars?" I have the same car. The sound that I hear is it turning off and back on every 5-20 seconds when it's in the windshielf/foot position or A/C is turned on.

I'm supposed to take a drive down to evolution performance tomorrow and he read this and told me it's not normal and to get it checked out before slapping on the parts that I want. So I have no idea what to make of all this unless everyone replies and says "yes, this is happening to my car too"

MikeVistaBlue06

The compressor has pistons that move back and forth as well as valves that open and close in sync with the pistons, just like our car's engine has pistons and valves that do the same thing. That's what I meant. Yes my car makes a similar noise.

All cars with an A/C compressor that cycles make similar noises. There are temperature sensors and Freon pressure sensors in the AC system. When they detect the temperature of the evaporator (unit inside the car that cools), reaches a certain setpoint (like 33°F) or a certain Freon pressure that usually means 33°, the computer in the car tells the compressor to switch off. When it warms to a certain temp or raises to a certain Freon pressure, the compressor comes back on.

If you turn your A/C wide open (fan on high and recirc), the compressor should turn on and stay on (if it is warm enough in your area).

I think your car is OK to drive.

Hope this helps.

Mike

2006MustangGTNYC

I Live in NY, I never use the A/C. The only thing I use is the heat and that is making the a/c compressor turn on and off??