AC makes noise when it turns on

[BlackKnight]

I've noticed this loud thud when I initially turn on the AC, probably from when the clutch engages and it turns with the belt. I can hear it very clearly and it sounds like a rock has hit the firewall really hard. It's really loud when I turn it on while I'm driving but not as loud when I'm sitting still and I turn it on. It doesn't make any noise when it cycles under operation. So now I only turn it on when sitting still but is this normal? Is it an indicator of something to come?

 

[Wifey]

Have your Freon / pressure checked, I have 2 vehicles that do the same thing, usually after having them serviced. The ford F-350 is the worst offender

 

[dragon]

this may be the recirculation door if your doing this under 3/4 or full blower on.

 

[BlackKnight]

Have your Freon / pressure checked, I have 2 vehicles that do the same thing, usually after having them serviced. The ford F-350 is the worst offender

I'll have this checked the next time its in the shop.

Dragon,
I always have the fan set on the lowest setting when I turn on the AC and still get the loud thud noise. Since I get the noise when I'm driving, could it be the fact that with the belt moving so fast and then all of a sudden the clutch engages, going from not moving to however fast the belt is moving, the noise is from that?

 

[Roz]

Mine did it a few times. I'm fairly sure its something inside the blower box. . . Dragon's hypothesis sounds about right. It sounds like a mechanical door or something is getting hung up.

 

[wyoramsrt-10]

Both my dodges do this. It seems to not be as loud if I let the fan run for a little bit then hit the ac button. Still a very disturbing noise.

 

[BriteCrawler]

Both my dodges do it also.

 

[AWDisuzu]

mine too. at least on mine, it's the compressor clutch kicking on.

 

[Chuck B]

Its your recirculation door...... been there heard/felt that one. Leave it off or like Dragon suggested dont have blower on full when you turn it on or if always on when you first start the truck.

 

[Roz]

Its your recirculation door...... been there heard/felt that one. Leave it off or like Dragon suggested dont have blower on full when you turn it on or if always on when you first start the truck.

Forgot to mention, this is what i do. That "fixed" my problem.

 

[Niz]

I have the same problem. It has gotten progressively worse. Started out sounding like something was loose and over time it is getting looser and looser. Chrysler says they are aware of the problem but dont know how to fix it. Imagine that??!!??

 

[TheMoparConnection]

these vehicles along with the diesels have a harsh a/c engagement. there is a flash for the diesels to help it, although nothing yet for the srt-10's