what's with the loud a/c compressor thump?

[shendren]

i hear it on the 04. 5 and i heard the same thing on the 04 ford pos.



i didn't hear it on the 96 ctd. i am suspecting this is due to the 96 being significantly louder and drowning out the "thump".



anyone else notice this? thanks. scott.

 

[Bill Stockard]

Yep, my '03 does it and so did my '00 3500 CTD. Our '00 GMC Jimmy does the same thing so it isn't an exclusive Dodge feature!



Bill

 

[e-man-da-warranty-man]

Yeah I have the thumpin' ac clutch too. Seems to only do it the first time the compressor cycles after not being used for a week or so. I guess its normal eh?

 

[rbattelle]

Oh man, sometimes I swear that compressor is going to go shooting out the side of the truck! Sometimes it's quiet when you turn it on, sometimes it just EXPLODES!



At first I thought it was because it's a really heavy-duty compressor. Now I just think it's poorly designed (since the A/C doesn't seem to put out sub-zero air).

 

[MCornwell]

Its normal and its caused by unequal head pressure on the



compressor pump... most pronounced on the first engagement of



the pump.



-Mitch

 

[04 Diesel Power]

Mine does it too. So this is a normal sound?

 

[mberry]

Mine does it every now and then too. Usually when the engine is cold and has not run in 12 hours or more.

 

[moel]

mine does it - only when first engaged

 

[nickleinonen]

mine also does it...



i can't wait until the magnetic fluid clutches for these things go into production. seen a demo of it on tv [was a ford demo though] and the clutch engagement was silk smooth as it slipped slower up to speed making a smooth transission from not turning to turning. uses the same type of magnetic fluid goo as some sports cars have with the magnetically adjustable suspension stiffness [corvette i think was one of them]...

 

[lschultz]

Its the nature of the Dodge Cummings sort of like the belt chirp like the ole Harleys use to mark there spot. Like man :-{} and woman.