Hello Everyone,

Long time reader, first time poster. I have a 2004 Ford Ranger XLT (2wd, 6 cylinder, 3.0 liter). I've noticed that when I have the heater on (specifically on the "window defrost" option), I often hear a clunk noise in the front (right-side). This noise only occurs once, it does not repeat. It only happens when: (a) I am slowing down (5 mph or less) or (b) accelerating (5 mph or less) and (c) when the heater is on.

The noise occurs about 5 or 10% of the time I accelerate/slow down. Again, I think it comes from the right side...but I know how sounds can be difficult to locate.

I wish I could describe the noise better, but it really just sounds like "clunk." I don't know very much about automobiles, so any help diagnosing this noise would be greatly appreciated.

Thanks,

Dave

 

x2! I wonder the same question. Mine does this "thud" or "thump" from the right hand side when the defrost is on...but on mine it only happens within 1 minute on startup. I can actually feel the thud.

 

Compressor turnig on or air vents closing and opening??

 

The A/C compressor cycles on and off when the heater control is in defrost mode.

 

It sounds like something that I don't have to worry about.