[Nice Ride]

I've noticed that if the truck sits for a week or so without being driven, every now an then right after starting, there will be a loud clunk in the engine bay. I have to assume it is from the AC compressor. I always leave it set on auto. There is nothing else that I can think of that would make this sound. The truck is in park and it occurs right after starting. No noise after or right after a re-start. Will only occur if truck was sitting for a week or so.

 

[Punmax]

Best bet would be to get a sound clip of the noise. Also, try starting the truck without the A/C on and see if that makes a difference?

 

[JLeosnow]

Is it just one loud "clunk" or is more like a continuos chatter until turned off and restarted?

-John

 

[gloz28]

It could be the engine mount it makes the engine lift up and fall back down resulting in a clunk

 

[Nice Ride]

Just had rear mount replaced, was leaking. The problem happens right after the truck starts and the A/C compressor kicks on. It is a really LOUD clunk. No noise or vibrations after and will not happen again unless car sits for a very long time, week or more and will not happen every time . Each time it happens, the car is parked on level ground, still in park, and just after starting, within 1 to 2 seconds. It is more than likely the compressor, but it is fine with the exception of every now and then. Truck and A/C is fine otherwise.

 

[Nice Ride]

Its the A/C compressor. Will only happen if truck is sitting for a long tome without using the A/C compressor for a long period of time. No problems at all with the A/C.