About 3 seconds after I start the engine in the morning I hear what sounds like a metal on metal grinding sound. It only happens on initial start up, later in the day no problems.
I took it to the dealer and we narrowed it down to the A/C compressor. There was a visible vibration in the unit and connected hoses.

The service manager found some piece of literature that said it was a common trait of these vehicles and to suggest that the customer turn the A/C off before leaving the vehicle for the night.

Now, I've heard that you should always turn the A/C off before leaving the vehicle, but this sounds more like my wife grinding the gears of my F150.

The truck is an 04 XLT with rear air and the 5.4 liter.
If anyone has any experience with this "common trait" please calm my nerves.

 

Hello,

My wife's 03 Eddie does the same thing. The way it sounds there should be metal shavings all over the ground. I got the same B.S. answer from my service manager. Just turn off the A/C. They are probably counting on it lasting past the 3/36 warranty.

It only does it every once in a while like you said so who knows. Our A/C smells like the intake vent is pulling out of the elephant cages at the local zoo, so I haven't thought much about that problem until it happened last night.

 

Our '04 does the same thing- only at first start- and only occassionally then. Based on posts like these, I've not bothered to take it into the dealership.

The part about turning the A/C off to 'prevent' this event is utter BS. The compressor makes the same noise whether the system is off or on when you last turned off the truck.

 

My 99 has always done this, especially when it has not been started for several days. I usually turn the AC off, and restart it after the engine RPM's have settled down after a cold start.