Rattle from under front of vehicle when AC on

[dankoos]

Been hearing this rattle, almost a buzzing when the car is first started and the AC is on. If I turn the AC off while still in park, rattle goes away. Also seems to go away once I start driving (at least w/ the windows down I don't hear it). Rattle best heard when I get my head down almost under the front of the vehicle.

2013 Explorer Limited, 110k miles.

Some sort of AC compressor issue? My wife drives the car 90% of the time...so when I drove it lately, not only did I notice this rattle, but the AC seems to take a while to cool down...do modern vehicle AC systems still need "recharged" from time to time?

As you might be able to tell, not much of a car guy.

 

[xartic]

There's a thread on here discussing this. I had this issue with my recent purchase of my 2014 and just replaced the belt with a 45.375" length one, and the one Advance Auto sold me was a 45.74" which is made for the PIU with the 200A alternator.

I replaced both the tensioner and belt at the same time and my issue exactly like yours, is now non existent.

 

[dankoos]

There's a thread on here discussing this. I had this issue with my recent purchase of my 2014 and just replaced the belt with a 45.375" length one, and the one Advance Auto sold me was a 45.74" which is made for the PIU with the 200A alternator.

I replaced both the tensioner and belt at the same time and my issue exactly like yours, is now non existent.

Stupid question, what is the "tensioner" and what does it have to do with the AC? Is this the "pulley" that the serpentine belt attaches to for the AC? I almost certainly will not try this on my own, but always MUCH easier telling the mechanic what I think the problem is so they can check that first rather than taking forever diagnosing and I like to understand what I am describing.

 

[peterk9]

I believe this is what xartic is referring to; Belts & Pulleys for 2013 Ford Explorer | Auto Nation Ford White Bear Lake

Peter

 

[dankoos]

Been hearing this rattle, almost a buzzing when the car is first started and the AC is on. If I turn the AC off while still in park, rattle goes away. Also seems to go away once I start driving (at least w/ the windows down I don't hear it). Rattle best heard when I get my head down almost under the front of the vehicle.

2013 Explorer Limited, 110k miles.

Some sort of AC compressor issue? My wife drives the car 90% of the time...so when I drove it lately, not only did I notice this rattle, but the AC seems to take a while to cool down...do modern vehicle AC systems still need "recharged" from time to time?

As you might be able to tell, not much of a car guy.

So the noise went away for now, but here is what tensioner looks like with engine running. Should it be wobbling like that?

 

[xartic]

So the noise went away for now, but here is what tensioner looks like with engine running. Should it be wobbling like that?

I don't think it's suppose to shake like that but I would replace both the belt and tensioner at the same time. I also recommend getting the correct belt for you 175A alternator, which differs from the the higher amperage that's offered.