I bought a 2007 mustang a few weeks ago from a dealer, 88k miles. the first week everything seemed fine. Now I have a squeaking noise that comes up as soon as I turn my car on.

It squeaks for about a second or two then nothing, another few seconds the squeak comes back, then goes away, and this is with the car in park just turning the car on. The squeaking does get a bit louder as I let the car sit and warm up.

This also happens when I'm driving. the squeak comes on then goes away and does that over and over. I actually pressed the gas pedal down pretty car yesterday and it sounded like the squeak was very loud and stayed squeaking until I stopped giving it gas.

Seems to happen more when I accelerate. Can't post a video tonight. But if needed I'll post one tomorrow. Anyone ever have this issue? I live in Ohio and it is pretty cold here, Snow on the ground. If that effects anything.

From popping the hood and trying to pin point the area the squeaking is coming from it seemed like it was very close to the alternator.

 

Check the plastic idler pulley. They tend to fail.

 

Every time I develop a 'squeak' in any car it's the belt 9 times out of 10. If it is the original belt, 7 years and 88k miles is quite a bit of use. Time to change.

 

I checked my idler pulley and there is a bit of play in it. I can move it a little. not much but It does wiggle and when turning on the car and listening for the squeak it seems to be coming from that. the idler pulley also wiggles a bit with the car turned on. seeing how they are about $30 should i just go ahead and replace it and see it that does the trick?

It doesn't seem like a hard job.

 

I had a squeak that turned out to be the power steering pump ...

 

Note the numbers on the belt, whether they're facing you to read or not, so you'll reinstall the belt in same position. Remove belt, spin each idler pulley by hand slowly and fast, feeling/listening for rough bearings. The grease can dry out over time and cause noise and bearing wear. The bearings can have the slightest amount of side play but not a lot. I just had noisy idler bearings on my F150 when it was -35. Being cheap {lol} and having no stores open when I did this, I removed them, popped a grease shield out on each, washed the old bearing grease out. Then I checked the bearing for roughness. They were ok so I re-lubed each with wheel bearing grease, reinstalled shields and reinstalled idlers. Noise gone. Should last for awhile.


You can also check the V-grooves of the serpentine belt and look for debris that might be jammed in a v-groove.

These are just some things to look for before spending money on parts.