Serpentine belt noise

The first thing that I would check would be the serpentine drive belt. When they get old, they tend to crack and stretch, reducing their grip on the various pulleys. At some point, they start squealing loud as heck on acceleration. It's the simplest thing to check. Here's a guide on the belt. It'll show you what to look for.

https://www.2carpros.com/articles/how-a-serpentine-belt-works

Start there and let us know what you see. Good luck!

Okay. The next thing is the pulleys. Take the belt off and then start the engine. Not for long, but just long enough to see if it makes the noise. If not, shut the engine off and feel the pulleys by hand. Look for one that wobbles or doesn't turn smoothly. That one is going to be your problem.

Use the image below to identify the pulley and also as a guide for putting the belt back on.

Here's our general guide on replacing the belt:

https://www.2carpros.com/articles/replace-serpentine-belt

Here are a couple of videos on changing the belt specifically on your car:

https://m.youtube.com/watch?v=
https://youtu.be/59eNu8vKOrI

Let us know what you find.

Yeah, that could be it. Looks like just an idler pulley. Easy to change. Just take the belt off, take off the bolt in the center of the pulley, and swap the pulley. By the looks of it, you'd have to do it with a regular wrench. Not sure on the size though. Probably a 13mm or something close.

Can you identify the pulley using the image below?

Also, I'd like a better look at that belt. I think I see some cracking, which would also cause a squeal.

Hello, I'm Danny.

Just here to add. It looks like a YouTube video was added for a Hyundai Sonata. I've added a few pictures below for a 2003 Mitsubishi Galant 2.4L. Does your power steering pump and alternator have these type of adjusters (circled in red) and not an actual spring loaded tensioner? Let us know after verification and we'll go from there. Hope this helps and thanks again for using 2CarPros.

Oops I added the wrong video. Guess I've got too many threads in my head. That belt needs replacing. No doubt about it. It's pretty cracked and is almost definitely the source of the noise.

Here's the correct youtube video:

https://m.youtube.com/watch?v=XLF1sXbh3iI

I wouldn't change any pulleys until you get that belt changed. It's very worn and stretched. Worn down belts like that one slip and make terrible screeching sounds. Change it and see what happens.

Hello again.

I looked online and a remanufactured alternator is about $150.00 USD. Here is a tutorial showing how to remove and replace an alternator and the serpentine belt:

https://www.2carpros.com/articles/replace-serpentine-belt

https://www.2carpros.com/articles/how-to-replace-an-alternator

I've attached picture steps below for alternator replacement on your car as well in case you want to go forward with this repair. Hope this helps and thanks again for using 2CarPros.

Danny-

Okay. A belt is roughly a $20.00 part and most cars these days are not at the end of their lives at 150,000 miles. But I understand if you are ready to move on to something newer. Either way, let us know how it goes and please do come back any time.