I have an '09 Unlimited that has been squealing when I start it up. I noticed it a while ago but it was less frequent. In the last couple of days, it has happened almost every time I start it. Any thoughts out there JK world... Thanks!

 

Classic sign of either a bad belt or a bad bearing, likely on the water pump. Does the pitch of the squeal change with rpm?

 

Same questions as Rob. I had an issue where the starter wasn't fully disengaging the flex plate on start and made a god-awful grinding cat dying metal on metal noise. If the noise sounds like that and then goes away. Might be the starter is crunk.

 

I've not had this issue yet on JK, but from several other vehicles I've had to replace it on.....I'd take a look at belt tensioner pulley to start. If you relieve the tension and pop the belt off, you should be able to give the pullies a spin with your finger and spot the bad one very quickly. More often than not it's the tensioner pulley.

 

maybe try some belt dressing first????

 

If it is the tensioner pulley, looks like you can replace the pulley itself for $17.....whereas a lot of times you have to replace the full tensioner unit. Even then, the unit is <$50.

 

What others have written. Just wanted to add that one of these can be your friend when tracking down noises ...

https://www.amazon.com/Lisle-52500-M...7s+stethoscope

 

I have seen this a couple of times on other vehicles and it can be the A/C clutch.