My 2010 lt with a 2.2 liter has begun making a screaming noise on acceleration. I changed the belt and tensioner. The sound changed from a squeal to a more mechanical scream. Not as loud as the squeal. The alternator feels ok by hand, no play in the shaft ,no noise turned by hand. Anybody have any ideas? I still LOVE this car.
lmilage is 155000

 

Check the exhaust flex pipe. I'll bet it's bad/cracked.

 

It was my cats clogged. I changed them and the O2 sensors and it runs fine. Will the engine light go off by its self?

 

What engine light? You didn't bother to mention one.

 

Try a battery lobotomy.