I have a 2002 neon with around 72000 miles on it. recently when it gets to be a bit cooler the trans starts knocking when i put it into reverse. I havent flushed the trans so i'm kinda hoping that wat it needs is a flush or something minor cause it runs great. COuld it also be the PCV valve? that hasnt been replaced either since i bought the car in 2003 and then it had around 25k on it. Thanks for your help

 

Same thing happens with my neon and I haave 71000 Miles i've brought it in to Dodge 4 times they keep telling my theres nothing wrong with my car.