Jim Shorkey Youngstown Chrysler Dodge Jeep Ram Fiat

took my liberty to them 2 times for a vibration. all they did the first time was lower my tire pressure and tell me it still had a high speed vibration but to try it with the lower tire pressure. just brough did the first time was lower my tire pressure and tell me it still had a high speed vibration but to try it with the lower tire pressure. just brought the lib back to them now they tell me that i have cupped tires in the front and thats what is causing the vibration. thing is they were new tires when i first brought the car to them. i'm sure the lower pressure had something to do with the cupping. now not only do i still have the vibration i have to purchase new tires again. i keep getting the run around with this vibration. also have a rough idle. they told me chrysler only puts copper spark plugs in their cars and they only last 30,000 miles. rough idle has been ther since i bought the lib with 12,000 miles on it. another dealer told me injectors may b gumming up. my car only has 28,000 and still is under warranty. More