Keep taking it back and make them figure it out and fix it. I don't know what it is. Especially since I can't hear what you're hearing. Sorry, wish I could help. If they keep screwing around and not getting it fixed make them give you a new car. Check the lemon law for your state. Alot of times if you take the car in at least 3 times and it still doesn't get fixed after being worked on those 3 times you can claim the car as a lemon and get a new one from the dealer.
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FOR SALE: 1996 Mustang GTS: 5-speed, K&N, removed air silencer, 3.73s, 48,000 miles. $11,500
http://www.mustangworks.com/cgi-bin/moi-display.cgi?388
[This message has been edited by 96GTS (edited 10-23-2000).]