After my 2007 corolla runs for avout 20 minutes, when the car is in motion, I hear a "pinging" noise. It is similar to the last kernals of popcorn popping in a pot or the noise you hear from under the hood when you turn a car off. The noise is not evident when the car is stopped. It does not really increase in intensity with an increase in speed. What can this be? thanks.
Jan 24, 2013 at 8:11 AM
