So something that bothers me about my car, is when its cold (i mean completely cold only) until its near full operating temp, at about 1300rpm its makes a coo-ing type noise. I tried to record it on my phone. Can anyone tell me what it is? Its nothing bad, but its kinda embarrassing when your driving a v8 that does this! and Is there something I can do to stop this? Its a stock engine/exhaust system at the moment. Although will get piggies/exhaust done soon.