My son and I have a '85 Camaro Berlinetta with a 2.8 (father/son project - he's 17). It runs pretty well, all things considered and looks good. It sometimes makes a growling noise when not moving - you're sitting at a traffic light - transmission (automatic) engaged. Put it into neutral - sound goes away - so it appears to be transmission related. Idle is set at about 750 rpm. Any thoughts out there?

You can tell by the name I'm a British car person(1972 tr6), but really enjoy this camaro and working on it with the son.

Thanks.