Hey guys. Anybody know what could cause my 2000 grand prix gt to suddenly start sounding really loud upon starting and idling? Started about a week ago. Sounds like an exhaust leak would sound or bad catalytic converter but that isnt the case. I pulled her up on ramps and crawled underneath with flashlight and inspected. Sound is mainly towards front of car. I also noticed a little coolant around the area where air intake body is. Anybody got any ideas?