I have had my car into two different shops and they can see the leak from the bottom but can't find it so I am know turning to everyone here for some ideas that may help me find it and fix it before winter sets in. So the leak only happens when the car it running and it is leaking by the passenger side part of the frame rail. Both shop I had it at said it wasn't leaking from the water pump of the hoses along with the overflow reservoir. I replaced all of that stuff I mentioned when I went to flush out the Dex-Cool and change it over to a 50/50 system. Also I have had it just at an ideal to find the leak and never could but I could see antifreeze on the frame rail on the passenger side so I an know coming back to everyone for some ideas on what it may be so I can fix it. It seams like the leak is either coming from behind the harmonic balancer or a little bit higher up right around the belt tensioner setup but not really for sure. I have had a a few friends say it may be a freeze plug behind the timing cover but accordantly to GM a 3.1 V6 don't have them behind the timing cover, they just have the gasket setup and they thing it may be a bad gasket but not really for sure. So what does everyone think if may be. I am open to any and all ideas. Also it leaks about a half of a gallon of antifreeze a month so I always keep a jug in my trunk.

Also here is a few more details I forgot to add. The first one is that the leak stops when you turn off the car but if it is moving up and down the road or just idling it will leak so go figure. Last but not least is that all of the antifreeze collect on the passenger side frame rail and no where else. Also I wanted to mention it isn't a leaking heater hose because they are on the driver side of the car. Also with the leak the car does overheat of affect the heat in the car, the only thing that is is doing is making me half to but antifreeze ounce a month so the car won't overheat.

I was doing some research and I a ma wanting to know if everyone may think I am right on this but could one of the coolant ports on my timing cover be leaking. So what do you think on that.