2002 SE leaking coolant

My 2002 Grand Prix SE has about 106,000 miles on it. For about 4 years, it's had a small coolant leak that's gotten a lot worse lately. I'm adding about a gallon and half of coolant every 4-6 days.

I cannot tell where the coolant is leaking from but when I look under the car, I can see drops coming off the cross members under the engine on the right side. I can't see any coming from the radiator or the hoses that connect the radiator to the engine.

Where might it be leaking? I've been told my others that the 3.1 litre engine has a tendency to leak from the "lower intake." Where is that?

Also, why does the low coolant light go on even when the reservoir is filled up?

Thanks!

The intake manifold is the big aluminum piece that is in the center of the engine between the valve covers. The factory gaskets are plastic and on teh GM 3100 engines, they all fail sooner or later. With the amount of coolant you are using, most likely you're going to need head gaskets as well. On the reservoir issue, when the intakes go, it won't allow the system to properly pressurize. It is negative system pressure that draws coolant back into the engine from the overflow. That is why the overflow stays full even when the radiator is low.

Agreed, LIM gaskets are probably your issue. Look down under the throttle body with a flashlight. Seen and coolant, or black stains. Then look on the other side behind the power steering pump.

Also take your oil cap off and look at the bottom. Have a gunky tan build up on it?