Pontiac Repair: low coolant, intake manifold gasket, upper intake manifold

Question
I have a 1998 Pontiac Grand Prix SE

This summer I had to replace the Water Pump and A.C clutch.  Since then (4 months later, then about 3 months then 3 weeks) I had to refill the coolant res.  Twice the low coolant light came on so I filled it up ASAP.

Oil does not look milky nor does white smoke come out of the exhaust, What should I be concernced with? Did not see a leak in upper or lower hose, did not check heater coil hoses yet.

Answer
Hi Kevin:

What engine is in this 3.8 or 3.1 V6? The 3.8 engine has issues with the upper intake manifold pleniums leaking out the rear under the throttle body and on rare instances external lower intake manifold gasket leaking. If it's a 3.1 the lower intake manifold gaskets leak all the time both internal and external. The internal is what you don't want to happen at all! they usuallyt leak out the rear corner first uner the throttle body area. from time to time they have external head gaskets leak out from the rear head. Those are the most common issues with either engine. If you loosing enough of it that the light is comming on and the overflow bottle is empty that a problem. Hoses usually do not go bad on thse cars and very very rearly do heater cores or radiators leak any more. Good luck :}