The intake manifold gasket may develop and external engine oil or coolant leak. In some cases, an internal coolant leak may occur causing coolant to mix with the engine oil. Running the engine with a coolant/oil mix may result in engine damage. Replacing the intake manifold gasket should correct this issue.Google+
Car Problem Reports
Pontiac Grand Prix GTP Intake Manifold Gaskets May Leak Coolant or Engine Oil
Pontiac Grand Prix GTP Problem
Average Mileage: 119,797 mi (40,000 mi - 160,000 mi)
Visitor, 2004 Pontiac Grand Prix GTP
These engines generally do not blow the head gaskets. White smoke came out. I thought it was a blown head gasket, but the car only has 62,000 miles on it. It was the plastic lower intake manifold gasket. This one is the supercharged model. Get the metal gasket, do use the plastic ones as you will have the same problem later. Merle Gebers
Visitor, 2000 Pontiac Grand Prix GTP, 130,000 mi
CONSTANTLY ADDING COOLANT
Visitor, 2004 Pontiac Grand Prix GTP, 83,000 mi
engine leaking coolant and oil from intake manifold, car slightly runs hot in traffic and idling. changed thermostat, changed radiator cap,bled air out of cooling system,going to replace intake upper and bottom gaskets,this should stop leak, hope it solves heating issue.
Visitor, 2004 Pontiac Grand Prix GTP, 147,000 mi
Constantly having to add coolant, also had white smoke under hood. Found external oil and coolant leak. Cost of repair $1300
Visitor, 2004 Pontiac Grand Prix GTP, 80,000 mi
Losing coolant and oil, problems starting and a rough idle.
Visitor, 2004 Pontiac Grand Prix GTP, 47,000 mi
oil and coolant leaks, external,
Visitor, 2004 Pontiac Grand Prix GTP, 132,000 mi
I had my hose gaskets blow out and replaced them with metal instead of plastic had no problems since great car
Visitor, 2000 Pontiac Grand Prix GTP, 97,452 mi
oil in coolant but no coolant leaking into the oil
I have power steering fluid leakage since I bought the car but the problem is worse in the summertime. Now I have leaks in the oil gasket, and the man at the garage told me that it will probably get worse. Today I had brown smoke start pouring out from beneath my hood and thought there was a fire. It finally stopped and I am not sure what to do now. Don't know if I should even drive the car to a garage.
Visitor, 2000 Pontiac Grand Prix GTP, 142,000 mi
Leaking oil and coolant