THE INTAKE GASKETS ARE BAD. THE LEAK WILL SOON START INTERNALY AND YOU WILL NOTICE THE OIL WILL LOOK LIKE A BAD MILK SHAKE. REPLACING THE GASKETS REQUIRES TAKING THE INTAKE OFF THE ENGINE, REMOVING THE VALVE COVERS AND THE ROCKERS AND PUSH RODS. THE COOLENT LINES RUN THROUGH THE INTAKE SO THE COOLENT MUST BE DRAINED AND THE ALTERNATOR AND Power Steering PUMP HAVE BE LOOSENED SO YOU CAN GET THE VALVE COVER OFF. ALSO THE COIL PACK AND SOME OF THE EGR STUFF HAS TO COME OFF TOO. GET A CHILTON'S BOOK AND GOOD LUCK.
Check to see if there is coolant on the engine block. It is common for the Monte Carlos, along with other GM cars equipped with the 3400 V6 engine to experience leaking intake manifold gaskets. A leaking intake manifold will cause oil to leak into the coolant system and even worse, for coolant to leak into the oil system.
It's probably a head gasket problem.
The low coolant sensor is bad or disconnected.
thermostat gasket probably leaking. replace thermostat and gasket making sure that thermostat housing is flat.
I would suspect the manifold itself is leaking around the cooling passages. It will need to be removed and the gasket replaced.
Coolant leaking onto the floor of the passengers side or out drain tube for a rupture no heat for a blockage.
This is either the heater core leaking coolant or the air conditioning drain line is plugged. If the water tastes sweet on your tongue or is warm it is from the heater core.
Don't confuse engine coolant and air conditioning refrigerant. Engine coolant is Dex cool- Do not use any other kind as the sensors in the system will read differently with the wrong coolant and make incorrect adjustments in your system. Air conditioning refrigerant in your car is R-134a.
has the red coolant in a 2005 monte carlo been changed since reports on it deteriorating the head gasket?
Check your coolant level...
If coolant full could be a bad sensor
how to remove the engine of the 2001 monte carlo step by step