Overheating 2000 Oldsmobile Alero 2.4 GLS

Oldsmobile Alero

Now it’s overheating

Car was running fine until I changed the radiator hose that was leaking. Now it’s overheating and I’ve replaced, thermostat, reservoir, flushed the system, checked radiator, I’m at a loss. Someone suggested water pump but if it was the water pump why would the car not overheat with a leaking hose but once fixed it began to overheat? It has to have something to do with some type of ventilation the hole in the hose was giving the system. I have also “burped” the system several times.


Make certain all leaks are fixed. Make sure coolant level is full with 50/50 mix. Straight water or coolant will cause the engine to overheat. No thermostat or stuck thermostat will cause an engine to overheat. Something to consider is one of the caps is bad since it does not overheat with a leak. Replace radiator cap and or overflow cap.

Cooling System Refilling Procedure


When adding coolant, it is important that you use GM Goodwrench DEX-COOL™ coolant. If coolant other than DEX-COOL™ is added to the system, the engine coolant will require change sooner: at 50 000 km (30,000 miles) or 24 months.
•Close the radiator drain cock.
•If previously removed, install the engine block drain plugs.

When installing the drain plugs, use pipe sealer GM P/N 12346004.


On vehicles equipped with the 3.4L engine, open the coolant air bleed valve. The coolant air bleed valve is located on the top of the thermostat bypass pipe/heater pipe assembly. Close the valve once a continuous stream of coolant is expelled from the valve.
•Fill the surge tank to the base of the filler neck.
•Start the engine with the pressure cap off. Run the engine until the upper radiator hose starts to get hot.
•If the coolant level in the surge tank is low, add the proper mix of coolant until the level reaches the full cold line.


After servicing the cooling system, and if the vehicle is equipped with an intermittent low coolant light, an occasional low coolant light may be encountered during some extreme driving maneuvers. This complaint should be eliminated by removing the surge tank cap and adding coolant to a level just at or above the full cold line when the system is cold.
•Install the cap onto the tank with hand tight pressure.