I have a 99 oldsmobile alero 2.4 engine. it froze up. i drained it after it thawed and filled w antifreeze and water. now its overheating and heater is blowing cold air. what could be wrong?

Located on the very bottom of the radiator is a Large hose and the Drain Valve is there, open the valve, drain all the fluid, open the top of the radiator, hold a running water hose to fill the radiator, start the car find the balance of water flow, in the water hose and the drain. When the engine is warm about 3-5 minutes. It will then start cycling through the engine you may need to increase water hose flow now to keep the radiator full. Flush for 2-3 minutes or until crisp clear water is draining from the Drain valve. Turn off the car let all water drain completely. Then fill with Coolant. Water mix of 50%/50% coolants are suggested for summer time operation.
GoodLuck!!!

Very serious.... don't over heat too much or your car will break..... could be the thermostat is hooped... or the water pump.... make sure the car is completely thawed.... but i'd she over heats take her to the mach.... night cost a few bucks but no car costs a lot more

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1999 oldmobile intrigue over heating. Heat not blowing hot

buy a flush kit from Walmart, about 5 bucks. cut the top heater hose add the kit hook-up water hose then on the bottom driver side of radiator unscrew plug and drain, then turn on water hose flush till clear, then add your coolant

I am assuming your vehicle has the pink antifreeze called Dexcool. This is the recommended coolant for all late model GM cars and trucks. This coolant tends to form a pasty sludge in the cooling system which can lead to overheating and/or plugged up heater core. Try flushing the cooling system with a good aftermarket product such as prestone radiator flush. First thing to do is drain all the pink coolant, then add the radiator flush and fill with plain water. Run the engine according to directions on the flush container. Drain the radiator again and refill with plain water. Run the engine for a few minutes and drain again. Keep repeating this until all the pink antifreeze has been eliminated. Fill the system with 2 gallons of green antifreeze. Make sure the antifreeze container says it is compatible with aluminum engine parts. Hope this helps. If it does, then you won't have to replace the heater core.

Check the radiator hoses after engine is warm.
If one is cold - the thermostat has failed and must be replaced.


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What you can do is go to a parts store like Auto Zone or most part stores and have them check the codes.This will help find what could be causing the light to come on.It could just be something that was disconnected or removed when the thermostat was replaced.Let me know what you find and I`ll be glad to help you out.Good luck.

I think you started out looking in the right places. Replacing the coolant, thermostat, relay and sensor are all fairly inexpensive.

I believe you either have blockage in the system (especially if you're using tapwater), or your water pump may be failing.

I would first either take it to a radiator shop and have them flush the cooling system out thoroughly, or else pick up a chemical flush kit and do it yourself. This involves more than just drain and refill.

If this doesn't work, your next step will probably be replacing the water pump. At almost 200k miles, it's probably about due anyway.

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