97 Blazer Overheating

I own a 1997 Blazer manufactured in Brazil. The Blazer now has about 110,000 miles on it and we are experiencing problems with overheating – especially with the air conditioner on. Investigating, we find that there is no more fluid in the radiator. Typically we are in the highway with the air on and temperature appears normal. Then suddenly the temperature rises in to the red. Sometimes, not always, the temperature will drop but then go back up again. The fill bottle is boiling and after letting the engine cool and opening the radiator – little or no fluid. Any suggestions in remedying this problem?

How often does this happen? Do you check your coolant level regularly? Have you seen where the coolant is going? How is the Blazer running any spitting or sputtering? Does the heater work? Any coolant in the oil?
Is the water circulating?

Here are a few possible problems, but we need more info:

If you see a leak in the system that's your main problem, but probably not the only one.

If it is running rough, and you don't see any coolant leaks.....check the tailpipe for water, steam, or smoke. It could be an intake or head gasket.(DEXCOOL is notorious for eating intake gaskets).

If it appears that most of the coolant is coming out of the overflow...the problem could be the radiator cap, thermostat, water pump, or a clogged radiator, even if your problem at this time isn't the rad cap you will need to change it out. The one on the yours is a faulty design and WILL cause problems. "Stant" is the prefered brand but any spring style cap will be better than the AC DELCO that you have now.

After we get some more info we will be better able to determine the problem and tell how to fix it.

Model Chevrolet SS10/Blazer – 1997: Motor 4.3L (note: I am not sure that the Brazil models correspond exactly with the States in terms of year of manufacture)

We check the coolant every morning when starting the car. There is no leakage during the night when the car is stopped in the garage. There is however leakage after parking the car after driving with it – it is not loosing fluid when cold. We don’t know where the coolant is going. This can occur several times a day or once during the week. The engine runs fine except when the temperature is over the red mark and then it knocks. The heater and air conditioning work fine. We rarely use the heater. As far as I know there is no fluid in the oil. The last time I filled the radiator the water was circulating.

I will try changing the cap and flushing the system and see what happens.

similiar thing happened to my 97 blazer..

I would advise you to check your motor oil. With my truck, I pulled out the dipstick and can immediately tell there was coolant in it.

Took it to the dealer and they told me the intake manifold was leaking. $600 later it was all better.

similiar thing happened to my 97 blazer..

I would advise you to check your motor oil. With my truck, I pulled out the dipstick and can immediately tell there was coolant in it.

Took it to the dealer and they told me the intake manifold was leaking. $600 later it was all better.
Yes, Okonia is right, if I were you I would make sure there is no coolant in the oil as i said DEXCOOL is notorious for eating intake gaskets.

sounds like a bad rad cap.

Replace with a non acdelco rad cap. Don't get the GM cap.

The rad cap is there to keep the system pressurized which raises the boiling point. If the cap is leaking, the boiling point wil drop.

You are seeing the results of air in your system.

Also, have you mixed the green coolant in with the orange coolant in there?

I hope you don't keep driving it when it is hot like that or bye bye engine.