Overheating Problems '98 2.4 liter

My Cavalier has been having overheating problems for a while. It went through a whole thing of antifreeze in less then 24 hours. Rediculous! I'll be driving and if I go over 40-45 mph, the temperature gage will get up to the line next to the red. Not all the way into the red, but close enough to it. And you can hear the coolant boiling out of the surge tank. I've replaced the thermostat and it's still doing it. Any suggestions? I'de rather not take it to a shop and get ripped off.

I have a '00 Sunfire 2.2L. I started having some of the same problems recently that many others were having. The engine would start overheating and boiling the coolant out of the system. I drained and flushed the radiator and block then refilled with new coolant. It still overheated.

So I replaced the thermostat. It did ok while I was driving fast, but when I was moving slow, it would start getting hot again. The fan worked fine; it came on at 222F like it is supposed to. I was getting heat with the heater on high.

I finally realized, that the with the temperatures that the gauge was showing me, the heat coming from the heater was not that hot. So after researching some on the internet, I partially drained the system and disconnected the hoses that connect the heater core to the rest of the system. On the 2.2L, one hose connects to the thermostat housing and the other on the other side of the engine.

Now that the heater core is separated from the system, I used a garden hose nozzle to apply higher water pressure to the heater core to back-flush it through the hose that was disconnected at the thermostat housing. This pushed a large clog out of the heater core. Then reconnected everything and filled with coolant. Then let the engine idle with the coolant filler cap off, so any air can get out of the system. Topped off the reservoir and bleed the system at the bleeder screw.

Now everything works fine. Hope this helps you or someone else.

When I replaced my heater core lines, I routed one wrong and it kinked. Same problem, except I didn`t lose any coolant - only when I opened the tank to relieve the pressure!

Check your heater core and heater core lines..... as soon as I straightened the kink in the line out, my temp gauge returned to normal, and it`s been fine ever since.

I just bought my 98 cavi 2 months ago and it did great for the first 3 weeks then started having problems, recently it has been running hot and over heating. i checked the anti freeze reserve tank about a month after gettin all the fluids filled and an oil change at valvoline. The tank was completely dry. I put a gallon in and it was fine for bout 2 weeks then it almost over heated again. put more fluid in again. I noticed it seemes to leak for like a day after after i put fluid in then it stops leaking but burns fluid really fast, was told it prolly has a crack in hoses so we put some radiator stop leak in it 3 days later i was in the store for 5 mins to come out and my boyfriend said it had started smoking and then blowing fluid from the top of resever tank (with the cap on). It had to have dumpped all the fluid. there was a puddle in the parking lot that was bigger than my car. we let it cool down for 4 hours came back with more fluid then i drove it home. it is still burning fluid like crazy (i put in 1/2 a gallon every 3 or 4 times i drive it).....help please? i know NOTHING about cars....