1kingslimg

I have a 1993 Lexus sc300 and I've run into a problem, Early January my car started overheating, so first thing i do is go to change the thermostat. When i begin to do so i notice that there wasn't one in it, so i figure the previous owner took it out. So i continue and put one in because there wasn't one. Its been driving fine until yesterday. Its sat for like two or three day before i drove it again. i got to my destination an notice i noise after i cut the car off. it was the water boiling over into the overflow tank. I did i radiator flush today and it did it while i did the flush. Can someone give me any other ideas of what it could be.

LoveSCs

iTrader: (2)

How old is your water pump? Is your radiator in good shape? Any debris on the front of it blocking airflow? What kind of fan are you running, stock or electric, and is it in good working order? Is your serpentine belt in good shape?

eknine9

iTrader: (8)

If it's boiling coolant but temp gauge is normal replace the radiator cap. When they go bad they no longer maintain proper pressurization and the coolant boils at lower temperatures. That'd be something to consider replacing, and it's super cheap and quick so definitely the first thing I'd check here.

LoveSCs

iTrader: (2)

Excellent suggestion

1kingslimg

Im not sure how old everything is i bought the car a year ago and its belt driven.

I just tried replacing the cap today. I let it run for about 10 minutes and i still got some bubbling in to the over flow tank.

lexuscfour

Check the coolant overflow bottle. It could have spider cracks in it which would make coolant burst out under pressure. This happened to me. You may need some JB Weld to fix it.

pcolex

If you've flushed the coolant system, and are confident the cap and thermostat are good, check the heater hose going to the firewall. If its not very hot and you boiling over, then coolant isn't circulating through the block, which means the water pump is out.