because your coolant level is too low. put some antifreeze in it......
On a 1999 Chevy Venture, the low coolant sensor is typically located in the coolant reservoir tank. It is usually found near the bottom of the tank, where it detects the coolant level. To access it, you may need to remove the tank from the vehicle for easier inspection or replacement. Always consult the vehicle's service manual for detailed instructions specific to your model.
Check coolant level Cooling fan working? Dirt or clogged radiator? Defective radiator cap?
Check coolant level I'm pretty sure it's the head gasket, maybe before it was over heater.
bad coolant level sensor in either side or bottom of plasit coolant resivoir,
If you are checking the coolant level at the overflow bottle, it may look normal (between the low & high marks). But the coolant level sensor is mounted on the passenger side of the radiator, down several inches from the top. In other words, you need to check the coolant level AT the radiator cap, but only when the engine is COLD. If it is OK at that point and the overflow bottle, then the coolant level sensor most likely needs to be replaced.
if coolant is ok!! then check coolant sensor.
If coolant level is correct - could be a defective sensor
Check your coolant level...
unfortunately the Chevy venture is known for have many of the sensors going bad. I have a 2000 Chevy Venture that gives the wrong readings for everything. I never know where my gas level is until it is actually 'empty'.
To remove the radiator drain plug on a 1998 Chevy Venture, first ensure the engine is cool and the vehicle is on a level surface. Locate the drain plug at the bottom of the radiator, then use a socket wrench or pliers to carefully unscrew it counterclockwise. Be prepared for coolant to drain out, so have a container ready to catch the fluid. Once the coolant has fully drained, you can replace the plug and tighten it securely.
Check your coolant level.
Perhaps low coolant level This is true, but why???? It's the first sign of a bad intake manifold gasket. Coolant leaking into the oil chambers of your van and into the oil. If this doesn't get fix for about $700, the oil will break down because of the coolant and then the internal parts of your engine will break. New Engine!!!