"low coolant" light on

You should have a vacuum puller, but alternatively, you can purge it by letting in freon on the low side and opening the high side for about 4 seconds, that should purge all the air in the system.

If you are talking about the low coolant warning light, be sure and check the radiator along with the overflow tank.
If the cooling system is full, the sensor has failed.

if the raid and the reservoir are both filled you might just have a bad level sensor put a jump across the connector and see if the light goes out

are you mixing the coolant with water if yes,you need to just put straight up anti freeze ,because water evaporates at high temperatures .. also keep resorvoir full at all times there is a sensor in the tank that when is low it makes the check coolant light come on ,,....good luck

It could be low on coolant,or air in the cooling system,or the coolant low sensor needs cleaning.

If your coolant light turn on sometimes, and you can check that your coolant level is low, definitly you have a leak.

I suggest check this artricle about how to detecting coolant leak

Hope this help (remember rated and comment this).

if rad full then its the sensor in the header tank

Inside the coolant reserve tank there is a sensor for coolant level.


Over time,this sensor can get stick.


Inspect the coolant reserve tank for crack or leak.

Locate the coolant level switch/sensor and soak it in clean warm water.

Make sure it's free to move up and down the float path.

Top off the coolant tank with coolant only.

YES. But dont overfill it. Slowly add coolant to the low full line and let it run a while, like 10 minutes. if the level goes down fill it to the full line. After it cools for 30 minutes recheck the level and add as needed.

It sounds to me like you're low on coolant. When you checked the coolant level, did you actually open the radiator cap and make sure the radiator is full? The plastic tank you generally add coolant too is actually an 'overflow' or 'reserve' tank. There is a hose that runs from that tank to the top of the radiator so if the radiator gets low on coolant, more coolant -should- run in from the overflow tank. However in practice this does not always work. I have a Jeep that leaks coolant and experiences this exact same problem. Coolant will not run from the reserve tank into the radiator because the hose is plugged up, and whenever the radiator gets low on coolant the temp gauge will go real high and then drop, and the heater doesn't work well. This is because the cooling system of your car is supposed to be a closed system, full of coolant and no air. When coolant leaks out, the space it used to occupy is now occupied by air, which does not transfer heat well. When 'air' is passing through your cooling system, no heat can be transferred from your engine to the heater and radiator, resulting in a hot engine and no heat at the heater. Then when a pocket of water passes through the system, the temperature gauge quickly falls as the water absorbs the heat from the engine. The hot water that cools the engine is where the heater gets it's heat from as well, so when water passes through the heater core, the heater works, but when it's filled with air, it doesn't.