If you are absolutely sure there are no external leaks then you probably have a weak head gasket and the coolant is being pulled into the cylinders and burned with the fuel.
Found after removing and replacing the sensor and bottle still had error finally drained radiator and added correct coolant mixture in radiator, indicator went away. Appear I had a weak mixture of coolant and water in radiator, which kept giving me the "ENGINE COOLANT LOW' I guess it really was low in coolant
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The heat is not working because you are very low on coolant, probably because of the leak. Seems to me that it should leak worse when it is running, so I am going to assume you are talking about the coolant overflowing the reservoir, in which case goes back to you being low on coolant and the engine boiling the coolant.
low coolant ,froze thermostat ,leaks in hoses ,radiator
Yes, If to much leaks out this will cause the engine to over heat, smoke and or stall hence the name engine COOLant :)
If coolant leaks onto an engine it will cause no damage unless it leaks onto the alternator or into a wire harness connector of some sort. It is best to clean up leaked coolant as much as possible. It will smell a little when the motor is started. Leaked coolant on the ground is a danger to animals and children as it has a sweet smell but is very toxic.
The coolant level is low.The coolant level is low.
You have a failed gasket, seal, or hose.
yes, especially if the leak is causing coolant to leak, you can run out of coolant. then overheat.
That means the engine is running HOT. Need to check the coolant level and check for coolant leaks.
If the front of the engine leaks coolant there is a blown head gasket. This requires immediate repair as it can lead to a blown engine if not managed appropriately.
thermostat sticking or low oil or low coolant
Low coolant would be because the coolant is low or the sensor has failed, Check engine light would be because the computer has detected a problem and set a code.
Check coolant leaks with a visual inspection. Clean the engine, then see where the coolant reappears. Look under the water pump. Check engine oil to see if coolant is leaking into the oil.