Hello jameli_noman: My name is Roger and I will help you. The radiator has a sensor in it that is supposed to since low coolant. A couple of things can cause a problem. 1. The sensor is working and coolant is low. 2. Coolant sensor is defective. 3. Coolant sensor is contaminated by oil deposits. I would look at #3. If you were low on coolant? The coolant had to of gone somewhere. Look close at the corners of the intake manifold. Where the intake meets the cylinder heads. If you see what looks like a slimy oozy build up and you should see traces of coolant in this mess. You have a intake gasket causing the problem. This leak will let minute amounts of oil into the coolant system. This will cause the sensor to be contaminated. You can disconnect the sensor. But this defeats the early warning of low coolant and engine damage. Should you have any more questions please just ask. I will reply. Please rate the answer as this way I know it was of use. Thank You for using Fix Ya. Roger