I replaced a coolant sensor recently (the one that screws into the block aft of the coolant bleed screw), because the previous one was leaking coolant.
Unfortunately, the leak persists. Questions-
1-What is the sensor for?
2- Does this sensor require a sealing ring or washer to stop the leak?
3-Will applying a high temperature-resistant sealant to the threads impair the functioning of the sensor?
4-In short, what is the best way to stop the leak?
The leak is slow, but is enough to annoy. Thanks in advance for your advice.