Without removing the block drain plug, can the water level in the block be lowered below the level of the water temperature sensor? (Looking to remove the senor).
Yeah, I don't like disturbing those drain plugs either, it always feels like I am tempting a leak or stripped threads. I just open the drain on the radiator and let it all pour out like was mentioned above. I would just add that using a jack to raise the rear will also help to empty the block.
Not sure what year car yours is and how much room you have around the sender / engine compartment but I have replaced mine in my 70 without draining the coolant at all. You have to have everything ready in front of you. As you pull the old sender plug the hole with a finger at the same time. Grab the new sender remove finger and install. You have to be quick but I did it and lost less that a quart of fluid. Beats draining the system and refilling plus the mess associated with that. Hope this helps.
