Hi there I'm just trying to pinpoint where and what is actually causing the leak... So here's the diagnosis so far

Temp guage has been running high so I decided to swap
Out the thermostat, still high. After I chose to swap out temp sensor.. Still running high. I check my recently filled coolant and notice it's empty. I buy another 4litres And add it to the rad directly... I start my blazer (of which there has been no issues) and take a look into my engine and manifold from above to see if the water pump is spewing or the Intake manifold itself. Nothing noticeable... Next I climb underneath and notice what appear to be a leak. I shut the truck off to see if the change in pressure will cease the leak. And it does. So I start her u again and watch and it's leak quite rapidly from what appears to be a bolt that's holding in the crankshaft censor... Now I'm no mechanic clearly why im here in the forum. I believe it's the crankshaft censor that is located underneath about dead centre on the engine. Behind the crank pulley? Anyways if anyone can help that would be awesome I will try and post a pic of what the area I'm talking about is.. And basically I need to know my next course of action... Is this a deal issue? Intake manifold gasket issue? Water pump dead? I'm stumped!