Overheating with no coolant leak?

Yep, I would do the thermostat first which is most common when over heating in a short amount of time. Please start a new thread for the sensors and intake manifold gasket because we only handle one problem at at time. Also, make sure the cooling fans are coming on when the engine is hot. Don't start on repairs until the engine has completely cooled off and is cold, then start by draining the coolant and disconnecting the 12 volt battery. Here is what the thermostat assembly looks like. Please upload a short video in your response of the problem, so I can see what's going on :) Check out the images (below).