I have been having problems with my 91 Trans am(5.0 TBI). First, I thought it was the thermostat that wasnt working because my car would over heat, so i installed a brand new one when i bought the car. yesterday I unscrewed the thermostat and water was up to level, It looks clogged and I wanted to get people's opinions on here on what it may be?.. Could it be the water pump that may be broken?. or something in the intake manifold? please help!! i'd appreciate it.

 

What makes it "looked clogged"?

A water pump not working will cause it to overheat, yes, but it is possible the water jackets in the intake are clogged. I know my original intake was so clogged and corroded the manifold wasn't even good for scrap metal.