Did I cause the problem???

I replaced the starter on my Northstar engine (94) and now the car overheats. I was wondering if an improper seal of the intake (that I proped up to remove the starter) would cause this problem.

Any help would be greatly appreciated.

Probably not. A plenum leak would cause a poor idle and driveability problems but unlikely to cause an overheat situation. How is the tension on the water pump belt? Is the tensioner operating freely?

Probably not. A plenum leak would cause a poor idle and driveability problems but unlikely to cause an overheat situation. How is the tension on the water pump belt? Is the tensioner operating freely?

Thanks for the reply. I noticed water going into the reservour. I was told that this is caused by pressure buildup from a leaking head gasket. I didn't, however, notice any oil in the water. Is there anything else that would cause this problem, or is it the head gasket?

It could be the head gasket, of course, but look at less drastic situations first. Is the belt turning the water pump? Are the cooling fans coming on when the AC is on or after idling for a while and the coolant temp hits 240? Bad radiator cap?
Head gaskets are a huge job on a N* engine. Due to the design, you won't find water in the oil if an N* headgasket lets go.