[bimmerboi318]

I'm not sure which years had plastic impellar water pumps...but i didnt think the housing would be plastic (although I could be wrong). You sure you're looking at the water pump? If I were you, I'd pull the water pump out, pull the head off, check for warpage and cracks, replace the head gasket, replace water pump if needed...hell, replace it anyways, and change the oil a couple times. The bottom end of the engine SHOULD be ok. The big problem is the head since it's aluminum and may crack easily. Besides the water pump failing, another cause for overheating could have been a blown heater hose, or just plain low coolant. Oh yeah, replace the heater hoses while doing the head gasket too, since the intake manifold has to be off anyways to get to the hoses. Was it leaking coolant when you bought the car?