I own a '98 2.2Lt. Isusu Amigo. I think my water pump is out. The Coolant, Drive belt, engine oil, and fan blade seem to be ok and I already replaced the thermostat but engine still overheats and water boils. I believe the water pump is the one on the top right pully as you face the engine from the front of the vehicle. I have replaced water pumps many years ago. How hard would it be for me to do this job myself and how can I confirm this is the problem?
The water pump on this engine is about center-left as you look at the front of it. It is under the timing cover and requires removal of the cover and timing belt. Timing can be tricky to get right on these engines so use caution. Isuzu's are good for head gaskets also. While the engine is running cold, have the radiator cap off, watch for water movement indicating the water pump working. If the coolant is being pushed out of the radiator, chances are you have a bad head gasket.