We don't have any information for freeze plug locations. Generally they are located around the engine block along center line.
Which engine do you have? Is it timing chain or belt? If belt, the leak behind the cover should be from the water pump. If there is any freeze plug behind the chain cover for chain driven engines, the coolant would get to the engine oil.
November, 22, 2012 AT 6:22 PM
The engine is a 3.0L. Front wheel drive '96 Nissan Quest XE. When I add water it "flows" out from above the water pump and behind the timing chain cover. I have changed the thermostat housing/gasket. The water pump is not leaking from the weep hole. I plan to remove the a/c compressor and the top half of the timing belt cover to get a better vantage point as to what is leaking. The rapid flow of leaking water gave me the missing/damaged freeze plug theory.
November, 22, 2012 AT 6:47 PM
Our database indicates this is a belt driven engine. Refer to diagram.
Whatever it is since you can't see the source of the leak, you would need to remove the cover to check. The upper timing belt cover should be easy to remove.