That is a freeze plug and it is there to pop out when the engine freezes so that the engine block does not crack.
I KNOW FOR THE 1990 IT IS TOWARD THE BOTTOM OF THE ENGINE BELOW THE ALT.
on bottom of engine toward the passenger side
Bottom of engine, toward the front, right side of car.
On drivers side of radiator toward engine about 3 inches from bottom.
Look carefully at the teeth. You will see that they slope up to a sharp cutting edge. The chain always moves toward the engin on the bottom of the bar and away from the engine on the top of the bar. So the cutting edge should face away from the engine on the top and toward the engine on the bottom.
Remove 2 bolts in front on the bottom of the engine cover. Remove 2 Phillips bolts in the ash tray area. and lastly there are two latches toward the back of the cover....one on each side. You then pull the bottom of the engine cover toward the rear and tilt the top out slowly. It's easy.
engine side of radiator, toward the bottom, drivers side.
the same place that it is on most engines, bottom of the engine, toward the rear, bottom of the oil pan.
Its located on the drivers side engine panel toward the bottom its very difficult to get to.
It is on the bottom of the engine toward the front end of the car. If you crawl under the front of the car it is pretty easy to find.
Yes, located toward the bottom ot the engine at the end of the crankshaft. Mazda used an integrated harmonic balancer/belt pulley.
Toward engine... the direction gas flows.