I'm fooling with my neighbor's 1988 Ram 50 with the 2.0 liter Mitsu engine. Upon removing the timing belt cover, ball bearings fell over the floor. There are 2 belts under there. The main timing belt and pulleys are ok. There is a smaller toothed belt between the crank and what I assume is the oil pump. The idler pulley between them is what is toast.
Now, if this second belt runs the oil pump like I think, why is there a timing mark on the sprocket? This is what's leading me to think it might not be the oil pump. If not, what is it, and how critical is the mark? Is there probable damage if the the motor was running (it was) with a completely disintegrated idler pulley?
Thanks a bunch, all.