My first concern with any 2.3-16 would be the history of the maintenance of the valves. First check is with the compression of each bore and a leakdown test for the rings. The compression test number, if uneven or low, may indicate that an exhaust valve has burned and cracked. This is fairly common when the valve clearances have been neglected.

Pull off the valve cover, shine a bright light down the timing chain and sprocket galley and inspect for wear on both the sprockets and chain guides. When those plastic guides fail, the plastic bits wind up in the oil pump and can cause damage in there.