Oil Pump: Inspection
WARNING: This page is about a different car, the 2001 Ford ZX2 and 2000 Ford ZX2. However, it is still accessible from the selected car via links, so may be relevant.
Check oil pump housing and gears for damage or excessive wear. Check gears for burrs, nicks or scoring. Small imperfections can be removed with an oil stone. If housing or gears are excessively worn, replace oil pump assembly. Inspect pressure relief valve spring for breakage or weak spring tension. Ensure pressure relief valve piston moves freely in bore. If pressure relief valve spring is worn or damaged, replace pump assembly.