Inspect the relief plunger.

Coat the plunger with engine oil and check that it falls smoothly into the plunger hole by its own weight.

If necessary, replace the timing chain cover.

Inspect the rotor side clearance.

Using a feeler gauge and precision straight edge, measure the clearance between the rotors and precision straight edge.

If the side clearance is greater than maximum, replace the rotors as a set. If necessary, replace the oil pump cover or timing chain cover.