To remove the primary timing chain and crankshaft sprocket, it is unnecessary to detach the camshaft sprockets, their bolts, the secondary timing chains, or the primary timing chain tensioner pivot arm/chain guide; simply pivot the tensioner arm/chain guide to the left to facilitate the removal of the oil pump housing. Next, take off the steel lower oil pan and the oil pump pick-up tube and screen. Remove the oil pump-to-engine block bolts from the front of the engine, detach the oil pick-up tube from the oil pump, and then take out the oil pump housing retaining bolts. Gently pry the oil pump housing outward to clear the dowel pins on the engine block and remove it. For inspection, use a large Phillips screwdriver to take off the screws holding the front cover on the oil pump housing, clean all components with solvent, and inspect for wear and damage. Remove the oil pressure regulator cap, washer, spring(s), and valve, checking the sliding surface of the valve and the valve spring; if either is damaged, replace them as a set. Measure the clearance of various oil pump components with a feeler gauge and calipers, comparing the measurements to the specified clearances. If any clearance is excessive, replace the entire oil pump assembly, pack it with petroleum jelly to prime it, assemble the oil pump, and securely tighten the screws. Install the oil pressure regulator valve, spring, and washer, tightening the valve cap. For installation, use new gaskets on all disassembled parts and reverse the removal procedure, aligning the flats on the crankshaft with those on the oil pump gear, and tighten all fasteners to the specified torque, ensuring to replace the O-rings on the oil pump housing and engine block before installing the oil pan.
Posted by NissanPartsDeal Specialist 
