Q: How to remove, inspect, and install the oil pump in 3.0L and 3.3L V6 engine for the 2008 Toyota Highlander?
A: To remove the oil pan, timing belt, crankshaft sprocket, and crankshaft position sensor, place a jack under the engine and remove the powertrain mounts. Next, take out the oil pick-up tube, alternator with its bracket, and unbolt the air conditioning compressor without disconnecting the refrigerant lines. Remove the air conditioning compressor bracket, power steering pump adjusting bracket, and pry the pump away from the oil pump body. Detach the timing belt tensioner pulley using a 10 mm hex bit or Allen wrench, then remove the bolts to detach the oil pump from the engine, prying carefully if necessary. Remove the O-ring, oil pressure relief valve snap-ring, retainer, spring, and valve, then use a large Phillips screwdriver to take off the screws retaining the body cover to the rear of the oil pump. Lift off the cover and remove the pump rotors, scraping away any sealant and old gasket material from the pump body and engine block, and clean the mating surfaces with lacquer thinner or acetone. Clean all components with solvent and inspect for wear and damage, checking the oil pressure relief valve sliding surface and valve spring, replacing them as a set if damaged. Measure the clearance of the driven rotor-to-oil pump body, rotor side, and rotor tip with a feeler gauge, comparing to specifications. Pry out the old crankshaft seal, apply multi-purpose grease or engine oil to the new seal's outer edge, and drive it into place with a seal driver and hammer, also greasing the seal lip. Place the drive and driven rotors into the pump body with the marks facing out, pack the pump cavity with petroleum jelly, and install the cover, tightening the screws in a criss-cross pattern. Lubricate the oil pressure relief valve with engine oil and install the valve components in the pump body. Clean the gasket surfaces with acetone or lacquer thinner, apply a 2 to 3 mm wide bead of anaerobic sealant to the oil pump, and position a new O-ring on the block. Engage the flats on the oil pump drive rotor with the crankshaft and slide the pump into place, ensuring the new O-ring is installed and aligned. Install the oil pump mounting bolts and tighten them, then use a new gasket to install the oil pick-up tube and tighten the fasteners. Reinstall the remaining parts in reverse order, add oil, start the engine, check for oil leaks, and recheck the engine oil level.