OEM 2003 Toyota Highlander Cylinder Head Gasket

2003 Toyota Highlander Parts Questions & Experts Answers

• Q: How to replace the Cylinder Head Gasket on 2003 Toyota Highlander?

  A: The first step to replace the Cylinder Head Gasket for the 2AZ-FE engine (2003 MY) requires preventing gasoline leakage followed by upper center front suspension brace sub-assembly removal and chain sub-assembly removal. The 4WD drive type requires coolant draining and oil transferring before installing a new gasket and drain plug which must be torqued to 49 Nm (500 kgf-cm, 36 ft. lbs.). The replacement process starts with disconnecting the radiator hose outlet then the union to check valve hose and heater inlet water hose before separating the fuel tube sub-assembly. Disassemble the camshaft timing oil control valve assembly and front drive shaft assembly RH (using Special Service Tool: 09520-01010, 09520-24010, 09520-32040) and engine mounting insulator assembly RR and transverse engine mounting bracket (4WD drive type) by taking out their respective bolts. The service starts by taking out the intake manifold while disconnecting both water by-pass hoses and continuing with the removal of exhaust manifold heat insulator No.1 and exhaust manifold converter sub-assembly followed by No.2 and finally No.1 camshafts. Use a 10 mm bi-hexagon wrench to evenly loosen the 10 cylinder head bolts which will result in the removal of the assembly while maintaining the cylinder head washers intact. Vernier calipers determine cylinder head set bolt length while replacing any bolts exceeding 164.2 mm (6.465 inch) maximum length. Before installation, a new cylinder head gasket should be placed with the Lot No. stamp facing upward and both surfaces must be clean of oil before laying the cylinder head carefully to prevent gasket damage. The technician must install the cylinder head within three minutes while tightly fastening the bolts two times using pliers for 79 Nm torques. Afterwards, mark the marked bolts before retightening them to 90 degrees torque level. Small tasks follow to complete the job including installation of the exhaust manifold converter sub-assembly with a new gasket (37 Nm (378 kgf-cm, 27 ft. lbs.) torque) then use of the exhaust manifold heat insulator No.1 followed by the intake manifold (torque specified). Afterward the front drive shaft assembly RH and camshaft timing oil control valve assembly are installed. Reinstall the transverse engine mounting bracket alongside the engine mounting insulator assembly RR, then put on the front drive shaft assembly RH and camshaft timing oil control valve assembly. Proceed with connecting the fuel tube sub-assembly then install the chain sub-assembly (using Special Service Tool: 09309-37010) along with the crankshaft position sensor and front suspension brace sub-assembly upper center that requires an 80 Nm (816 kgf-cm, 59 ft. lbs.) torque. Before finalizing the engine oil version, you must add coolant and transfer oil (specific for 4WD drive type) into the system. Ensure that the filler plug achieves 49 Nm torque (500 kgf-cm, 36 ft. lbs.) then inspect for leaks in all fluid lines and verify idle speed, ignition timing, CO/HC readings, ABS speed sensor signal, and perform front wheel alignment adjustments.