OEM 2004 Scion xB Cylinder Head Gasket

2004 Scion xB Parts Questions & Experts Answers

• Q: How to replace the cylinder head gasket on 2004 Scion xB?

  A: The replacement procedure for cylinder head gasket begins with fuel pressure discharge followed by chain sub-assembly removal and front exhaust pipe separation through the removal of two bolts and two compression springs. The replacement process starts with removing No.1 exhaust manifold heat insulator through 4 bolts before moving onto the manifold support bracket by detaching its 3 bolts. Start by removing the air cleaner assembly followed by accelerator control cable assembly separation and finally remove the throttle body assembly. Beginning with engine wire disconnection the technician follows by removing the water filler sub-assembly after detaching the radiator inlet hose as well as radiator hose No.3 and radiator reservoir tank hose together with the removal of 2 bolts. To remove the intake manifold maintain the recommended sequence for unbolting 3 bolts and 2 nuts while simultaneously removing the gasket substance. Pull out the oil level gauge guide after removing both the gauge along with its bolt. The first task removes the union to check valve hose between the brake booster and the radiator hose inlet from the union connection. The fuel tube sub-assembly needs Special Service Tool: 09268-21010 to disconnect it while letting go of the heater water inlet hose A that is attached to water bypass pipe No. 2. The open-ended bolt on water by-pass pipe No.1 needs to be unscrewed to separate the pipe. Users must rotate the crankshaft 40 degrees counterclockwise from TDC and align the oil jet hole with the timing mark to protect piston valves before the process of loosening and removing 19 bearing cap bolts and 9 bearing caps and the No. 1 and No. 2 camshafts when keeping the camshaft at a level position. The cylinder head sub-assembly requires uniform loosening of 10 bolts using an 8 mm bi-hexagon wrench in specified sequence before the removal of the cylinder head gasket avoiding washer separation into the cylinder head. Measure the set bolt length on the cylinder head with vernier calipers to check standard limits of 142.8 to 144.2 mm and maximum limit of 147.1 mm. Replace any set bolts that exceed the maximum limit. Position a new cylinder block gasket with the Lot No. stamp oriented upwards and oil-free surface on the cylinder block before carefully placing the cylinder head on the gasket. To install the cylinder head sub-assembly use a continuous bead of seal packing with 3.5 to 4.5 mm diameter while cleaning the contact surface from oil before oil pan installation within 3 minutes. Use a light coating of engine oil on the cylinder head bolt threads before installing the 10 bolts with plate washers along with a uniform 8 mm bi-hexagon wrench application up to 29 Nm torque, then apply paint marks on bolt fronts with subsequent bolt tightening by another 90 degrees to achieve 180-degree opposite front bolt positions. The camshaft needs engine oil applied to its journals before positioning it on the cylinder head with the timing mark above while tightening the bolts initially to 13 Nm followed by bearing cap No. 1 installation with a torque of 23 Nm. Water by-pass pipe No.1 receives a bolt torqued to 9.0 Nm and the installation includes connecting the fuel tube sub-assembly and adding the oil level gauge guide with new O-ring and bolt torqued to 9.0 Nm. Place a new gasket on the intake manifold then secure and tighten the manifold joints between the 3 bolts and 2 nuts with force of 30 Nm. The procedure involves installing both water filler sub-assembly bolts to 7.5 Nm torque specifications alongside reattaching radiator hoses and mounting throttle body assembly framework and air cleaner assembly with manifold support bracket using 3 bolts torquing at 37 Nm. Use 4 bolts with 8.0 Nm torque to mount the heat insulator on the exhaust manifold No.1 before installing the exhaust pipe front assembly with new gasket material. The two compression springs should be added alongside two bolts which must be torqued to 43 Nm. The last step includes the installation of the chain sub-assembly followed by engine oil addition and leak inspections for both oil and coolant systems and fuel.