Lexus 11101-29485 Cylinder Head Sub-Assembly

For vehicles with 1999 through 2007 models, start by lowering the fuel system pressure and cutting the negative battery cable. Empty out the coolant in the engine, then take off the drivebelt and alternator. Start by removing the valve cover, throttle body, fuel injectors, and fuel rail. Then take away the intake manifold and exhaust manifold. Support your engine's bottom with a jack on the floor and pieces of wood after taking off from the pressed oil pan part. Then remove the timing chain and camshaft sprockets. Follow the steps: disconnect the valve timing control valve, take note, unhook the cooling hoses and wiring from the cylinder head, work to unscrew the cylinder head bolts by hand in 1/4-turn additions in reverse order of how you tightened them. Take the cylinder head off the engine block, using a little extra force when needed, then pull out any leftover components to clean and check. Before putting the pieces together, clean the connection area using a gasket scraper and brake cleaner spray applied to both the base of the engine block and top of the cylinder head. Push flat shop towels inside the cylinders to block debris. Clean up loose materials with a canister vacuum tool. Look for damage on the block and cylinder head connection points, fixing anything found. Push a new tap into the holes in the cylinder head bolts, clean them with compressed air, and remove any dings. Place the taken-out parts back in place, lay the gasket over the block dowels, and put silicone adhesive on both ends of the gasket. Turn on your engine oil, set the cylinder head carefully on top of the block, then slide new bolts through until they're finger-tight, following the correct order. Set the parts back in place, starting with the last part you took out. Leave the engine off for at least four hours before oiling it, including coolant. To finish, look at and fix valve settings when needed, empty used oil from both the engine and filter, add transmission fluid to 4WD vehicles, pump fresh coolant in, and turn on the engine to see if any fluid is leaking out.

New cylinder head bolts should be used when installing the cylinder head. This procedure applies to either cylinder head, and the manufacturer recommends removing the engine and transaxle assembly to perform it. Begin by removing the camshafts and camshaft housings, followed by the exhaust manifolds. If removing the left cylinder head, gradually loosen and remove the two front bolts. Remove the cylinder head bolts gradually and evenly, in the order opposite that of the tightening sequence, then take off the cylinder head from the engine block. Discard the old cylinder head gasket. Ensure the mating surfaces of the cylinder heads and block are perfectly clean before installation. Use a gasket scraper to eliminate all traces of carbon and old gasket material, then clean the surfaces with brake system cleaner. Stuff the cylinders with clean shop rags to keep out debris while working on the block, and use a vacuum cleaner to remove any material that falls into the cylinders. Check the block and head mating surfaces for nicks, deep scratches, and other damage; slight damage can be removed with a file, while excessive damage may require machining. Use a tap of the correct size to chase the threads in the cylinder head bolt holes, then clean them with compressed air to ensure nothing remains in the holes. Position the cylinder head gasket on the engine block with the lot number stamp facing up, then carefully place the cylinder head on the gasket. Apply a light coat of oil to the new cylinder head bolts, install and tighten them gradually and evenly, in the proper sequence, to the initial torque. After tightening all eight bolts to the initial torque, mark the front edge of each bolt, then retighten each bolt in the same sequence another 90 degrees, repeating this process one more time for a total of 180 degrees from the initial torque. If installing the left cylinder head, install the two front head bolts and tighten them in the correct sequence to the torque. If both cylinder heads were removed, install the other cylinder head now. Proceed to install the intake and exhaust camshafts, followed by the camshaft timing oil control valve, oil control valve filter, and VVT-i sensor. Install the timing chains, timing chain cover, and all components attached to the cover. The remainder of the installation is the reverse of removal. Finally, install the engine/transaxle assembly, refill the engine with oil and coolant, reconnect the cable to the negative battery terminal, start the engine, and check for leaks.

To remove the cylinder head, first relieve the fuel system pressure and disconnect the cable from the negative terminal of the battery, then drain the engine coolant. Next, remove the drivebelt and alternator, followed by the valve cover, throttle body, fuel injectors, fuel rail, intake manifold, and exhaust manifold. Remove the timing chain and camshaft sprockets, ensuring the engine is supported from below with a floor jack and a block of wood after the pressed steel portion of the oil pan is removed. For 2008 and later models, remove the camshafts, lifters, and camshaft housing. Label and disconnect the coolant hoses and electrical connections from the cylinder head, loosening the cylinder head bolts in 1/4-turn increments until they can be removed by hand, following the reverse order of the tightening sequence. Lift the cylinder head off the engine block, prying carefully if it is stuck, and remove any remaining external components for thorough cleaning and inspection. For installation, ensure the mating surfaces of the cylinder head and block are perfectly clean, using a gasket scraper and brake system cleaner to remove all traces of carbon and old gasket material. Stuff the cylinders with clean shop rags to keep out debris and use a vacuum cleaner to remove any material that falls into the cylinders. Check the mating surfaces for damage, chasing the threads in the cylinder head bolt holes with a tap and cleaning them with compressed air. Install the components that were removed, position the new gasket over the dowel pins in the block, and apply RTV sealant to the ends of the cylinder head gasket. Carefully set the cylinder head on the block without disturbing the gasket, apply clean engine oil to the threads and under the bolt heads of the new cylinder head bolts, and tighten them finger tight before following the recommended sequence for final tightening. The remainder of the installation follows the reverse order of removal, with a caution to wait at least four hours before adding oil and coolant and starting the engine. For 1999 through 2007 models, check and adjust the valves as necessary, change the engine oil and filter, refill the transfer case for 4WD models, and refill the cooling system, running the engine to check for leaks.

Remove the alternator and unbolt and set aside the power steering pump.