Lexus 16100-29085 Engine Water Pump Assembly

A failure in the water pump can lead to engine damage due to overheating. To check if the water pump is working properly, squeeze the upper radiator hose while the engine is running and warmed to normal operating temperature. A pressure surge should be felt as the hose is released. Water pumps have weep or vent holes, and if there is a failure in the pump seal, coolant will leak from this hole. To find the hole in the water pump, use a flashlight to look through the space behind the pulley just below the water pump shaft. A slight gray discoloration around the weep hole is normal, while dark brown stains indicate a problem. If the water pump shaft bearings fail, there may be a howling sound at the front of the engine while it is running. Bearing wear can be felt if the water pump pulley is rocked up and down. However, do not mistake drive belt slippage, which causes a squealing sound, for water pump failure. Spray automotive drive belt dressing on the belts to eliminate the belt as a possible cause of the noise.

To remove the water pump on 4-cylinder models, first disconnect the negative battery cable and drain the cooling system. Then, remove the timing belt and idler pulleys, alternator adjusting bar, and lower radiator hose. Remove the bolts from the water pump, noting their locations, and remove the pump and gasket. Thoroughly clean all sealing surfaces. To install, use new O-rings and gaskets, and tighten the bolts to torque specifications. Refill the cooling system and check for leaks. For V6 models, follow similar steps, but also remove the timing belt and camshaft sprockets, water inlet pipe and thermostat, and number 3 timing belt cover. Thoroughly clean all sealing surfaces and use a metal and rubber gasket for installation. Refill the cooling system and check for leaks.

Lexus needs you to disconnect the battery negative terminal and drain the cooling system for all its models except 2013 and 2014. For all 2.4L models, remove (from right to left) the right inner fender splash shield, control rod of engine movement, bracket, engine stay, drivebelt, and alternator. Take off the water pump pulley, disconnect power cables, unscrew fasteners from where pump attaches, then use a wood block to pry the water pump out of its spot. Wash, seal, and slide back everything in the correct order, using right torque to attach it all. Add more coolant, start the engine, and look for any sign of trouble. First for 2.7L engines, take off all engine covers, radiator trim, fender splash shield, drive belts, alternator, and pulley tools. After that detach and clean the water pump before rebuilding it. To fix the water pump for cars with 3.0L and 3.3L engines, take out the timing belt, camshaft sprockets, and number 2 idler pulley, remove the water pump while carefully cleaning all bonding spot surfaces and use a new metal/rubber seal. For 3.5L vehicles, first lift the engine on a jack stand. Then, remove all the needed engine mounts and other parts to get access to the water pump. Make sure to deep clean all the sealing surfaces before putting on new gaskets when reinstalling. After running the car, top up the cooling system and inspect for leaks.

A failure in the water pump can cause serious engine damage due to overheating.

1. Remove the engine covers, radiator support trim cover, and the inner fender splash shield on the right side. 2. Remove the drivebelt. 3. Remove the engine harness ground connector. 4. Remove the upper front engine mount bracket and the engine movement control rod. 5. Remove the rear engine mounts and insulators. 6. Remove the front engine mounts and insulators. 7. Place a floor jack with a wooden block under the engine oil pan for support and remove the front engine mounting bracket. 8. Remove both the front and rear drivebelt idler pulley assemblies. 9. Remove the bolt and the drivebelt tensioner pulley. 10. Hold the water pump pulley with a special pin-spanner wrench and remove the pulley mounting bolts. 11. Remove the coolant inlet or thermostat housing and gasket. 12. Remove the water pump mounting bolts, then remove the water pump/pulley and gasket. 13. Thoroughly clean all sealing surfaces, removing all traces of old gasket and sealer. 14. Install a new gasket to the water pump and tighten the bolts and nuts to the torque. 15. Install a new gasket and O-ring to the water inlet housing. 16. The remainder of installation is the reverse of removal. Tighten the bolts to the torque. 17. Refill the cooling system and run the engine, checking for leaks and proper operation.

INCLUDES GASKET