How to Replace a Timing Cover Sealby Thomas West
Some automotive engines utilize a timing chain and sprockets to turn the camshaft. The timing chain is usually located at the front of the engine block and is lubricated with motor oil under pressure. For this reason, the timing chain is protected with a metal or plastic cover that is sealed to prevent oil leakage. Over time the seal (which is made of rubber or cork) will deteriorate and replacement will become necessary. The seal will also need to be replaced any time the timing cover is removed for maintenance of the timing chain.
Open the hood and disconnect the negative battery terminal by loosening the holding clamp nut with an adjustable wrench in a counterclockwise direction. Place a drain pan underneath the radiator and remove the petcock in a counterclockwise direction. Allow the coolant to drain into the drain pan and set it aside for reuse. Replace the radiator petcock.
Remove the harmonic balancer holding bolt (located on the crankshaft at the front of the engine block) in a counterclockwise direction with an adjustable wrench. Use a puller and remove the harmonic balancer by placing the puller over the balancer and screwing the two bolts into the threaded holes in the balancer. Tighten the bolts with an adjustable wrench in a clockwise direction until the balancer slides off of the crankshaft. Remove the puller from the balancer by backing out the two bolts with an adjustable wrench in a counterclockwise direction. Set the balancer aside.
Remove the engine fan and the water pump by removing the holding bolts in a counterclockwise direction with an adjustable wrench. Set the fan and water pump aside.
Remove the timing cover holding bolts in a counterclockwise direction with an adjustable wrench. Pry the timing cover off with a flat-blade screwdriver if necessary. Scrape the seal or gasket residue from the cover mating surface on the engine block and from the timing cover with a gasket scraper.
Apply a small, even bead of gasket sealer to the mating surface of the engine block. Place a new timing cover seal over the sealer, making sure the mounting holes in the block and the seal line up. Place the timing cover over the seal and screw in the holding bolts in a clockwise direction with an adjustable wrench.
Replace the water pump and engine fan and tighten in the holding bolts in a clockwise direction with an adjustable wrench. Replace the harmonic balancer over the crankshaft and tighten the holding bolt in a clockwise direction fully until the balancer seats into position.
Open the radiator cap in a counterclockwise direction and pour the coolant from the drain pan back into the radiator, using a funnel. Close the radiator cap. Reconnect the battery negative terminal by tightening the holding clamp in a clockwise direction. Start the engine and check for leaks. Tighten any connections if needed. Close the hood.
Things You'll Need
- Adjustable wrench
- Drain pan
- Harmonic balancer puller (available at auto parts stores)
- Flat blade screwdriver
- Gasket scraper
- Gasket sealer
- Timing cover seal or gasket
- Never work on a hot engine as you can be scalded by coolant or motor oil. If the vehicle has been run recently, allow it to cool for several hours before performing this procedure.