How to Prevent Failure of the Timing Chain Tensioner

The timing chain tensioner is a component in the automotive engine that keeps the chain under the proper amount of pressure. If the tensioner isn't doing its job, the chain could snap, causing the valves to contact the pistons when they are supposed to be closed and leading to major engine damage.

The Tensioner works by using hydraulic pressure to maintain an appropriate tension on the chain. The tensioner is attached to the camshaft sprocket and the crankshaft sprocket through the oil pump, and uses a piston to force the chain guide inward against the chain. It also has a ratchet cylinder that moves the plunger and tensioner to keep the chain in place. The tensioner also has a camshaft bolt access hole plug that's installed through the front of the engine.

A failure of the tensioner can lead to the chain slapping against the camshaft sprockets or the sprocket gear. This causes the chain to become loose and can cause it to slip or jump, which will affect other areas of the engine as well.

Other symptoms of a failing tensioner include an engine that isn't running properly, such as having trouble starting or misfiring. This is a sign that the tensioner is not able to create the correct tension on the chain and needs to be replaced.

Changing the vehicle's oil at the recommended intervals will help to extend the life of the tensioner and other parts of the engine. This includes using the type of oil recommended in the owner's manual. It is also important to make sure the chain assembly is lubricated with proper oil to prevent mechanical failures.

Another way to help prolong the life of the tensioner is to have it cryogenically treated. This process cools the steel with liquid nitrogen, which hardens it and helps to increase its lifespan. It is important to have this done professionally, however.

The Tensioner should be reset after installing the new parts, and this is easily accomplished by removing its snap ring, turning its ratchet cylinder into the piston assembly to'reload' it, and then reinserting the retaining clip and tightening it. It is a good idea to have some blue loctite on hand while doing this to ensure the assembly stays secure during this step.

Before reinstalling the Tensioner, it is also a good idea to apply some sealant around the threaded hole in order to prevent a future leak of oil from that area. Once the Tensioner is reinstalled, it should be torqued to 75 Nm (55 lb in). IMPORTANT: Make sure the tensioner's guide bolt access hole plug is sealed by first installing a new seal, and then screwing the threaded plug back into place and sealing it with more loctite.