Can I Drive My Car With a Failing Timing Chain Tensioner?

Unless tensioners are working correctly, chains could jump or snap and cause severe internal engine damage. Depending on what kind of engine it is (interference or non-interference), this could result in bent valves or even damaged cylinder heads.

The chain tensioner utilizes both an internal spring and oil pressure to maintain proper timing chain tension, designed to last the lifetime of a vehicle. Some OEM systems rely solely on spring tension while others employ both spring tension and hydraulic pressure in their control of chain tension.

While running, oil pressure pushes the plunger forward until it contacts sprockets or chains. When the engine turns, the ratchet mechanism prevents the plunger from moving back out to take up the slack in the chain. Thus allowing the spring to apply constant tension until wear limits or something breaks.

While under tension, the chain pulls on its sprockets. If the misalignment between the crankshaft and sprockets leads to misalignment between chain teeth and timing belt sprockets is severe enough, then teeth may miss or shift out of sync and cause the engine to run erratically and/or the check engine light to illuminate.

Initial signs of a failing chain tensioner usually include an engine-running rattle followed by the check engine light illuminated. Old oil tends to degrade seals and block oil passageways within the tensioner; eventually, its internal spring may also lose its ability to properly tension chains.

Are My Car's Timing Chain Tensioners Working Properly? In some instances you can drive with a defective timing chain tensioner; however, only for short distances. If the chain or tensioner jumps or breaks suddenly it could put your engine out of sync and lead to severe internal engine damage; especially with interference engines where their chains could potentially cause major piston damage.

The sprockets on which the chain runs typically consist of cast or stamped metal and may develop sharp edges due to wear that causes them to rattle against each other when pulled and pushed by the chain. Plastic chain guides located on these sprockets may also wear over time and produce similar sounds when moved back and forth by pulling and pushing.

If the rattling noise is loud enough, it is advised that you locate a safe parking space and switch off your engine before taking further steps. Next, remove any belts or chains and inspect tensioners for damage before replacing them as appropriate. If this continues then calling a tow truck and taking your car to a repair shop are both options that could guide as to the appropriate course of action for your engine.