Signs of Timing Chain Tensioner Failure in the 2018 Lexus LS500

1. Rattling Noise:
        A noticeable rattling sound, especially during startup, is often a primary indicator of a failing timing chain tensioner. The noise typically comes from the engine compartment and can be most intense right after starting the engine due to lack of oil pressure.

2. Engine Misfires:
        If the timing chain tensioner is malfunctioning, it can cause the timing chain to slip, leading to improper valve timing. This may result in engine misfires, which can be detected through poor engine performance or an illuminated check engine light.

3. Check Engine Light:

     A failing tensioner may trigger the check engine light. Error codes related to camshaft or crankshaft correlation often point to timing issues, which can be traced back to a problematic tensioner.

1. Poor Engine Performance:
        Reduced engine power, hesitation, and a lack of responsiveness can be symptoms of timing chain issues. The engine may struggle or stall due to improper timing caused by a faulty tensioner.

2. Metal Shavings in Oil:
        When inspecting the engine oil, finding metal shavings can be an indication of excessive wear on the timing chain or tensioner components. This can often be a sign that the tensioner is not functioning correctly, leading to increased friction and wear.

Recommended Fixes

1. Immediate Inspection:
        If you suspect tensioner failure, have your vehicle inspected by a certified mechanic as soon as possible. Early detection can prevent further damage to the engine.

2. Replacement of the Timing Chain Tensioner:
        The most common and effective solution is to replace the faulty timing chain tensioner. This typically involves substantial labor since the timing cover must be removed. Ensure that the replacement tensioner is of high quality and ideally sourced from the original equipment manufacturer (OEM).

3. Inspection and Potential Replacement of Other Components:

     During the tensioner replacement, inspect the timing chain, guides, and sprockets for any signs of wear or damage. It is often advisable to replace these components concurrently, especially if your vehicle has high mileage.

1. Regular Maintenance:
        After the replacement, adhere to a strict maintenance schedule. Regular oil changes with high-quality oil are crucial as they ensure adequate lubrication, which can prolong the life of the new tensioner and other related components.

2. Engine Diagnostics:
        Post-repair, running a full diagnostic scan will ensure all components are functioning correctly and there are no further issues relating to engine timing or performance.