While timing chains are generally more durable than belts and don't require the same regular replacement schedule, they're not maintenance-free. At 150,000 miles, a chain *might* still be okay, but it's definitely nearing the point where issues could start to arise. It's not a guaranteed replacement at that mileage, but a thorough inspection by a mechanic is highly recommended.
Signs of a failing timing chain can include:
* Unusual noises from the engine: A rattling or clicking sound, especially at startup or under load.
* Decreased engine performance: Loss of power, rough running, or hesitation.
* Check engine light: While not always indicative of a timing chain problem, it could be a related issue.
Instead of simply assuming it's fine at 150,000 miles, have a qualified mechanic inspect the chain and its tensioner. They can determine its condition and advise whether replacement is needed now or can be deferred for a while longer. The cost of a failed timing chain (potentially leading to major engine damage) far outweighs the cost of a preventative inspection and potential replacement.
