What is the recommended mileage to replace a timing chain on 1999 Buick Century?

There's no recommended mileage interval for replacing a timing chain on a 1999 Buick Century (or most vehicles with timing chains, for that matter). Unlike timing belts which are made of rubber and have a predictable lifespan, timing chains are metal and are designed to last the lifetime of the engine.

However, this doesn't mean they're maintenance-free. Chains can stretch, wear, or have components fail over time, especially with age and high mileage. Instead of a mileage-based replacement, focus on these:

* Listening for unusual noises: A rattling or clicking sound from the engine, particularly at startup, could indicate chain problems.

* Checking for error codes: A check engine light accompanied by codes related to timing or camshaft position sensor could suggest issues.

* Regular maintenance: Keep up with regular oil changes. Dirty oil contributes to increased wear on the chain and its guides.

If you notice any of these issues, it's time to have a mechanic inspect the timing chain. They can assess its condition and determine if replacement is necessary. Simply relying on mileage won't be sufficient to predict when a replacement is needed.