Does the 2005 Nissan Sentra have a timing belt or chain?

The 2005 Nissan Sentra comes equipped with a timing chain rather than a timing belt. The belts generally have to be replaced every so often but the chains should last for the life of the vehicle unless You get pretty unlucky. Belts have to be replaced because they sit outside of the engine and are exposed to things whereas the chain is in the engine and gets help from the engine oil. Belts should be changed every 60,000 to 100,000 miles or so and You should just inspect the chains every 150,000 miles or so. To inspect the chain You can pull off the valve cover and then You can see the chain and sprockets. Then just inspect the sprocket for wear and chain tension.