Does timing chain go bad?

Timing chains usually last as long as the engine does, however they can stretch due to poor maintenance or guides go bad causing damage if let go too long. The way too check the chain is to bring the engine up to TDC and then check the timing marks from the crankshaft to the cam gears, if the marks line up to the specs then you chain is fine. Now if you hear a clacking sound when you first start a cold engine then you have a chain adjuster getting weak. Hope this helps

Thanks. Do extended 5-7k miles 0il changes help or hurt?

Do not exceed 5000 miles on oil changes in a normal environment if using full synthetic oil. 3000 is using conventional oil. And stick with what is recommended on oil weights.