04-07 cts timing chain
 

Hi all.....I was thinking about buying a 05 cts. I was going to buy one from a man that says it needs a timing chain as the engine is noisey...I have no problem doin the work myself. However I don't know much about the cts. I'm wondering if there is a reason why I shouldn't get involved with the project. After I change the timing chain will the engine noise be gone or is there a chance that there is permanent engine damage from not changing the chain before the engine noise started??...any info on this is appreciated

It is an interference engine if chain jumps valve(s) will get bent. Bent valves should set ses light and misfire codes. If its just a worn chain replacing chain, guides and any other worn parts should make noise go away. Bent valves usually leads to engine replacement