Hello I have a 2008 cobalt lt1 with the 2.2 and auto transmission. Currently has 200k miles and I have noticed some noise on startup that I'm not sure what it is.
Hoping someone could help me, I should note I have one of those thinkcar scanners and everything shows fine. It checks all the modules including trans etc, no codes and 0 misfires. I have recently replaced all spark plugs and air filters.
Here is the link, thanks for any help..
If it's a rattling noise only on cold start up, it's probably the timing chain, tensioners and guides.
It does get quieter about 30 seconds to a minute after startup but even if I turn the car off and turn it back on two minutes later it'll still do it. Could it be lifter noise? (not sure if you can see/hear the youtube video above. Let me know if you can't) one of my friends mentioned a oil pump beginning to fail.
Sorry, I'm a novice at working on cars. Give me a computer, sure I can fix it. Big mechanical machine? Not so much.
Thank you for the response by the way, appreciate you taking time out of your day to help me.!
It might also be an idler pulley or fan belt problem, hopefully.
Is it the starter hanging up ?
I just put a new battery into it last week because the old one was failing, it starts pretty much instantly now with no hesitation. Just clangs/knocks for a little while and it's scaring me. If I drive for 20 minutes and listen to it after it's fine. Turn the car off/on again and it does it again.
Gonna get a fresh oil change on it, also gotta replace axle seals. Will also get the idler belts and pullys checked, just hope it's not the tensioner. Looks like a big job.
It definitely sounds timing chain related. Cold start will always be the loudest under that condition and once oil pressure is achieved it builds pressure to the chain tensioner and the noise goes away.. make sure your oil is full and clean as well
