I have a problem that i'm not sure how to get a tech to check out...i have decribed it and they couldn't come up with anything other than you must be hearing the superchargerLOL. It only happens when the car is warm and at idle. Sounds like the timing chain or something is rattling like a snake. Anyone else have this simular noise????


NOTE:
I know their was a thread about the knocking on startup glad for the insight their although inconclusive but its just nice to know that I'm not the only one hearing that knocking but that isn't why I am posting.

 

sounds like the issue i had, my timing chain was stretched out.

 

my s/c rattles like marbles when warm and idling on occasion. plastic couplers I think?

 

Sounds like the timing chain tsb they have out. https://www.cobaltss.net/forums/general-cobalt-68/secret-tsb-i-thought-everyone-should-know-about-54519/

Yup. Get this, much better than the oem parts. http://www.zzperformance.com/cobalt_...=155&catid=142

 

I have the exact same noise, it only does it on cold starts and only lasts til the coolant hits 110+ degree Car has 3995 miles on it

 

could be supercharger coupler, if they say its coming from the s/c..

if its not and they are just really stupid, its could be the timing chain.. heard of that alot.

 

I have the same thing, i just bought a new timing chain tensioner from Crate engine deopt, when it gets here ill do a install with pics, im hoping that will be the fix because it seems alot of members have this problem.

 

Yes please..

Im also checking:

flex pipe
header bolts
header gasket

 

most likely your timing chain tensioner

 

yea it sounds like its coming from the left side of my engine...

 

I know i have posted this before, but does it sound like this?

http://www.youtube.com/watch?v=nEPw78lAPl8

That is what my car sounded like and whenever i go to the dealer they just push me away and told me to come back once i knew how to replicate it, o well! I haven't heard it in a long time but i know i just jinxed myself

 

thats the noise mine made

 

mine was making the same noise. but have not heard it in a while.

 

mine sound nowhere near that loud, WOW !!!

Mine is noticable but not loud at all....goes away fairly quickly

 

That is the same noise mine made. GM dropped a new engine in for me.

 

Mine sounds like that, but at a 1/4 of the volume..

It doesnt do it all the time at idle, but getting more noticable...

but i also notice it gets louder as rpms get higher, and when i shift, it goes away almost to nothing..

 

This is not my video, but that is exactly what mine sounded like and it was about that loud too. I found it on youtube when i was trying to figure out what was wrong with my car. I haven't heard it in about 2 months, it mostly happened during the summer time. There have been tons of treads addressing this problem and for most of the people it was something to do with the timing chain

 

This is soo helpful. I'll have to record the noise next time. Althought not as loud as the youtube video I have not gone further than to recognise a sound and complain to the stealership. I'll have to lift the hood to see if it is that loud only ever heard it at a stoplight or first startup occassionally with no music on. I'm just glad i'm not the only one.....that's a biggy. I drive my cobalt hard when i need it to perform:0) other than that i'm a smooth driver.

Thankyou all!

hope to hear how the other projects work out.

 

Most people think it is the timing chain tensioner but mine was the serpentine belt tensioner. Here is what it sounded like.

http://myspacetv.com/index.cfm?fusea...deoid=43649997