My car still makes this awful chatter when I've driven it a while, got it good and hot, parked it... waited about 20 mins or so and then got back in started it and idled.

It sounds like a metallic chatter. Here is a video

YouTube - 2006 Cobalt SS Engine Noise

I have taken it to the dealer when my warranty was in an could not reproduce the noise with them. I seriously need some help figuring out what it is. It sounds like a lifter not pumping up. I am scared to drive it in fear of chewing up my cam.


Any thoughts? Now my warranty is up, but I already have a case with GM about it so I should be covered if I can replicate it somehow at a dealership. It happens every single day but I work too late to take it when it happens.

Help me out guys.

 

Halp?

 

did you check the timing chain tensioner? pretty common thing for ss.sc

 

Sounds like my GTP did when I installed 1.9 rockers and one of them was hitting the valve cover haha, a dremel to the vc fixed that. Obviously that's not your problem since the motor is a different design but I'd bet a dollar that it's valvetrain related, maybe a sticky lifter? I know the timing chain tensioners go bad but it seemed to be quieter in your video when you moved over to the side that the timing chain is on.

Do you have any aftermarket valvetrain components? Valvesprings or lifters or something?

 

I dont think that is a valve rocker or anything like that.

 

Its not coming from the front of the engine. I cant get it to do it at the dealership
I feel so foolish. I've been there over 20 times now. Seriously. The expect me every friday morning now.

WTF should I do. I want to take the VC off and take a look. Can I reuse the gasket?? What would I need to watch out for?

 

Yous should be able to just make sure you don't tear the gasket when you take the valve cover off.

Look for any spots that look like they're being rubbed on. You'll be able to tell if something is making contact the bottom of the vc.

 

It's the timing chain tensioner I believe.. my moms van did the same thing, but only sometimes and on certain start ups. Also like someone pointed out the tensioner is a likely cause.

 

but the front of the engine is silent.........

 

dot dot dot

 

moved!

 

If they expect you on Fridays then take it in on Thursday and your car will do it for you
Just joshin ya.
But seriously mine makes a chatter sound but it's when I first start it and after it warms up it's fine, so I do truly believe mine is valve chatter or a stuck lifter or some **** like that, who knows, it's done it for a long time now.

 

can this stuck lifter pit my cam??