So this is my sisters cobalt. She had the engine replaced due to a broken rod last summer.. This engine has around 90k miles on it. I just changed oil a week and a half ago and it started making this noise. I don't think it's related to the oil change though. Popped the valve cover off and took the top chain guide off.. Timing chain seems firm not much slack at all. Cam, rockers, springs, etc.. Seem all ok. Could it be lifters? Anything these engines are common for?

Here's a video of it.
https://www.youtube.com/watch?v=6jFw...ature=youtu.be

Thanks in advance

Oh it's an 07 2.2L

 

The chain should be tight

Replace the timing chain tensioner

 

You think the tensioner would sound like that?

 

I mean it seems tight... I don't think its the tensioner.. What else could it be?

 

Every single timing chain tension from the factory was faulty. ( in the early years anyways )
They clatter and sound like ****. Very common, like changing tires, we've all done it.

Before the revised version of the ctc I've read threads of guys going through several of them within a year of owning their cars..

 

I'm not doubting you a bit man, just every tensioner I've dealt with never sounded this bad (though never done one on these cars before either)

 

I hear ya, do some googling. If it snaps your in for a **** storm. Mine was periodic clatter at start ups ( caught it fast ) there's tons of videos . Hold a Long screw driver to it and cup it to your hear, if you hit the problem spot you will knkw

 

That's the problem I have a mechanics stethoscope and it sounds all over lol. I'll throw a tensioner on today. If it doesn't get better at least I'll know that's not it. Going to the shop tomorrow if I can't figure it out. Just don't want her to pay out the ass to get the head pulled

 

Best of luck, report back !

 

Well, not the tensioner

 

Next thing would be the chain guides. There's quite a few of them, you can buy kits and they do fail, you wouldn't be the first.

But next thing i think would be to remove the timing chain cover on the motor. Give you a full view of the timing system. Maybe wait for a second opinion, but that's where I'd go. Pretty easy over all , little time consuming, but definaty do able with basic tools and mechanical know how. The crank sprocket will need to be taken out, but almost any auto shop would lend you the required tool.

Sorry that didn't work out, the tct fail like no other, more times than not that's the cause of the rattle .

 

Now I think its in the head. Did notice a rocker I could push up and down pretty easy opposite of the roller tip side (lifter side) hopefully if it's in the head its just faulty lifters and not a bent valve or something