I just went through quite a large job of replacing both balance and timing chains, all new guides, etc.. along with the water pump as well. I did make a mistake and thought I had the tensioner activated when indeed I did not. So I pulled the valve cover back off and confirmed it was loose. I managed to get it tensioned and back together and it's still on startup making the same squeaking sound as well as now doing it when I blip the throttle. There's absolutely a chance I made a mistake since I was doing this outside between storms and at night with flashlights since I've had friends and family visiting constantly for the past 5 weeks and staying at my place! However, I can confirm that my timing marks are correct and the car drives well. To confirm the timing, this is the new timing chain:





I can try and get a video to share what it sounds like, but it's dark now and I'm hungry.

 

The rain stopped and I managed to take this short video. You can hear it on startup as well as when I rev it. I'm reving it to ~2500-3000 RPM, not that hard.

 

Do you get any codes? Is it distinctly different than the HPFP ticking?

 

There's currently no codes. I can hear the HPFP ticking, this other sound is distinctly different. It's definitely what I was hearing prior to doing the timing chain.

 

So I had some time this weekend to look a bit more into the sound I wa shearing. There are two sounds, at cold start there is what I thought was the timing chain sound, but I believe it may just be oil pressure getting into the hydraulic lifters. That sound will go away once the engine warms up a bit. Perhaps after 100k+ miles a few are gummed up and take a while to gain pressure? If I stop and start the engine shortly after, the sound is gone.

The other sound is definitely a very loud tick coming from HPFP. I've confirmed it's definitely the HPFP. This sound comes on when I start the car, remains for a few minutes and then simply goes away. After that I have just the normal tick of the DI.

I'm still trying to read up and investigate further as to what my be causing this. In the meantime, I'm keeping my driving on my Cobalt at a minimum and keeping boost low while driving.

 

Have you cleaned the intake valves? Could be something sticky going on there, and if you haven't done it yet it would need it regardless.

 

Did you go with a Cloyes/OEM timing chain kit? I went with store brand one time and the guides were out of spec and the top guide metal actually rubbed on the side of the chain. Also a roller broke on the chain itself. I learned my lesson.

 

I actually just did the intake valves just under a month ago. So I know everything there is all squeaky clean.

I did use the Cloyes chains I purchased with upgraded bolts and updates tensioner from a forum member here. Using a solid piece of metal to listen around the engine I can hear the chain running smoothly along the guides. So I don't believe that's the issue.

When I did do the timing chain, I did find one of my valve lash adjusters was shattered. So I replaced that. I also had two other's fail about 40k miles ago when I over revved the engine. I wonder if there's a possibility that others are nearing failure. They were all on the exhaust side. (Cyl #1 and #3).