Timing chain, we’ve seen nothing about a ten year thing from GM.

 

Update: the noise is less frequent these days. If it happens, it's only for a millisecond and doesn't occur most startups. Temperatures have come up slightly in NE Ohio, so I don't know if that's a factor or not.


Please elaborate more about this silencer. Is this an aftermarket part? Where is the HPFP located and how do I check to see if this is installed?

 

The HPFP (high pressure fuel pump) is located just above the oil filter service cap area.
The insulator/silencer is a factory installed part.
I removed my insulator years ago when it got oil soaked. Here's a pic that shows my HPFP without the insulator. (disregard the red circle)

 

Lo and behold, my HPFP insulator/silencer is installed and intact, so that's not the issue.

Like I said in my previous post, the issue has been less frequent. So I guess I'm going to chalk it up to weird happenstance and not worry much about it at the moment.

 

I'd like to resurrect this thread since the rattle issue seems to persist, but still only intermittently. Somewhere else online, I was told it might be the cam phasers (i.e., cam sprockets) causing the rattle. And they linked to this web page referencing a TSB:

https://www.cobaltss.net/forums/prob...ecotec-190916/

I wonder if this may be my issue since during the timing chain repair last year, I never replaced the cam sprockets. Does anybody know how to ascertain if the noise is originating from the phasers or do I have no choice but to replace them and hope it fixes the noise?

Additionally, assuming it was the cam phasers, if I ignore it, will it cause engine harm or is it merely a startup nuisance?

(Note, I've had an oil change since I originally started this thread, and I have maintained the correct oil level, so I think we can rule that out)

 

I’m not aware of any way to test the cam phasers, except maybe with the chain removed and moving the phaser listening for metal to metal noise.

ZZP has these take offs available




GM part numbers



Their EBay page.

 

Thanks! Are you aware of any harm that may incur if I ignore the cam phasers (assuming they were causing the noise)?

 

Or go to their website and get them for even less!

https://zzperformance.com/ecotec/cam...in/cam-phasers

 

This is just note on my experience with the eight 2010 -2011 2.4L's I have owned.
All of them were under 35,000 miles when sold.

My first one I bought Brand New. It had the rattle start at about 6,000 miles.
GM replaced the Serpentine belt and it stopped for about 5,000 miles ... then started again. Sold @ 15,000 miles.

All the rest had the issue but it never got to a critical point .... Just there intermittently.

My current 2011 now has 35,000 miles. I bought it @ 27,000 miles.
It had a new oil/filter change with an unkown brand oil from the Chevrolet dealer I purchased the car from.
I drove on that oil for 2000 miles but had the rattle occur twice so I changed the oil and AC filter to Mobil 1 regular.
That is the first Mobil 1 I have used in any of the HHR's and I noticed a difference in the engine immediately. Very suttle but noticeable.
I have only had once rattle occurrence since that Oil Change 6000 miles ago.
I did change the oil again at 3000 miles useage and will continue that going forward.

Also I changed my cold start procedure slightly.

I now turn the key on and let the fuel pump shut off before cranking.
I used to just turn the key all the way to crank without any pause.
Not sure if that is a factor here but it does seem to make a difference... or am I just dreaming???
I do thnk the colder weather has an effect on this issue.

Silverfox

 

I’m not aware of any reports of damage, if ignored.

RJ , those pictures I posted are from an American EBay site , the prices are in Canadian funds so yes the would be cheaper, that’s why I posted the part numbers