I have 2009 SS with 195K miles on the odometer. The timing chain and water pump chain (and all their pieces (oiler, guides, tensioner, etc)) were replaced at 185K miles by me. I purchased my parts from the OEM supplier, Cloyes. The cam/crank sprockets looked fine and therefore were not replaced. The engine runs fine and has no CEL. It's all stock.

Over the last month or two, I have started developing an unusual rattle during acceleration. I can produce the same rattle in the driveway setting still, by revving to about 2-3K RPM and it seems to be coming from timing chain area. I plan to remove the valve cover soon to inspect. But I would be shocked if it was a timing chain problem since I just did the whole shebang 10K miles ago.

I know the end-of-life sign for the timing chain is cold startup rattle, which I don't seem to have. But has anyone experienced some type of rattle during acceleration?

 

Ping? Try a higher grade gas 93 if you can find it.
Maybe, flex pipe.

 

Serpentine belt tensioner ?

 

Actually, that crossed my mind. Before I pull the valve cover, I'm going to remove the belt and start it for a minute to see if the noise disappears.

 

Hmm, I always run 93, but since I'm a price shopper, I usually fill up 93 at the cheapest location. Maybe next time, I'll try something like BP 93, to see if that affects the rattle.

 

I completely understand being a price shopper.
BUT, does saving a couple of bucks worth the risk of 'bad' fuel.
.10 cents a gallon times 15 gallons = $1.50
Not too me.

 

Good points. But what would baffle me is that this would be the first time in the last 5yrs of ownership that my choice of 93 affected engine rattle (assuming the rattle is from bad fuel). And I'm fairly consistent about what stations I stop at. Additionally, the noise started soft and has progressively worsened over the last month or two. In any case, I can give it a try to see what happens.

 

Please check the flex pipe, whether or not you think it is out of the question.
Air cleaner bracket?

 

Yes, those are good ideas too. Thanks!

 

I just realized this is an SS. Turbo bearings?
A mechanics stethoscope would be handy, they are cheap at Harbor Freight.