Has there been any progress on the timing chain replacement? It looks doable from the video with the engine out and easy access. Can this be done in an HHR with the engine in?
I took my 2011 HHR with 94,000 miles on it to a garage for rough idle after warm up diagnostics. No OBD2 codes present and no CEL. They told me that it needed coils and an exhaust solenoid and recommended an timing chain replacement including the water pump replacement for $1650.00. They said it would take 3 days because they would need to drop the engine. I feel like I should take it someplace else. I think I've seen a labor time of 6.5 hours on another post.

 

Problems with coils or the exhaust solenoid would generate a fault and light up the CEL. And since there are 4 coils, what are the chances that they all go bad at the same time?

And of course the timing chain job can be done in the car.
Yeah, find another shop.

 

I would ask them "why?"; maybe they saw something. However, without some evidence of a need of anything past a throttle body cleaning, they are reading off the recommendation by mileage sheet. In other words, they are not competent enough to do diagnostics for themselves.