I have a 2011 HHR 2LT with 215,000 miles, pretty much all highway miles. I do routine maintenance, oil changes, OEM iridium plugs, etc, and only use top tier gas. The problem I have been experiencing started out while driving with traffic, the accelerator seemed like it had a "dead" spot, you could attempt to speed up, but nothing would happen until it kicked into passing gear. This has gotten worse lately when I pulled out of a gas station into traffic and the car would not accelerate at all until I put the pedal to the floor, then it dropped back to 1st and accelerated like it should. The engine does not rev when you push the accelerator, so I'm sure the tranny is fine, and no CEL is activated. Is there a throttle position sensor going bad, or something else I can check?

 

Any bad sensor would cause a CEL. There are times that a stretched timing chain does not cause a code.

You might pop the valve cover off and see if it looks loose.

Maybe a dirty throttle body, or extremely dirty air filter.

Maybe stop by an auto parts place and have them check for stored codes.

 

I took it to the dealership, thinking that they may have seen this issue before, and I was right. Two other HHRs had come in with similar complaints. Bad news- they couldn't replicate the problem with those two either. One plus, at least they didn't charge me, but the problem replicated itself all the way back home. I did spray the heck out of the throttle body and put fuel system treatment in my tank, but I haven't driven it enough to see if it made a difference. I will let you know if this situation changes, or if I figure out what is causing this. Having a 2 year degree in automotive, you would think I could fix this myself, but unfortunately, I graduated during the dinosaur/carburation period. These computer run cars drive me to drink...

 

Or, you are over thinking because you think computers are magic. If there are no DTCs the computer is not involved.

Could be the pedal is bad. (mechanically)

 

Don gave you some ideas, try one at a time!

 

Also, and yes this is a pretty basic thing, but check your carpeting/floor mats to make sure something isn't wedged.

Had that happen on wife's Kia once.

 

The only thing I haven't done is remove the valve cover to check the timing chain. I'll have to wait for a weekend for that because this is my daily driver. I drove it to work yesterday, 220 miles round trip, and it seemed a bit peppier, but there was still a definite feeling of a dead spot on the accelerator. I don't have carpeting, so nothing is physically restricting the pedal.
A good point about over-thinking, although I've NEVER been accused of that, with no CEL it shouldn't be a sensor or computer issue. I'll keep hammering at it until I get it sorted out. I appreciate all the advice!

 

If P0016 pops up, that's the timing chain. But I've seen a chain fail without setting off a code!