donbrew

Yeah, and if any sensor is doing its job the computer MUST be what is wrong. The ECM being the actual problem (not connectors and wires) is 100,000 to 1. Any thread you read on the interwebs that mention it is because in the description of possibilities the ECM is mentioned as a very last possibility. Dealerships make their money replacing thiongs so, the mechanics focus on the easy stuff.
The ECM does not "control" the sensors, for the most part they are passive coils of wire. More likely a loose connection, a frayed wire or a blown fuse than a bad sensor or computer. The computer only reads data and adjusts things; garbage in, garbage out.

Shadetree

The code is P0016 so I guess it's the timing chain.

Thanks for the help everyone. I'm not sure when I can get to it, but I will update after I do.

Oldblue

Do not drive the car or start the engine, P0016 is definitely the timing chain is off at least 1 tooth. If it skips any more then it could bend valves and damage pistons!

Shadetree

Yeah, it will just sit there till I can deal with it. Thanks

Bonez

If you just bought it, did it come with a warranty? usually 30 days or 3 months/3000 miles.... Id get the dealer to fix , foot the bill or reimburse costs.....

Shadetree

Nope, as is. The dealer is like a cricket. One of those buyer beware situations.

Oldblue

If you are changing the timing chain, install a replacement bolt in the front guide upper bolt .

https://www.chevyhhr.net/forums/how-...in-kits-60394/

https://www.chevyhhr.net/forums/how-...de-bolt-62897/

Shadetree

will do

donbrew

In the US, unless otherwise stated in writing all used car sales are "as is". Same with any "used" item.

PulpFriction

Did you really replace the camshaft sensors on the front and the back of the head on the driver side, or were they the VVT solenoid valves on the top of the head on the passenger side that so many mistakenly call sensors?

Back in 2008 ChevyMgr posted a list of C and P codes for HHR. The descriptions for P0016/17 (wisely) do not include the word sensor there.

• P0016 Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation
• P0017 Crankshaft Position (CKP)-Exhaust Camshaft Position (CMP) Correlation

But all over the web they do use the word sensor, apparently causing massive confusion. Here’s a more lucid one: “The correlation of the camshaft and crankshaft positions on bank 1 is incorrect based on the intake camshaft position sensor..”

For the life of me I don’t know why people conclude that that means a sensor is bad. How could the computer know the correlation is wrong unless the sensors are working? Surely tens of thousands of sensors are pointlessly replaced because of this confusion.

Ref: https://www.chevyhhr.net/forums/prob...010-hhr-14259/

OK, it was only P0016. But since it now won’t even start, the chain has jumped more than the one tooth or two that just made it run bad. I would not decide on a complete chain job until I knew if the valves have crashed. I’m not sure how to do that. Oil on one plug? Maybe just bite the bullet and pull the head.

It is plausible that gummed up VVT solenoid valves or actuators could cause a P0016/17, but really rough running is surely a jumped chain, and a crank no start could mean it’s too late for just a chain job.

I think GM should reflash all EcoTec ECM’s so that a P0016 or 17 goes to an immediate flashing CEL and won’t allow the engine to be cranked if a restart is attempted.