2008 Chevrolet Aveo Timing off?

you might have bent the valves but best to scan for codes to see if cam is actually off. see pics for alignment.
Align the timing marks on the camshaft gears.
Install the timing belt.
Fig. 32: Using J42492-A To Rotate Coolant Pump
Courtesy of GENERAL MOTORS CORP.
Rotate the coolant pump clockwise using the J 42492-A (1).
Fig. 33: Aligning Timing Belt Automatic Tensioner Pointer With Bracket Notch
Courtesy of GENERAL MOTORS CORP.
Rotate the coolant pump clockwise until the adjust arm pointer of the timing belt automatic tensioner is aligned to the notch in the timing belt automatic tensioner bracket.
Fig. 34: Aligning Timing Belt Automatic Tensioner Pointer With Bracket Pointer
Courtesy of GENERAL MOTORS CORP.
NOTE: Refer to Fastener Notice.

Tighten the coolant pump retaining bolts.
Rotate the crankshaft 2 full turns clockwise using the crankshaft pulley bolt.
Loosen the coolant pump retaining bolts.
Rotate the coolant pump until the adjust arm pointer of the timing belt automatic tensioner is aligned with the pointer on the timing belt automatic tensioner bracket

I have done all those steps. When I completed it, I put the car together, like I said it started right up and ran fine, except the surging and rough idle. How do I correct the problem? I don't think there are bent valves, I'm thinking timing off. How do I correct it step by step.

it may not be that try cleaning the throttle plate on both sides with choke cleaner and iac hole. then scan for codes to see if there are any and recheck yoru work for a vacuum line off/broken.

I checked codes, come up with a P0300. With the timing off? Will it cauase the surging, rough idle. I did drive it around runs fine with a lot of power.

P0300 is a misfire code and are an absolute pain in the ass to diagnose. as it can be any one of the sensor or injectors in the engine.check plugs and wires, and for vacuum leak if you can clear the code fine and see if it comes back if it does have a pro diagnose this as they are just a pain in the butt to fix. make sure all your duct work is connected as well as wires to sensors

OK, now you still haven't answered my question on how to correct the timing, it's off by about a tooth. Is ok the way it's set?

if it's off you have to physically reset it you can't do it electronically that is why I sent the instructions the first time. if you can get rid of the misfire code it should be ok

On resetting timing belt as per instructions, can I turn cam sprockets back so the marks are facing each other? Left sprocket is the one , that won't line up, and will I damage anything in the process?

i'ts what is called an interference engine so check compression now before you readjust timing belt if any cylinder is not with in 20% then you already bent a valve. you could do that ifnot set up right.

OK Hmac300, I will do that and see if that takes care of issue. Thanks for your help, and have a good day.

I know this is an old post, but did you ever solve your problem?

Hey ROBERT,

Sorry the guy never got back to us. If you get the problem fixed please share so it will help others.

Best, Ken