p0300 no overdrive

[dcasey]

2004 aveo 1.6 auto trans. Engine blew replaced it
then got the three codes and no overdrive. Ran
good, but no overdrive drove it for about three
months then timing belt went and Bent valves.
Replaced head with brand new from gm. Runs very
Good but same issues the three codes and no overdrive.
Please help car runs to good and to much money into now
Have to keep it. No highway driving turned my 30 min drive
To work turn into almost an hour.

[avguy]

You said 3 codes - what are the other 2? You didn't include the elapsed time for some of these events, and it would be helpful to know how fast these things happened. How long after the new engine went in until the first CEL, and did the misfire code show up right away? How many miles after the new engine went in until the timing belt problem, and do you know for certain which timing component failed? Did you do the timing belt both times, or was it a shop doing that job?
The timing belt job that was done when the engine was replaced should have lasted at least 60K miles, and anything way short of that would tend to make that a likely suspect. If so, I would suggest first checking to see if the timing marks are correct now and the belt is tensioned properly. If everything's ok there, then it's on to the next steps in the diagnosis.

[Aveo5_boy]

I know from reading Daox's thread on another forum with the p0300 code after engine replacement he had the crankshaft relearn done which eliminated that problem. Daox would probably have more insight with this problem since the engine on the OP's vehicle has been replaced.