2008 Aveo LS Won't speed up above 40 kph, barely shifts into second gear, runs rough

[Colonel Clink]

Hi everyone,
So glad I finally found this forum. I inherited a 2008 Aveo with 16000 km and right away the timing belt tensioner lost its bearing so sounded like a machine gun but I had that fixed under warranty. By 30,000 km the check engine light came on an the fun started. I had the car in the shop 17 times in one month, changed out the coils, plugs, fuel injectors, MAP sensor, Mass airflow sensor, coil wires, etc. Every time the CEL light said trouble with cylinder 2 misfire. A diagnostic specialist said with every Aveo he's seen with this problem, it turned out to be the head needed to be machined or rebuilt as the valve or valve seat was the culprit ($2800 rebuild). After the first $1200, I said enough and drove it with the CEL light on. Adding two cans of Sea Foam as well as a can of injector cleaner actually made the CEL go away, car ran smooth again and misfire went away till now a year later at 51,000 kpm. Today I drove the car with the CEL flashing on and off (as usual for the last week) but when I parked the car it stalled 4 times after starting, then would only creep along till it got up to 40 kph and would barely go faster in second gear after it shifted. Won't go any faster shifting manually, same super duper slow up to 40. Literally takes 3-4 blocks before it will make it up to 40 kph. Do I take it back in to start the whole diagnostic nightmare again or does this sound like a different problem from a cylinder 2 misfire? Possibly MAP senor, Mass airflow sensor or throttle position sensor? Thanks in advance. I like my Aveo but I'm seriously considering puuting it to rest even though the body is great and has so low mileage on the engine.

[avguy]

There are hundreds of separate things that can cause these issues, and there is no way for anyone to know what's wrong without doing diagnostic testing. If you want to attempt this process yourself, start by having the codes read. If not, and you want to try keeping it on the road, take it to a full service shop.

[Colonel Clink]

There are hundreds of separate things that can cause these issues, and there is no way for anyone to know what's wrong without doing diagnostic testing. If you want to attempt this process yourself, start by having the codes read. If not, and you want to try keeping it on the road, take it to a full service shop.

Thanks, was hoping to avoid the 12+ trips to the shop I experienced last time. Going out of country for a week then guess I'll have to get the ball rolling with a trip to get the codes read.