Engine performance is not good

[drmagieed]

my ecotec engine acceleration was not good and its sound was rough somewhat. I changed the oil with castrol edge 10w-40 and the sparks plugs with ngk laser iridium IZFR6F11 and I am using acedelco green coolant. My engine is about 26 k miles.
What are the possible causes for that?

[drmagieed]

I feel that my engine loose some of its power. What I can do?

[jamesd]

What year is your Aveo? Is the engine running rough when it's idling? or also accelerating? Any check engine lights? If there are no check engine light I would start with vacuum hoses. Based on my 2005 1.6 engine There is brake booster hose, two small hoses going to the intake manifold. I would also check the air cleaner hose, the one of the passenger side of the engine compartment that connects to your air filter box and throttle body. They tend to develop cracks and holes on these hoses. Plus it doesn't cost anything to check these items.