My cobalt ss makes a rattling intermittently at start up and is only heard outside the car. Coming from the Timing chain side of the engine. In addition it makes a knocking noise while driving at about 2200 rpm to 3000 rpm, usually after sustained driving and usually under load. Seems to clear out after I get it to knock a few times and raise rpms. My guess is timing chain and tensioner, but any information would be helpful thank-you in advance.
Supercharged ecotec 2.0 knocking rattling
Remove the serpentine belt and tun the engine, if the noise is still there, then it is internal in the engine.
If the noise is coming from the timing chain area, then I would say your on the right track in thinking chain tensioner. Only way to be certain would be to start taking it apart.
Comments are closed.