Here are Chevrolet Cobalt engine problems, by model year. The most common Cobalt engine problems cost $3,200 to fix & occur at 54,000 miles. Regarding the worst model year 2006 Chevrolet Cobalt engine problems, "The 2006 Cobalt continued to carry the torch first lit by the 2005 model year. To be clear, that torch is burning bright with widespread power steering issues, electrical curiosities and a dangerous ignition switch defect which led to a massive recall by GM. This isn’t a great torch to carry." Click on a year below.

Worst Engine Problems
ECU failure 2006 Chevrolet Cobalt
engine stalls/shuts down while driving 2007 Chevrolet Cobalt
engine blown 2008 Chevrolet Cobalt