I recently purchased a 06 Cobalt that was a flood car. It has evidence of water ingestion. The engine intermittently has a misfire #2 cylinder error. Runs pretty well, there does seem to be a slight shudder around 1200 rpm that goes away above that rpm. Ran a compression test and all cylinders show 200 except #2 which shows 150. Also measured the top of the piston height of all 4 cylinders and #2 measures a tenth of inch less than the other 3. I believe I have a slightly bent rod and am considering swapping the motor out. I do work on cars for a hobby, but have never removed an engine. Am I getting in over my head by attempting this? Thanks, Don

Update, Since my last post the transmission starting acting up, not shifting into 4th gear. The engine was running well, bent rod and all. Rather than tear into the engine and tranny, decided to pull the whole powertrain out of the car and replaced with one from another 06 w/ 7K miles that was totaled. It came out the top w/o too much trouble, had to remove the a/c compressor and master cylinder to have the neccesary space to get it out, but doable in a garage w/ an engine hoist. Got the new one in and so far all is well!
http://img208.imageshack.us/img208/4/cobaltenginesw8.jpg