Wife started the car up and it started this the whole day. Night before car drives fine and sounds great. What would cause this overnight and no engine light is on either? Its doing this as if there is a miss.

 

Random misfire not triggering the CEL yet, possibly.

 

It's happened to me randomly, once or twice, a misfire on startup and it keeps chuggin along like a V8... car ran fine, I could only hear/feel it inside the cabin and at the muffler (Not under the hood).

 

did it almost sound like you had cams or as aachshun said a v-8? Mine does it time and time again, but it never triggers a cel. I wish it would theough so i know what exactly to change and et it replaced.

 

CEL just came on today. gonna find out whats going on. This car has been pretty good to me. Only serious thing was the valve cover gaskets and the coolant temp sensor that needed replacing and that was about 3 years ago.