Hi, I scanned for any codes, there are none, never had a CEL light on, (it comes on at start so I know the light works).
This is a 2007 Solstice GXP, 2.0L, manual transmission, no tune, no engine work, all stock. Air filter and oil changed yearly, about every 6,000 miles. Always use premium gas. Currently have 61,000 miles on the car. Usually driven about once a week and when not, kept in garage.
From about 1900 to 1950 rpm the engine runs rough, I would even say it is missing, it is that rough. From idle to 1900 and from 1950 on up smooth as silk. This happens when only maintaining speed, not accelerating, when accelerating, at any rate, through this range I notice no roughness. When decelerating through this range I notice no roughness.
I would say it is getting worse very gradually. Noticed it early last year, but could not really tell from running rough to road conditions, now my wife notices it too. The rpm range for the roughness has not changed. This happens hot or cold, happens right after start up and will continue all day during hours of driving.
Mechanic suggested to try Seafoam. I now have a can in the car now, half a tank still to go and no change.
Replaced the battery this last January, so I believe you can consider the ECM to be 'reset' then.
Any thoughts or suggestions?
Thanks,
Tim.
