Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Sounds like a coil may be dropping out I have seen coils emit enough RF interferance to cause gauge malfunctions. If happens long enough check engine light will flash. Should be able to catch with scan tool. Ground wires and battery connections are another cause. Take a general look around under the hood wire routing battery cable tightness, give them a wiggle anything out of place. hope this helps. please let me know if there is anything more I can do.
How is the cobalt doing have not received an update. Please remember to rate my service and accept Thank You.