Chevrolet Cobalt 2004–2006 — technical service bulletin
Bulletin 3644 · NHTSA communication 10018532 · issued Jan 5, 2006
Technical service bulletin
communication type
Engine and Engine Cooling
component
2004–2006
model years
5
vehicle entries
Official summary
Momentary sag on light to moderate accel when cold - valve deposits. *tt
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.