According to this GM service note, there were different
intake cam parts for 2011 Regal LAF 2.4 engines (early 2011 vs. late 2011).
The
VIN number can reveal if the engine is early or late (I don't know if the RPO codes help).
Of course, some warranty work updated early LAF engines with newer
intake cam parts, so it is never that easy.
"A 2010 engine has a black exhaust actuator sprocket and a gray
intake actuator sprocket. Each camshaft actuator sprocket will have a different part number.
The
intake camshaft is for a 2010 model engine.
A 2011 LAF engine has black camshaft actuator sprockets for both the
intake and exhaust camshafts. Both camshaft actuator sprockets will have the same
part number. The
intake camshaft is for a 2011 model engine.
Note:
If working on a 2011 Regal LAF, the technician must identify if the engine is an early or late build design. Early build is a 2010 design and a late build is a 2011 design. 2011 model year Regal's Built Prior to last eight of the
VIN B1014160 have a 2010 design engine (both camshaft actuators are different colors and part numbers and it has the 2010
intake camshaft). Any 2011 Regal LAF built with that
vin or newer will have a 2011 design engine (both camshaft actuators are both black in color with the same part number and it has a 2011
intake camshaft)"
-->
Intake cam to sprocket was changed at some point but I don't know if this is related to the early/late 2011 change (10 vs 5 O'Clock "marks" on the cam with the sprocket removed). Exhaust was at 7 o'clock and not changed AFAIK.
--> I don't remember when the balance chain revision was done but I thought that would just make things run rough but not throw a code.
