Rough Idle Issue for Chevy
This bulletin applies to 2004-2009 Chevy Trailblazer, Hummer H3, 2004-2012 Colorado, 2004-2012 GMC Canyon, 2004-2011 GMC Envoy with an inline four-, five- or six-cylinder engine. Some customers may complain of an engine belt noise, rough idle and/or SES light on. DTC P0014 and/or P0017 may be set. If a rough idle is experienced, P0106 may also be stored.
Inspect the camshaft actuator solenoid screens as shown in the accompanying illustration. If any of these screens are missing, replace the camshaft actuator solenoid, change the engine oil and filter and re-evaluate the concern. If none of the screens are missing, proceed as follows:
Measure the crankshaft endplay to determine if it is within the specification of 0.0044” – 0.0153”. If crankshaft endplay is only 0.001” or so above specification, it is probably not causing the concern. Typically, if crank endplay is causing the concern, it will be obviously out of spec by as much as 0.050” or more when a pry bar is used to move the crank back and forth.
If crank endplay is acceptable, replace the camshaft actuator solenoid and re-evaluate.
If the crank endplay is well beyond spec, GM recommends engine replacement due to thrust bearing debris that may remain in the engine.