rack up another issue

[time4newtruck]

2009 gmc sierra 5.3 none flex fuel engine w/ displacement on demand(DOD) NO MODIFICATIONS------------------------------------------------------------------
Over the past few months I have been noticing a tapping/clicking sound coming from the truck. I would describe it as small stones hitting the metal wheel well, however its the same pitch at all speeds. Following shifts the engine seems to be idling up abnormally fighting the DOD cylinder shutdown. While the engine idles up (with foot completely off pedel) the click/tap can be heard. Also when approaching a stop truck will down shift and idle up to just a little over 1250 rpms on the tack. The engine will idle up as if I was to rest my foot on the gas pedal then goes back to normal idle(600-700rpm) I have not noticed this idling up issue on any of the same generation sierra/ silverado. Truck is still under warranty however there is no check engine light on. please help

 

[GMC Customer Service]

2009 gmc sierra 5.3 none flex fuel engine w/ displacement on demand(DOD) NO MODIFICATIONS------------------------------------------------------------------
Over the past few months I have been noticing a tapping/clicking sound coming from the truck. I would describe it as small stones hitting the metal wheel well, however its the same pitch at all speeds. Following shifts the engine seems to be idling up abnormally fighting the DOD cylinder shutdown. While the engine idles up (with foot completely off pedel) the click/tap can be heard. Also when approaching a stop truck will down shift and idle up to just a little over 1250 rpms on the tack. The engine will idle up as if I was to rest my foot on the gas pedal then goes back to normal idle(600-700rpm) I have not noticed this idling up issue on any of the same generation sierra/ silverado. Truck is still under warranty however there is no check engine light on. please help

time4newtruck,
I would suggest that you have your dealer look into this issue for you. They are in the best position to get this diagnosed for you. Please keep me posted on this and if you have any questions, comments or concerns please feel free to contact me anytime.
Thank you,
Stacy GMC Customer Service