One problem related to engine clicking and tapping noises has been reported for the 2008 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 GMC Sierra 1500 based on all problems reported for the 2008 Sierra 1500.
Ticking noise began once the vehicle reached ~100,000 miles. Initially, the ticking only occurred once the engine was started. As time went on, the ticking became more frequent, to include upon engine start and while the vehicle was under load/accelerating. At approximately 108,000 miles, the tick became constant while the engine is running. GMC dealer diagnosed the problem as a failed lifter, which, apparently, has been a common problem in gm 5. 3l engines. A vehicle should not need a new engine, or even new lifters for that matter, at 100,000 miles. This is a known issue, with many consumers reporting it and gm acknowledging it. Vehicles with these engines should have been recalled years ago.