GMC Acadia Engine Knocking and Power Loss Fix Guide

Had similar symptoms with a 2010 GMC Terrain 3.0L. The engine knock was quite noticeable during acceleration, and the knock sensor kept triggering codes. After inspection, it turned out carbon deposits in the combustion chamber were causing serious pre-ignition issues. The fix required a thorough combustion chamber cleaning and fuel system service. The carbon buildup was affecting proper fuel combustion, leading to engine knock and power loss. The piston slap sound was initially misleading, but the real culprit was heavy carbon deposits interfering with proper combustion. Engine tuning was also necessary after the cleaning to ensure proper timing and fuel mixture. This prevents future deposit buildup and maintains optimal combustion chamber conditions. The repair was significant since carbon deposits can cause long-term engine damage if left untreated. Key signs it was deposits: White/gray smoke from exhaust, Rough acceleration, Drop in power, Consistent knock sensor warnings, Poor fuel economy Would recommend getting it properly diagnosed soon, as these symptoms typically worsen and can lead to more expensive repairs if ignored.

Thanks for sharing your experience with the carbon deposit issue. That sounds very similar to what I am experiencing with my Acadia right now. The symptoms match exactly, especially the rough acceleration and smoke issues. Did you remember approximately how much the cleaning service and tuning ended up costing? Also curious if switching to higher fuel octane helped prevent the problem from coming back? My knock sensor is still triggering occasionally and I want to make sure I address all potential causes this time around. Has the fix held up well since the repair? I might need to bite the bullet and get this sorted before it causes more damage to the combustion chamber.

Based on my earlier case with the GMC Terrain, I went ahead and had the repair done. Total cost came to 425 Euro for a complete combustion chamber cleaning service that resolved the pre-ignition issues. The fix has worked perfectly, no more knocking combustion or performance problems since the service. Switching to higher fuel octane definitely helped prevent carbon deposits from returning. Started using 93 octane fuel and noticed better ignition timing and overall engine performance. The knock sensor hasnt triggered once since the repair. Looking back, getting the deposits cleaned from the cylinder heads was worth every cent. The engine runs smoother, and fuel economy has improved significantly. If your symptoms match what I experienced, addressing it now will prevent more expensive damage to the combustion chamber components later. The repair has held up great for several months now. Regular maintenance and better fuel quality really make a difference in preventing these issues from returning. Would definitely recommend getting yours checked out before the carbon buildup causes more serious problems.

Thanks everyone for the helpful advice. Finally took my Acadia to a repair shop this week and had them do a full diagnosis and cleaning service. The mechanic confirmed heavy carbon deposits were causing the pre-ignition and engine knock issues. Total repair bill came to 480 Euro for the combustion chamber cleaning, fuel system service, and engine timing adjustment. The cylinder heads needed extra attention due to significant buildup. While not cheap, the difference in performance is remarkable. No more jerking during acceleration or visible smoke. Made the switch to higher fuel octane as suggested. The engine runs much smoother now and the knock sensor warnings have completely stopped. Should have done this sooner instead of waiting, but at least the problem is fixed before it caused major engine damage. One week since the repair and the car feels like new again. Good lesson learned about not putting off these kinds of symptoms when they first appear.