GMC Acadia Engine Sluggish Due to Cam-Crank Sensors

Had the same symptoms on my 2010 GMC Terrain last summer. The engine light came on during highway driving, followed by noticeable power loss and higher fuel consumption. The crank sensor was failing intermittently, causing incorrect timing between crankshaft and camshaft positions. The problem got worse over two weeks until the engine started misfiring. A diagnostic scan confirmed error codes related to crankshaft position sensor malfunction. The timing chain was also slightly stretched, which contributed to the reference value issues between crank sensor and cam sensor readings. The repair required replacing both the crankshaft position sensor and timing chain assembly. This was a serious repair that took two full days at the shop since they needed to access the front of the engine. The new parts restored proper engine timing and resolved all symptoms, power returned to normal and fuel economy improved. If you notice these symptoms, best to address it quickly before it leads to more severe engine damage. The crank sensor is a critical component for proper engine operation and ignition timing.

Thanks for sharing your experience. My Acadia actually started showing similar symptoms, poor acceleration and high fuel usage. The misfire got pretty bad before I finally got it fixed. Just wondering, do you remember the total cost for the timing chain and sensor replacement? Also curious if youve had any other timing-related issues since the repair? Mine's been running fine for about 6 months now but always good to know what to watch out for.

Happy to report no timing issues since getting it fixed. The repairs were much simpler in my case, just needed the crankshaft sensor replaced which cost 340 Euro total including labor. No timing chain replacement was necessary like I initially thought. The mechanic confirmed the crankshaft to camshaft reference value is now reading correctly after the sensor replacement. The engine runs smooth again with normal power and fuel consumption. Really different from the sluggish performance before the fix. Keeping an eye on engine timing is important, if the cam sensor or timing belt starts acting up, the check engine light usually gives an early warning. But six months of trouble-free running is a good sign that your repair addressed the root cause.

Wanted to wrap up my experience, finally took the Acadia to a different mechanic shop last month. The crankshaft sensor was indeed faulty, causing those timing issues. Total bill came to 580 Euro including parts and labor since they had to replace both the crank sensor and cam sensor to restore proper timing. Shop got it done in one day and the engine runs like new now. No more misfires or sluggish response. Fuel consumption is back to normal too. Really glad I switched mechanics, these guys actually explained the problem and fixed it right the first time without trying to oversell unnecessary repairs like a timing chain replacement.