This is not a simple engine. Every oil change we'd pull the stupid plastic cover and just look at the top of the engine, attempting to ID components and only partially succeeding. It didn't matter, because in all the miles under the wheels, we only had one problem, and that was likely from our cross-country-north-to-south-border marathon. We swapped oil filters at 24,000 miles as advised, but at 39,000 (roughly) miles we were climbing a grade with the Jeepster in tow in 90-degree weather going from 2500 to 7500 ft of elevation and the Grand smelled hot. We pulled over and it died showing an ETC (electronic throttle control) error. We pulled fuses, checked this and that, and about 20 minutes after dying, we were able to restart it and make the rest of our journey. The root cause was a clogged air filter. The tech that worked on it said that it wouldn't have been too much longer until the filter was pulled into the turbo. For our part, we were happy that $20 solved the problem.