THAT timing belt is not simple. Ever done one? I've done a few. Hyundais are simple, that one is not with the two cams and the tensioner. It's not like the ones where you crack the tensioner loose, slip the belt off and back on and you're done. You have to align it, clip the belt on to one cam, align the next one and hold that, then set the tensioner, rotate it a bunch of times... at least 2 hours with all the accessories and the cover. I'm sure there were guys that could do it faster but you can't rush timing that thing, you'll bend all the valves. I remember the last one I did, it was a cam code, Px116 I think it was? Water pump blew up, coolant everywhere, (inside the cover) timing belt was soaked and jumped. No typical outward signs of coolant leakage either, just the code.
Plugs on those were a ***** actually. And there was that stupid two piece plenum. And trust me, doing ANYTHING on a Pacifica with a 4.0 (same as the 3.5 just larger) was difficult. I've done many jobs on those things from engine mounts, engine rebuilds, transfer cases, etc. The engine was always the problem, it was in the way of everything because of it's size.
Really, are they THAT bad? I think that they are. For all the complexity it's performance is really pedestrian. I don't know if they had a bad reputation but I guess for me, I just thought they were poorly executed. Why did they keep it around for so long? Because they invested zillions in development and tooling, then zillions more trying to improve it because they knew it sucked. Eventually they threw in the towel and retired that design. The 3.6 went to a timing chain which was no simple thing either until you do them a lot but they were more robust than the 3.5 for sure.
