Originally Posted by TmanP
That would be a pretty long list... many transverse V6 would fall under that category, for sure. Off hand, two I remember - GM 3800s are very tight, so many people unbolt a motor mount and tip the engine forward. Tthe Sienna's 2GR-FE back plugs are completely hidden; the intake manifold usually comes off to replace them.
I've found W-bodies with the 3800 to be pretty easy actually. It's pretty much any GM car with the 2.8, 3.1, 3100, 3400 60 degree v6's that usually require a special tool to tip the engine forward. Unless the 3800 you are speaking of was in a minivan? Those are never easy.
My personal contribution would be my 94 camaro with the Lt1. When it had stock exhaust manifolds (they are above the plugs), AIR injection plumbing, they were pretty tough to get to. My first plug change it was obvious that the #8 plug (passenger side rear) had never been changed, due to the other 7 being a obviously newer AC Delco's. removing the starter and getting it from below the car was pretty much a requirement.
In contrast, now that the emission equipment is gone, has long tube headers, its about a 30-45 minute job.