So.... second time it's done this. The foot that rides on the camshaft has broken off the rocker arm. This is what killed it 5 years ago when I stopped driving it. Now... it did it again. #1 intake valve this time... can't remember what it was last time. I replaced all eight of the rocker arms with brand new dealer ones last time. Just swapped in one of the old ones this morning... but why??? I've never heard of these breaking before. I keep it below about 3500rpm -- usually more like 2500 to 3000, but sometimes 3500 when shifting.