I'm hearing reports that the camshaft sensor gasket can leak and/or fail, resulting in anything from an odd smell to smoke in the engine compartment. If you have those symptoms, you may want to check to see if a leak has developed at the back of the valve cover, where the sensor attaches.

The problem, apparently, is that the o-ring gets dry from repeated heat cycles, and eventually fails. This allows oil to pass by, toward the rear of the block. A tired engine with lots of blowby can make it worse, as the increased pressure within the engine can give the oil more of a push past the failing gasket.

I've not verified this on my car, nor do I currently have pictures to share. If I do get around to it on my car, I'll post pictures and a description here.

If you're working on the top end, it may be a good idea to replace this seal. I know I will.