[JFP in PA]

Originally Posted by 69911e

Will a degrading IMS always (or almost always) show a deviation in cam timing?

From Pelican Tech article:
"You can compare the deviations in the timing between the two camshafts to see if they vary widely, particularly when revving the engine (see Figure 18). Sometimes a failing IMS bearing will also trigger a “check engine light” warning on your dash, as the car's computer realizes that there is a significant deviation between the two camshaft readings."

Thanks
Ed

Not always. Many times, the IMS fails catastrophically and totally without any warning.