Hello everyone! I have a 2000 F-150 4.2L I'm working on. It runs very rough and shakes violently. It's throwing missfire codes for cylinders 1, 2, and 3. When I crank it up for a minute the passenger side exhaust manifold remains relatively cool compared to the driver's side, but it's getting spark to all cylinders. I popped off the intake and removed the passenger side valve cover, and there is one really crunchy looking valve spring in the back that looks to be on the verge of snapping. I guess my question is, would a single broken valve spring cause that entire side of the engine to missfire? Thanks!