So I decided to pull the valve covers off the D2 to replace the gaskets. I noticed that all the rocker arms are in the same position except cylinder #6. It has one spring that is slightly compressed and the arm is about 1/4" down compared to the rest of them. Is this unusual? It hasn't been run in about two weeks. B.t.w. it does have a tick that I think comes from that side when it warms up.

Thanks guys

 

Not for an engine with hydraulic lifters once the oil drains out from not running in some time. You may also have one ore more lifters that don't pump up enough causing a tick.

What weight oil are you using?
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I'm running Rotella T5. Shouldn't that one rocker's lifter drain back so there is no compression on the spring?

 

10w-30 or 15w-40? Some LR ticking issues are helped by using a heavier oil.

The lifters don't disappear when fully compressed and still provide push rod lift. Not all lifters leak down at the same rate. One of the valve train gurus may have more specifics on your #6 cylinder valve if you provide the piston's cycle/position.
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15w-40. Question is that they should all drain down right?

Cylinder #8 is DTC