Hi all, just joined and thought I would put this on that happened on my RR.
Was getting a slight tick and a rough idle, just noticeable but seemed to run fine ..
Then after a run down road pulled up at lights and it sounded terrible and rough.
On investigation found rocker shaft on lhd bank looking from front, had sheared where hole is for holding down bolt on rocker tower, it had been like this for a while judging by the state of the sheared surfaces, the engine had 110,000 miles on regular oil changes etc, luckily there was no other damage at all and new shafts are cheap enough, so I replaced both of them, all good now..