Mercruiser 3.6l diesel oil leak

[Converging]

Just found a really strange oil leak on my Mercruiser 3,6L diesel. It appears to be from the top pf the cylinder head, I cannot see where it is from but there is a very small capillary tube that runs aling the top of the head that looks suspicious.I cannot tell where this tube comes from or goes too. Any one had a similar problem of is this a red herring???

 

[gingie]

oil

the capilery tube runs to each of the separate heads as an oil feed follow it from the last head it has a swaged on pipe that run round to the starboard aft end of the block with a union fitting on the end. these pipes sometimes fracture.

most common on these engines is the rocker gasket. it leaks but looks clean but the oil flows elsewhere and traces around other components. we had 7 different material makes on rocker gaskets to try and stop the leaks. failing that is sometimes the big bolts that hold the rocker cover down sometimes work loose as well.

 

[Converging]

oil

Thanks Gingie thats real helpful. I had discounted the rocker gasket and will now take a closer look.
If it is the capilliary pipe, is it a big job to change it and any ideas were I might get a new one? Boats in Cardiff.