I have 2 -D1 30s for 12 years (2008). No corroded O ring issues. 1300hrs. Its not cast iron, its cast aluminum
Our problem came from the inside bottom of the exhaust
manifold (between the two bottom studs)
JB waterweld epoxy
the appropriate 1"x 3/16" hole. Clean to bare metal 1st. I have 50 hrs since repair, removed elbow
, all looks good. Know another boat
that did this same epoxy
putty fix 6 years ago and no further problems.
I would suggest that anyone with this Volvo penta
D1 series to remove the exhaust
elbows (easy) and clean the inside lip of manifold epoxy with JB Weld to prevent this failure.
Only a 2 hour job, and I wish I had done this 12 yrs ago, at the same time inspect the exhaust elbow