First Jordan checked the gauge and the sending unit where he noticed when he took it out that a gooey gelled oil slowly seeped out. Unfortunately, the motor oil was completely gelled. Jordan had never seen anything like this. It was a nightmare.
What a messy job!
After taking the engine apart, Jordan took the heat exchanger and the head to a mechanic in town, where things were tested and passed, and the head got a quick reconditioning even though it didn't need it. However, there was no clear evidence that defined the problem. So Jordan is assuming that it must have been a one-time event/problem of getting seawater into the engine during our last passage from following seas that back-surged water into the engine through the exhaust pipe.
We have a water lock muffler and a loop in the exhaust, but when the boat is tipped repeatedly and with any kind of water back pressure, it is possible that there would be ingress of seawater. We have a shut-off valve in the exhaust for such conditions but had forgotten to shut it for a day.
So important note to self (and to other sailors):
When engine is not running, shut off the exhaust even when at anchor because the rocking may even pump water back.
Only time will tell for sure if we are right in the assumption of the problem as we make our way to the Marquesas tomorrow. If the problem reoccurs, then we will have to sail the remaining distance without turning on the engine. Oh well, that's what a sailboat is for, isn't it? Will let you know what happens when we arrive at the Marquesas...