Both top of my list now.
From the manual:
I’ve got 70 psi at idle.
I’m pushing nearly 80 psi at 2k RPM.
Something seems wrong… I’d question the accuracy of the gauges if there wasn’t two of them.
Agreed. Unless there was something that happened to both engines. 30 years with only 400hrs on the meter means they probably sat for years without use. So one theory is this is what happens when an engine “dries out”.
Have you gotten involved in the Bayliner forums? They seem to have a number of Hino discussions.
Yeah I’m a member of some of these pleasure boating communities. There are smart folks there don’t get me wrong… but you guys are the mechanics community. Hino… Cummins… Caterpillar… Dodge… All the knowledge will be consolidated here.
There are some things more appropriate for a boating community such as cooling systems. Cooling on the marine side is completely different. I once had a sailboat that was designed to pump salt water through the engine block instead of coolant.
Even though they both show high, I’d confirm the oil pressures with a known good gauge. Both gauges have been through the same wear and tear, both could be misreading the pressure. I don’t know how an engine at idle could generate such high oil pressures, at least a gas engine. The bypass valves usually kick in at high rpms.
And possibly a pair of incorrect sending units have been installed
Why are people ignoring the simple fact that oil is being blown into the turbos?
Incorrect oil sending units wouldn’t cause that.
Tester
When we ran out of fuel on the road we always restarted them with a can of starting fluid (ether). Some of our city trucks with the little 555 cube Cummins V8s didn’t use glow plugs, they had ether injectors. If you did a thumb dance on the injector button you coud pass another driver in a similar truck. If you got back to your home terminal before another driver it would be possible that you would be the last driver out that night and the second driver would lose a nights work. Even though all the freight companies in a local had the same contract each company had their own work rules. The last company I worked for we worked a wheel that was reset every Sunday by senority, but during the week it was first in , first out.
Given that the turbo oil return line isn’t restricted it’s likely the seals on the turbo have gone bad. I’m working with a local company to try and source the parts for the turbo rebuild.
How did two turbos fail on two different engines? Kind of wild. How do you get two failures simultaneously on two independent systems. Maybe sitting idle did a number on them. The only other way I can imagine is if the high oil pressure took them out.
That’s actually a pretty good theory right? High oil pressure restricts oil flow. The bearings aren’t being lubricated. The turbos failed when they ran dry of oil.
Mystery solved. Or is it? I need to find out for sure if the oil pressure really is through the roof:
Agreed. I’m going to check if an auto shop will rent out an oil pressure test kit.
IF the oil pressure reading is already accurate… then the next mystery is how did the oil pressure become so high… but one thing at a time. First let me find out what’s going on.
Turbo’s are really high speed compressors forcing air into the cylinders so they explode creating increase power. Their are exhaust powered ones and now electric motor powered ones, your are the old school one which are exhaust powered ones they are lubed & cooled by oil via coolers. The problem is that they do not last a long time, usually bearing with go out because of the seals going out first. When that happens smoke is usually the first sign its out or going out. The new Trucks big rigs if the seals goes out not only do they have to replace the Turbos but have the new smoke filters professionally cleaned usually costing an extra $400-$600 extra. If you can keep track of the mileage of the vehicle you can predict approx. when it will go out and plan of an R & R turbo replacement.
I use to work for a Big Rig Truck company retired now but still keep up with technology. I remember my first experience was on a D2 CAT Tractor it used a small gas engine to start the big diesel which was not injection technology,.no smog only a small muffler on the straight pipe which did not quiet the engine. It took a lot of maintenace. Very strong Engine.
Made it out to the marina to poke around a little more. I picked up an analog oil pressure gauge, attached it to the port engine, fired it up and let it warm up. Reset the gauge and… reads 40 psi! So the engines are not slowly grinding themselves to dust.
It’s worth noting that the manual says I should only have 7 psi of “standard oil pressure” but that seems… ridiculous?
I recently found out that marine engines with equivalent output to these cost $70,000 so that’s… good.
I’m really happy to report that you guys were right about oil pressure sensor being defective. It appears to be original since it’s covered with the same engine paint as the rest of the block. What’s crazy is that both oil pressure sensors failed on both engines in the same way…
It still smokes.
Recap:
I’ve got a local company helping source parts for a turbo rebuild. I’m guessing it will be about $1,500 for each turbo 
Removing the turbos to inspect them could give me some insights on the exhaust side.
I would speculate that if there’s wet oil in the exhaust side then the source of that must be the turbo seals. Because even if the valve guides, oil rings, or anything behind exhaust manifold leaked the combustion would burn the oil to smoke and there would be no oil pooled in the exhaust. Does that sound right?
