Working through Volvo Penta D1-30 issue

[BrettB]

Seems like the coolant went past the pressure cap and into the bilge.

[BrettB]

Also have now tested the thermostat in a pot of boiling water and it seemed to open up just fine.

Unfortunately, it seems that professional help is hard to come by along the GIWW. Almost to Morgan City, will try there as well.

[Paul L]

I chased down an overheating issue for a friend with the same engine. It turned out to be a leaking freeze plug. You had to remove the air cleaner to see the leaking plug. Just FYI

[jamhass]

It certainly sounds like an overheat issue. Search this forum for many ideas. A quick way to verify overheat is to use as laser thermometer, available at most hardware and automotive stores.

Likely issues:

blocked inlet
blocked strainer
obstructed heat exchanger
obstructed oil cooler
ditto tranny cooler
bad thermostat
faulty coolant pump (the one pumping coolant, not raw water)
slipping fan belt
blocked mixing elbow
water pump">raw water pump -- is it actually turning? Volvo uses a plastic drive gear that can and does fail.
many other possibilities, some pretty subtle.

[OldGreyB]

See the link here https://j109.org/docs/volvo_d1-30_workshop_manual.pdf for the Volvo workshop manual. Page 24 shows the cooling system with the closed circuit freshwater and the seawater exchanger. Pages 90- 97 show all the system.

You have already stated you have checked the thermostat and sea water impeller. However as you also state “ the water has come past the pressure cap into the bilge” indicates an overheating event. You need to find the reason, before you do more damage, (such as blown head gasket, if not already).

Your “It seems like perhap the water outflow with the exhaust is not quite as constant as the other engine. More of in spurts of zero to medium amount vs the other engine that spurts between a little and a lot, but always at least something coming out.” Could indicate blockage in the seawater side of the cooling system. If you have low flow, then low heat exchange, hence higher temperature within the closed system. I would recheck all the seawater side and find out why the perceived lower flow. Check the exchanger core in particular. Page 93

Pages 97 show you how to access and check the closed system coolant pump.
Work your way methodically through each system, especially ensuring the heat exchanger is clean on the seawater side. The manual on page 91 gives you a good check list which is similar to Jamhass reply.

I agree with DougR, with respect to rational for battery alarm & that the relay issue is probably a red herring left from the PO. The wiring diagrams page 100 – 103 do not show any relay that is energized directly by the alternator voltage. As per your photo the #85 is the power to the coil. The #86 & #87 are looped to the negative, so whatever was wired to #30 was grounded when the alternator is running.

Take your time, be methodical. Refer to page 24 to understand how it all works. Once you have validated and hopefully found a blockage on the seawater side, refill the coolant system with fresh coolant. Run the motor for a few minutes with the expansion tank cap off. If you see bubbles forming and then frothing you may have damaged your head gasket. If so shutdown immediately and learn lots more or find a good mechanic. Youtube have video’s of what to look for. However if the over-temp or yourself have shut it down in time, then as long as you find the reason before running more, you could be fine. A wee caution the indicator of the motor not freely turning is a concern with respect to coolant water not where it should be.

Remember the Volvo marine engine is similar to Perkins tractor engines, so ask for a local tractor shop, as the local mechanic can probably help you once you have confirmed the seawater cooling circuit is working.

[BrettB]

Thanks for everyone's reply so far. We made it to Houma on one engine in hopes of getting more help in a larger town.

Also dove on the sail drive, nothing in the inlets or the prop.

I figured out I was pretty easily able to turn the water pump behind the belt. It looks like our mechanic in Kemah installed the wrong belt, as the alternator was adjusted out to the maximum tension and the water pump still turned. Considering this, I am surprised we made it as far as we did. Also noticed the hoses near the belt were nicked but it hasn't caused a problem yet(will replace them and get spares). Zip tied them back in the meantime.

We then found someone here in Houma to actually come by and take a look, not Volvo mechanic but finally someone willing to help. He said my belt tension was now good after my adjustment but diagnosed a blown head gasket. He also found that the bleed screw on top of the Rancor was stripped.

Called a Volvo Penta mechanic in New Orleans and fingers crossed, we are able to get them out here with the right parts in one trip, rather than two, considering it will be about $600 round trip for their drive alone.