low coolant level R-25 with D-3 Volvo

[portlandtug25]

Any thoughts/similar experiences from fellow D3 owners?
A couple weeks ago my 2015 D3 with 240 hours showed a "low coolant" message upon star-up. I checked the expansion tank and the coolant was easily visible in the neck of the tank,but I added one-half of a cup of genuine Volvo pre-mixed.started the engine anyway, and the warning message was gone. Took a 3 mile river trial, and the engine temp stayed normal.

Two weeks later we took an 8 hour round-trip hour cruise down the Columbia. Temp gauge was normal for the entire trip, over an RPM range of 1200-2500 rpm., but back home my slip the coolant warning came on on at the next start-up. Added another half cup coolant even though coolant was easily visible in the neck of the expansion tank. Warning went out. A River trial of 4 miles showed normal temp.

I see no signs of coolant in the bilge, no signs of contaminated engine oil.
Planning a San Juans trip in early September so I want to get this sorted out. Any ideas anyone?

Thanks!

 

[TBates]

Hello portlandtug25,

The Volvo coolant is used not only for keeping the engine cool, but also to warm the water inside of the hot water heater, and provide heat inside of the cabin through the heater below the helm seat. Both of these items could possibly have a small leak causing the engine coolant level to slowly decrease. The heater is easy to inspect by removing the four square head mounting screws, then inspecting the two black hoses/clamps on the backside. The hot water heater can be inspected by unscrewing it from the STBD cockpit locker floor, and moving it aft to inspect the hoses/clamps. When refilling the coolant reservoir, feel free to fill it all the way up to the top. There are also two black handled valves on the port side of the engine, which can be closed to prevent the coolant from leaving/returning to the engine. If the coolant level still drops with these valves closed, you'll know the leak is on the engine, not the other two items. If the level doesn't drop, you'll know it's leaking on either the hot water heater or cabin heater.

Thank you,

-Tim

 

[dclagett]

On my D3-150 I had a similar problem. It turned out to be a leak in the connection between the coolant supply hose from the engine to the heater/water heater supply hose. Look on the port side of the engine around where the oil dip stick is located. You will see two hoses connected with brass fittings. Feel the bottom of the fittings to determine if they are wet and sticky. If so this connection is leaking. On my boat these fittings are not pipe thread and require a washer which was missing. Whoever assembled the connection assumed is was pipe thread and only used pipe sealant, not the required washer. It is hard to get to these fittings in order to correct the problem. My bill from the yard that determined the problem and fixed it was $570. Look in my album there are pictures of the connection.

Hopefully the problem turns out to be one of the hose connections Tim described.

Good luck!

 

[portlandtug25]

Thanks Tim and Dreamchaser,

Furter inspection shows a slight sticky dampness on the stringer just below the brass fitting Dreamchaser describes. I have not had time to check hose fittings Tim described, but the leakage is so slight that I suspect that is the problem. it's that hard to reach fitting fitting.
The question is how to get to it, and if the washer is missing how to correct the problem..is it a DYI operation? Or do i need a Volvo mechanic?

And these questions for Tim: 1. My understanding was that I have 5 year warranty on the D3. The boat id 4 years old, so is this a warranty item? 2. If this is not fixed soon, is there a possibility of catastrophic loss of coolant? or will it just weep?

Thanks

 

[dclagett]

It sounds like the fittings or the hose connections to those fittings, around the oil dip stick, are the problem. I would look into it further to determine if the leak is between the fittings or one of the hose connections to a fitting. Completely dry the hoses that connect to the fittings and the fittings themselves. Run the boat and then carefully feel from each hose down to the connection to each fitting and between the fittings. Where you find coolant is where it is leaking. If you are lucky it may be a hose clamp to one of the fittings, otherwise if it is between the fittings it is a bigger problem. You will need to remove the fittings and determine the proper washer to install. This will require disassembly of some engine components to access the area. I chose to take it to a yard that I trusted.

If the leak is between the fittings you can continue to run the boat without concern of a significant coolant leak. That connection will not come apart. I believe that on my boat the problem started at the RT factory with using pipe sealant instead of a required washer. I continued to use the boat for a year after I discovered why I kept loosing coolant. I would need to add only a couple ounces every 10 hours.

Good luck... Dick

 

[TBates]

Hello,

As recommended by dclagett, the best first step would be to dry everything and run the boat to determine where exactly the leak is coming from. It could be as simple as tightening the hose clamps, as they can loosen a bit over time. Once all clamps are tight, you'll want to dry everything again and run the boat to verify no leaks are present. I'm not familiar with the fitting shown in dclagett's photo album. I personally commission each engine before it enters production, and every D3 I've done has a straight nipple installed, with no washer necessary. The 25SC might have required a 90 fitting, which could be why it's different. If you are able to send a picture to my email (listed below), I can verify which one your boat has. In the email, please also include your engine serial number and I can will check warrantee information.

Thank you,

-Tim