How I Fixed The Dreaded Volvo Fuel Pump Whine

[Dave Dup]

It took me half a summer to figure this out but since I have made the fix it has never been an issue since. What I found was the fuel reservoir cooling hose that discharges into a connection on the exhaust manifold was not flowing water when the boat was idling. I tried all the other suggestions and even bought a new pump but still had the same whiny problem. It wasn't until I disconnected the fuel cooling hose from the exhaust manifold and extended it outside the boat via a side mount thru-hull fitting did my I whining issues and overheated pump problems go away. Don't ask me why but for some reason when idling, the exhaust creates enough back pressure in the manifold to restrict the flow of water flowing from the fuel cooling hose. I'll try to send some pics of the fuel reservoir connections.

 

[Dave Dup]

No Title

Here is a pic of the back of my pump showing the fuel reservoir connections. the hoses are 3/8" ID. The bottom right of the pic shows the incoming raw water hose connected to the bottom of the reservoir. The top left shows the hose connection nipple for the cooling discharge line. This is the line I disconnected from the exhaust riser and extended out to a side thru-hull fitting. It's been over two years of trouble and worry free boating

 

[Dave-R]

Here's what I think is happening. If your water pump is not is not putting out enough flow, this could be the cause. I think I would make sure the pump is not worn out, or the wrong impeller used. An air leak on the suction side of the pump could also be the cause. Maybe even a line partially plugged. This to me makes more sense. Dave-R