340 Monsoon question

[Deltawake]

We have a 2007 WS VLX with 1500+ hours on it. It has the 340 Monsoon engine. We have done the recommended service like clockwork. It has never gone more than 50 hours without an oil change etc.

My concern is that when the boat was newer, the oil pressure ran in the 56-58 range at wakeboard speed and under load. Now the boat runs with oil pressure in the 45-47 range. Occasionally, at idle, usually after coming off plane, we will get the low oil pressure warning. (beep and flashing message on dash) It always goes away after maybe 1-2 seconds. There is no perceptible loss of power, and we don't burn any oil. (maybe 1/2 qt. - 1 qt. in 50 hours)

My question is what is causing this? Is it possibly the oil pump going out? Is it just wear and tear on the seals, and they are just wearing out over time? At what point do you do a complete rebuild of an engine to prevent catastrophic damage to the engine/block? Is there something else I should consider?

[RTS]

I would start with the sensors, both of them. The one for the dash gauge and the one that feeds the ECM. Wouldn't be too much money and you can do it yourself.

It would be a very rare, almost unheard of, situation for the oil pump to fail.

I'd start with the sensors and go from there.

[thethrillofspeed]

What weight of oil do you run in it? Next oil change I would change to 20W50 and see if that helps and have an oil analysis on the old oil to see if it is getting contaminated.

[Kiwionsnow]

Good servicing has served you well. Before you buy sensors you need to install a manual oil pressure gauge on that same oil gallery and confirm the oil pressure when the beeper sounds.

If it is a sensor change it out and adjust the Viscosity up a tad and start planning a refresh in the 500 hrs.

The Culprit is likely Rod and Main Bearing wear along with Camshaft bushing wear along with oil pump wear. That would explain your overall lower running oil pressure vs new.

Your right a Pre-failure rebuild is much cheaper than sending a connecting rod out the side of the block and dealing with those additional costs.

If you do confirm a dropping oil pressure is activating the alarm and the sensor is good Most surface to surface wear should be consistent so something else is causing a pressure loss and then recovers. (oil pump relief). This can also been seen when a main bearing rotates in the block bore but usually results in certain failure very soon.

Step one first, Manual Oil pressure gauge!

[electricjohn]

Adding a tee fitting and a direct reading pressure gauge where the senders are will verify your pressure. Sometimes a low reading at the dash is caused by a bad connection in the cannon (engine room to helm) plug.

[jkendallmsce]

Adding a tee fitting and a direct reading pressure gauge where the senders are will verify your pressure. Sometimes a low reading at the dash is caused by a bad connection in the cannon (engine room to helm) plug.

ANd get a good gauge, 270 degree sweep.

Had to do the same on the previous boat. Between the hammerhead and all its problems and the digital gauges, the low oil pressure alarm would go off after even 30-35 mph runs. So I attached/installled a gauge to where the sensor was (just above the oil filter) to verify the oil pressure. The problem was both the hammerhead and the digital gauges....