Overspeed Warning and Oil Pressure Drop

[mmathma]

I have a 2004 Mercruiser 5.0 MPI that developed the following issue: I get an over speed alarm at 2800-3200 rpms and an oil pressure drop. When I throttle back oil pressure goes back up to normal. Please advise. Thanks.

 

[JustJason]

Re: Overspeed Warning and Oil Pressure Drop

check your oil level while the boat is in the water to make sure its not to high.

 

[mmathma]

Re: Overspeed Warning and Oil Pressure Drop

Normal Pressure is at 50 PSI, then drops to 20 PSI and overspeed alarm goes off. This happens when the boat is on plane.

 

[Don S]

Re: Overspeed Warning and Oil Pressure Drop

How do you know it's an overspeed alarm, and not an oil pressure alarm. Do you have smartcraft gauges? If so, which one.

 

[mmathma]

Re: Overspeed Warning and Oil Pressure Drop

It is a smartcraft gauge system. It does say overspeed when the alarm goes off.

 

[Fun Times]

Re: Overspeed Warning and Oil Pressure Drop

Have you done anything new or different to the boat or engine before this problem started, The first few things to check out as a starting point would be make sure all the ground wires you can find anyware on the engine and boat is clean and tight, Then try to make sure all the sensors on the engine it's self is pluged in tight and the wires are not damaged. And like JustJason said, Check your oil level while the boat is in the water to make sure its not to high.

 

[mmathma]

Re: Overspeed Warning and Oil Pressure Drop

I re-looked at my oil level and it appears that it is over filled. I have not added any oil, how could it be suddenly overfilled? It does not appear milky as to have water in it.

 

[JustJason]

Re: Overspeed Warning and Oil Pressure Drop

1. Does the oil smell like gas???

2. Was the last oil change performed on a trailer... or on the water?

Its common for oil thats changed on the trailer to come back over or under filled when the boat is on the water because the oil level needs to be checked when the engine is level on the water, not on the trailer.

 

[mmathma]

Re: Overspeed Warning and Oil Pressure Drop

I did remove some oil. Went out and ran it across the lake (varying RPMs) about 10 minutes everything seemed OK. Then all of a sudden I got a fault code of oil pressure sending unit and oil pressure started fluctuating, and then a hard fault of low oil pressure. Shut off and restarted oil pressure OK, then slowly dropped got oil pressure sending unit fault again and fluctuating oil pressure then got hard fault of low oil pressure. Shut down restarted and made it home (7 minute trip) with normal oil pressure at cruising speed. Would this be the oil pressure sensor/sending going bad? Or a wire loose? Where is it located on the engine? Thanks.

 

[havasuboatman]

Re: Overspeed Warning and Oil Pressure Drop

When was your last oil change? How over full was the oil? Did it reek of gas? If your oil is badly diluted with gas, that may be part of the problem.

 

[mmathma]

Re: Overspeed Warning and Oil Pressure Drop

Oil was changed last fall. It was over about a quart. It did not reek of gas.

 

[mmathma]

Re: Overspeed Warning and Oil Pressure Drop

Fixed it with a new Oil Pressure sensor.