Dropped the boat in the water for the first time this season today. Started right up. (I love fuel injection) Oil pressure was at 40psi. Normally It will show 25-30 psi at idle. I idled out to open water and dropped the hammer. I noticed as soon as I passed 3500 rpm the oil pressure dropped and the needle bounced around at 20 psi. Up to 5200 RPM (40 psi is normal) and no change. As soon as I came back down to 3500 RPM the oil pressure went up to a solid 40psi. I turned right around and went back to the marina. The motor is a 2000 502MAG w/ 225 hrs. Is my oil pump about to go?
Thanks for your advise,

More than likely the sending unit is bad. You can check the gauge by disconnecting the sending unit wire from the gauge. Turn the key on it should peg the gauge in one direction. Then ground that terminal and should peg the gauge opposite direction. This would prove the gauge is not bad.

double check with a mechanical gauge.

Change the oil filter. May be clogged and when you push down on the stick it is going into by pass mode and that drops pressue to around 20#.

Yup.

All of the above plus a few. Check the terminal to the sender. They can get loose and give erratic readings at times. Second, check the ignition wires that run right by the sender. I just fixed the exact same sounding problem and it turned out to be a leaky ignition wire running by the pressure sender wire or the sender.

Check this thread out. http://www.offshoreonly.com/forums/s...d.php?t=156685

Hope it helps,

Rene

THANKS! for the help. I will check all of the above out this weekend.

PS: I'm Going to look really hard at the ignition wires....Did I mention I have a MSD ignition....

Any work done over the winter?

Only an oil & filter change.