OK- This is long. 1993 Merc 150 XRi. Fuel-injected, oil-injected. I got the constant beep, beep, beep alarm last year on the second last outing of the year. I had been running on the river and had shut down to fish a hole. I fired up 1 hour later and went 50 yards and the alarm started beeping. I shut down right away and checked the oil reservoir. It was full. I checked the remote oil tank under my console- ¾ full. No leaks seen, no kinked hoses, etc. <br /><br /><br />I had already replaced the remote 2 ½ gallon tank due to a crack. I had also replaced the engine oil tank cap/sensor assembly because it was also cracked. I had pressure in the remote tank when I unscrewed the cap. <br /><br /><br />I restarted the engine after verifying oil. The alarm started beeping immediately after start up. I idled about 50 yard checking the run and shut off again. I once again checked things and turned the key on. I got the 2 beep tone and then started the engine. Constant beep, beep, beep right away. The water alarm L.E.D. was not lit so I knew it wasnt water in the fuel. It had to be an oil issue. <br /><br /><br />I brought it home and checked lines, etc. I found nothing odd. I did change the water separating filter because I had one sitting on the shelf. I ran the engine on a small tank of premix until it warmed and checked things again. No alarms, no issues. OK, must have been an air bubble or something. I guessed it was OK. <br /><br /><br />Went out two days later and ran the boat through the no wake zone and 2 miles upriver. The engine ran great and sounded normal and I got no alarms. I pulled up to our spot and shut down. We fished that area with several starts and stops and then tried to head out to another area. I fired up and the alarm started again. Constant beep, beep, beep. Now Im peeved because I found no reason for the alarm. All I could think was sensor failure or gear failure. This was the last outing of the year and I put the boat away for the winter. <br /><br /><br />Its now in my driveway and I just finished troubleshooting it. I did a few things before messing with the oil system. Water pump, lower unit and new thermostats. The heads were clean as a pin inside and I saw no issues there. Then I started on the oil system. <br /><br /><br />I checked lines again and found no problems. The tanks are good, as are the caps. I pulled the white wire connector from the module to the pump motion sensor and got 12.5 volts with the key on. I then reconnected the white wire and probed the blue/white tracer wire as directed. I rotated the engine by hand as directed and saw voltage go from 0 to 5.2V every two turns of the engine. However, I also got a weird out of range reading at one point like I lost continuity or something. It did it once and didnt do it again. From then on, it read 5.2V every two turns like normal. I have not yet done a pump output test as I believe the pump must be turning to give me the 5.2V reading from the sensor. I think the motion sensor is bad and should be replaced. <br /><br /><br />I ran the engine on a small tank of premix again in the driveway and got no alarms. The thermostats opened properly and I had good water flow. The engine sounds great with no odd noises and what seems to me to be the proper amount of smoke. I am going to try a motion sensor and see where that gets me. If that doesnt do it, its premix time. LOL<br /><br /><br />Does that sound like Im missing anything? I run Pennzoil synthetic and have since I got the boat two years ago.<br /><br /><br />UFM82
<br /><br />UFM82