Mercruiser mpi alarm

[Aaronrux]

I have a 2004 Bayliner with mercruiser 5.0l mpi. I have a steady alarm that will go off sometimes. According to everything I have read and info I have gotten from dealers, since it is steady it is more than likely oil pressure or temp issue. Sounds straight forward but... I have replaced the raw water impeller, low water pressure switch and thermostat in the last several weeks. The temp always reads 168-170 with the highest I have ever seen it at was 175 one time. According to several shops that is fine. The oil pressure reading is within the normal of a small block. 45-50 at idle and 60ish running. The drive lube level is fine as well. I am at a loss on what to look at next. There is no pattern to the alarm, but when it trips, it will trip at 2200-2400 rpm and usually after I have ran the boat for a bit and shut it off. On restart and take off is when it trips. I have spent all summer trying to trouble shoot this. No idea any longer. Thanks for you help.

 

[Scott Danforth]

170-175 is a bit high.

In addition to water temp and oil pressure, you have water pressure and lube oil reservoir that may trigger the alarm.

Based on your higher temp, as well as the alarm. I eould be looking at water pressure. Could be a failty sender, could be sometging awry with your water flow

Is this a salt kept boat with a bravo drive? If so, google bravoitis

 

[Aaronrux]

Alpha one gen 2 drive. Fresh water boat. The temp normally runs in the 160s to 170. Temp gauge doesn't give me exact, only has a few numbers on it. It is consistently under the 175. The drive lube is fine. Plus the drive lube alarm is different, it is an intermittent alarm where this is a steady one.

 

[alldodge]

The drive lube is fine. Plus the drive lube alarm is different, it is an intermittent alarm where this is a steady one.

Sorry, but No, the drive lube alarm is also a constant alarm. The most often cause for the alarm is the water pressure sensor which is mounted on the power steering cooler

 

[Aaronrux]

Sorry, but No, the drive lube alarm is also a constant alarm. The most often cause for the alarm is the water pressure sensor which is mounted on the power steering cooler

I will check that water preusse sensor. I replaced one at the back of the motor already. The lube alarm on this IS an intermittent alarm. I changed the drive lube and started the boat as some air from the system makes it was up to the reservoir bottle it can trip that alarm and it did so got to hear that one first hand. It also states it in my shop manual and owners manual.

 

[alldodge]

The lube alarm on this IS an intermittent alarm

It also states it in my shop manual and owners manual.

I guess you have the only Mercruiser shop and owners manual in the world that shows that

If it is then its been replaced. To prove the point, disconnect both wires from the bottom of the bottle. Turn the key ON and connect the two wires together, not the ones coming from the bottle, the ones coming from the harness. Should be a Tan?Blue and Black wire

 

[Aaronrux]

I guess you have the only Mercruiser shop and owners manual in the world that shows that

If it is then its been replaced. To prove the point, disconnect both wires from the bottom of the bottle. Turn the key ON and connect the two wires together, not the ones coming from the bottle, the ones coming from the harness. Should be a Tan?Blue and Black wire

I will try that.. but as for the alarm there also a sticker right above the throttle that says the same thing. And again I have heard it. Not trying to be a jerk or anything. I appreciate any help. When this started that is where I started. Been working at this since June. I attached a screenshot of the owners manual. Also the drive lube level shouldn't put the motor into guardian mode at least according to everything I have found.