Audio warning system

[Shane]

I pulled all 5 drain plugs to let all water out to winterize my boat. I did not put any antifreeze in it. Yesterday I put the muffs on the boat and cranked it and the alarm wouldn’t shut off. I only ran it for 2-3 minutes but it never shut off. My understanding is this goes off due to low oil pressure or motor over heating. Could this be going off because there is not enough water in the system? Or is it more than likely my oil pump?

[mmwjr]

Welcome aboard!

What year and model is the engine? The carburetor engines have 3 sensors; low oil pressure, water temp, and gear lube reservoir level. The gear lube is a common alarm due to the reservoir level being too low.

[Shane]

Originally Posted by mmwjr

Welcome aboard!

What year and model is the engine? The carburetor engines have 3 sensors; low oil pressure, water temp, and gear lube reservoir level. The gear lube is a common alarm due to the reservoir level being too low.

It is a 2005 mercruiser 5.0

[Shane]

Mercruiser 5.0 2005

[mmwjr]

Originally Posted by Shane

Mercruiser 5.0 2005

Carb or fuel injection?

[Shane]

Carburetor

[mmwjr]

I would start with the gear lube reservoir level. Is it at the full mark?

[mmwjr]

You can isolate between the 3 by disconnecting 1 sensor at a time. Tan/blue wire on each.

[Shane]

Thank you

[Phillbo]

Originally Posted by mmwjr

I would start with the gear lube reservoir level. Is it at the full mark?

Good place to start...

[shrew]

In the late 90's model (In understand this is a 2005), the gear lube reservoir was 2 quick beeps, not a solid tone. Solid tone could also be overheating, but that would be almost impossible at start-up.

Check oil levels to see if you are OVER the full line. That might be an indication of water in the oil. Water will not circulate in the dipstick tube, so don't expect to see the 'coffee with cream' color on the dipstick.

[mmwjr]

Originally Posted by shrew

In the late 90's model (In understand this is a 2005), the gear lube reservoir was 2 quick beeps, not a solid tone. Solid tone could also be overheating, but that would be almost impossible at start-up.

Check oil levels to see if you are OVER the full line. That might be an indication of water in the oil. Water will not circulate in the dipstick tube, so don't expect to see the 'coffee with cream' color on the dipstick.

Shrew I’m pretty sure the multi-tone alarm is only on EFI engines and that carburetor engines that all 3 sensors ORed together and only produce a continuous tone.

[Shane]

If I drained all the water then there should not be any water in the oil, correct? Assuming I did it correctly. I pulled all 5 blue plugs but I did not put any antifreeze in it?

[mmwjr]

Originally Posted by Shane

If I drained all the water then there should not be any water in the oil, correct? Assuming I did it correctly. I pulled all 5 blue plugs but I did not put any antifreeze in it?

There should never be water in the oil. Typically if an engine freezes from not being drain properly the outer water jacket splits near the freeze plugs. When you removed the blue plugs did water come out? Sometimes they get blocked from rust and you need to insert a small screwdriver and wiggle it around.

[Shane]

Yes. Several gallons drained out. Yes I understand water should never be in the oil. Oil levels were good when I checked them. I just thought that since I drained all the water out that maybe the thermostat may be stuck and causing the alarm. Temp gauge was reading fine. I did not look at oil pressure gauge. Like I said I only let it run for maybe two minutes because I did not want to risk any damage.

[mmwjr]

Two minutes is not enough time for an engine to over heat. Did you check the gear lube level?

[Shane]

It was a little low. I’m going to add to it and try it again when the weather gets better

[Shane]

Gear oil was in operational range but added to full line and also lower the trim where it was not trimmed all the way up and alarm is no longer sounding. Thank y’all for all the help.