2012 Mercruiser 4.3 MPI Guardian System Buzzer

rowen211

Cadet
Joined
Aug 10, 2010
Messages
10
Here's the story, the family and I packed up the Sea Ray 190 Sport and headed to the Florida Keys for a little vacation. The first day we had it in the water, we ran aground (anyone who knows the Keys will understand). Since that happened, the engine warning buzzer began sounding at pretty random intervals, forcing us to idle until it stopped. We discussed the problem with a couple of shops and the general consensus was that the thermostat was broken. We replaced it ourselves (every shop within a 2 hour distance is backed up at least 2 weeks) but the problem still exists. All fluid levels are ok and nothing seems excessively hot. At this point, we're stumped. Any help would be greatly appreciated.
 

500dollar744ti

Senior Chief Petty Officer
Joined
Jul 23, 2012
Messages
691
Are you loosing gear oil from the reservoir? If it drops to low it will buzz. The two likely causes from running aground are the water pump in the lower unit sucked up something and roached the impeller, causing an overheat, or you are loosing gear oil somewhere.
 

BIGALF1

Cadet
Joined
Jun 6, 2014
Messages
25
Did you backflush the water line yet? When I ran agroud in Ft Mtyers I had a lot of mud in the water line. It can easly clog up the hose between the outdrive and the engine.
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,268
Any chance at getting your serial number? Do you have a catalyst exhaust system or standard? Do you know if your thermostat housing has a poppet valve? It would look something like this if you do, http://www.mercruiserparts.com/Show...desc=Thermostat+and+Housing,+Standard+Cooling

Catalyst exhaust would look like this, http://www.mercruiserparts.com/Show...417&bnbr=170&bdesc=Exhaust+Manifold+and+Elbow


On the power steering cooler near the rear of the engine, you should see a sensor (item # 16 link next), If it were to be clogged it could set the engine into guardian mode. To remove the sensor, you would need a deep 1 inch socket or wrench if you have the room. To inspect the area you could remove the water hose closest to the sensor. Like others have mentioned, back flushing may help.
http://www.mercruiserparts.com/Show...inbr=12839&bnbr=280&bdesc=Steering+Components

....Hope you find it soon to save your vacation, good luck.:)
 
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