engine alarms

[johndezman]

my 1987 200hp has started indicating low coolant flow on both heads on the suzuki monitor and the audible alarm is sounding.<br /><br />i inspected the water flow from the top hose on each head and there was flow. i replaced the water pump impeller anyway to no avail. there is more flow from the top coolant return hose and there is visually the same amount of water coming from the exhaust (comparing it to the other motor (boat is powered by twins)<br /><br />the temperature on the block is such that i can leave my hand on the block without pain.<br /><br />essentially i feel this is a false alarm but what do i do to fix it?

 

[Bluefish]

Re: engine alarms

I'm not familiar whit your engine or set up but a general answer would be to check your sensors and connections. I also get a false warning horn on my omc, and have fond a shot of WD-40 in the ignition switch clears it right up must be a moisture problem for me.<br />Hope this helps

 

[johndezman]

Re: engine alarms

reread my post and i missed mentioning the brand- they're suzuki's. 87 vintage, twins mounted on a chris craft 313 center console with brackets.<br /><br />boat was originally salt water use, been fresh water the last 7 years. <br /><br />warning horn just started going off and the waterflow lights lit up on the suzuki monitor the last use, actually at the end of the last use. <br /><br />when i was trouble shooting last saturday, removed the sensors and with the ignition on, which lets the alarm sound, manually actuating the sensor had no effect on either the horn or the lights. will admit i didn't actuate both at the same time but since there is a light for each sensor the light didn't flicker either.<br /><br />don't know how much volume should be flowing but as i said in my first post, comparing both motors, the volume from the discharge is similar as is the time required to see flow at the tell tale on start up ie almost immediate.<br /><br />my ignition switches do not have easily removable "keys" ever since i had it they have not come out! some security!<br />any help greatly appreciated

 

[johndezman]

Re: engine alarms

guess i should restate the question. is it more probable that BOTH flow switches would fail simultaneously or the monitor has failed?

 

[Mike M2]

Re: engine alarms

Well, i can say this. Don't take the warning buzzer as malfunctioning unless you are 100% sure. I have a 200 merc here in the shop the buzzer went off, the owner thought it was water problems. he changed the impeller, stats, it still did it. He disconnected it thinking there was a malfunction with the buzzer, only to burn it up from lack of oil, which the buzzer covers also. Him being stupid is costing him 2 grand.

 

[johndezman]

Re: engine alarms

shop manual indicates two beeps from the horn then a 7 sec pause.<br /><br />this alarm is a beep with about a 2 sec pause.<br /><br />the dash gage has an indicator bulb for water flow to each head, both are illuminated. water flow from the telltale is strong as is the flow from the exhaust discharge.<br /><br />oil tank is just below 1/2 full, well above the low oil alarm point.

 

[clanton]

Re: engine alarms

Did you clean the floats, the last and only one I worked had alga and junk on the float, cleaned with toothbrush.

 

[jrbpit1]

Re: engine alarms

I had a similar problem on a Chrylser 75, I kept getting an overheat buzzer. I changed the impeller and thermostat and still got the buzzer. After posting this problem on this board, it was recommended that I do a compression check. Sure enough one cylinder had lower compression and the cause was a blown head gasket. The motor ran like a clock with the blown head gasket, started fine and idled well. Just my .02, but after my ordeal I would look at the head gasket.

 

[johndezman]

Re: engine alarms

i'm going to the marina this morning to bring it home for the winter. i'll check the compression again, but when i was inspecting water flow (described in my first post) i did not notice any pulsating vapor/steam coming from the top hose connections, which i would expect if it were a blown gasket.<br /><br />again, the monitor is indicating water flow (or lack of sufficient flow) to both heads and this began simultaneously on both heads! the probability of two head gaskets blowing at the same time is ....

 

[johndezman]

Re: engine alarms

brought the boat home for the winter.<br /><br />examining the powerhead, i noticed that the oil lines going from oil pump to intake manifold had some air bubbles in them so i guess i'll check the oil filter and pump.<br /><br />assuming this is the problem (not water flow) why would the idiot lights for water flow be lit and not the oil flow light?