BadAttitude

My dealer claims that the high temp alarm in all I/O's is useless, since they all depend on water flow to activate the temperature sender. Why is this different than an auto engine? Does no one use a positive flow alarm to signal a bad impeller or clogged water intake?

Carl

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Life is short.....Eat dessert first!

Yankee HI-TECH Redneck, 2001 Four Winns 260, 8.1 liter

tidester

I spit a belt once, beating tracks from the leading edge of a t'storm. No water flow from the engine circulation pump. Temp gauge pegged rapidly, so I knew it was time to stop and check it out. If I had rigged a temperature switch / alarm circuit, the warning horn would have definitely let me know - that motor got hot quick! Fortunately, we caught the problem in time to get the belt back on and get back to safe harbor before microbursts and lightning were around us.

Does a temperature gauge warn you of pressure loss? Not directly, however pressure loss creates heat build up, which a warning horn will tell you about very quickly.

MarkT

My Mercruiser Bravo III's actually have a low water pressure alarm (two short beeps every minute) and a high temperature alarm (steady beep). Two weeks ago I started getting a low water pressure alarm on my starboard engine. About a half hour later as soon as the temperature starting rising above 200 degrees it went steady.

I would like to think that I would have caught the rise in temperature without the alarms but the alarms made sure I didn't overlook the gauges for too long. Got home OK on one engine and the alarms and my actions saved the engine from a failed impeller.

If the temperature gauge started droping then I would have been concerned about no water flow. But since the impeller failed over a period of time the water temperature started to rise and it was clear I had a cooling problem.

The alarms are definately not useless. They are analogous to "idiot lights" but without them there is a better chance that you might overlook a serious problem and not take remedial action before it's too late.

MarkT