Broke a belt and overheated...now what??

[MC1600]

Ah, what a beautiful 75 degree day it was here in NC yesterday. Beautiful until the battery alarm, then overheating alarm, then "shut down engine" alarms all came to life in about 3 seconds.

The short of the long is that my serp belt frayed and came off the rollers. I was able to get it back on long enough to limp back to the slip.

Now obviously I will be replacing the serp belt, but is there anything else I need to check?? Could that momentary overheating cause any other damage I should check??

Once I got the serp belt back on, everything returned to normal, and she ran fine (at about 600rpm) back to the slip. I just want to know if I may have fried anything else that I need to check before going out again.

Thanks guys!!

 

[Morpheus]

I'm not an expert but this is my educated thought on the subject. I would hope and expect those alarms are in place to sound before damage occurs if you had ignored the alarms yes damange surely could be done. I had one of my idler wheels freeze and come off but I heard the clank/bang and shut down before any alarms.

So I'm gonna say your a smart boater and shutdown as soon as you heard the alarms and are probably find with just replacing the belt.

 

[Dave S]

That's a question better answered by your dealer or a certified Merc Mechanic but I can offer my thoughts on the matter. When the alarm went off, did you immediately throttle back the engine? Or maybe the ECM (electronic control module) cut off the fuel supply and throttled back for you. I mention the ECM only because I am not sure what it does when it senses a high temperature condition. Obviously your water pumps were not working (fresh water and recirculating) after the belt broke. So if you turned off the engine right away when the alarm was triggered, then in all likelihood you didn't damage the engine at all. However, I am not so sure about your (rubber) exhaust hoses comming off the riser elbows. Fresh water is circulated thru them to keep the exhaust temperatures under control. They might have some damage on the insides from the hot exhaust gasses but I think a technician could give you a better assesment on that.

 

[MC1600]

It was as I started to get up on plane - a VERY loud alarm went off, and the display on my dash read "check battery", "overheat", "throttle down", then "check engine" in about 3 seconds. As soon as the alarm went off, I shut-down immediately, so I think at this point, I'm going to see what happens once I get the new belt on, and go from there (see a tech if necessary).

The engine ran fine, though, at the very low rpm on the way back to the slip, and all the temp and instrument gauges returned to normal.

Thanks!

 

[fwebster]

As long as the engine stayed under 212 degreess F, nothing bad hapened.

When you get one of those crazy "check engine" alarms, scan the oil pressure and engine temp before shutting down so you at least know which end of the engine to start looking at for the cause.

 

[MC1600]

As long as the engine stayed under 212 degreess F, nothing bad hapened.

When you get one of those crazy "check engine" alarms, scan the oil pressure and engine temp before shutting down so you at least know which end of the engine to start looking at for the cause.

Thanks, Frank. Since I shut-down as soon as the alarms went off, I suspect you and the other guys are correct that the alarm would be designed to go off well before anything catastrophic happened. After I fixed the belt and started-up again, the engine temp was only at 159, so I think I was ok. Probably a good thing I shut-down as quick as I did. Lesson learned!

 

[Nehalennia]

I think that you caught it early and you are just fine. Check your oil and make sure there are no signs of milky Hot Chocolate( evidence of water from an overheated or blown head gasket) and if all is clear and like you said all is well and normal on your gauges, you should be just fine. My Guess is that the temp alarm (I recall set for 200 ~below Frank's stated 212) was well below failure or damage temp. Car and Truck thermostats are typically 180 or 190 and run water/coolant through your system at 190-195, (smaller volume of water to circulate and quick to recover) whereas the Marine engines run with 160-170 thermometers primarily to keep any raw Saltwater systems from crystalizing promoting more corrosion. In the normal range the lower temps keep the salt emmulsifying and ciculating as to not crystalize as easy or build up.

Sorry for the long winded answer, but I think you're fine.

 

[top*prop]

the bad thing about water temp alarms is that they olny read water temp. if there is no water in the thermostat housing for it to read then it will not go off. but i can say from what you are telling us, i can almost gaurantee you havent hurt anything, but i would check allyour exahust hoses, bellows and shift cables, anything that is located near the exhaust manifolds or y pipe. and check bellows in the transom assembly. i have seen people run there engines untill they lock up, let tehm cool off, run them again til they lock up and still not hurt anything.