Broken Alternator Belt = Warm Motor

[Weave]

Lost an alternator belt yesterday and thankfully I had my tools and a spare wrapped around the frame!!!!
My question is I was able to spot it after the motor got a little warm. It usually runs spot on 150F and this time it got to around 170 for a couple minutes. I shut down and fixed the belt, let her cool a little more and then fired back up and she went right back to normal op temp.

Did I do any damage? How would you guys have handled it?

 

[RiverRat]

Well, I think you handled it just fine... You had the spare parts and tools on hand and repaired the problem before any damage was done ( meaning that 170 degrees isn't hot enough to hurt anything)

Nice catch! :thumbsup:

 

[Weave]

Thanks RiverR,
Its a nice feeling when a plan comes together and all the "anal retentiveness" pays off! Often times folks think you may be going overboard on preventions, etc.
Yesterday payed of nicely!!!

Thanks for the insight :smt038

 

[comsnark]

Well. . .to put this in perspective: I don't know what engine system you have, but in a boat this size, I would expect an Alpha drive.

With an Alpha drive, you have a water pump in the drive and a raw water pump on the engine. My 5.7L has a single belt driving all accessories, including the alternator and Raw Water pump. If you loose the belt, you loose the Raw Water Pump. The engine will overheat and die without it.

And you caught it BEFORE the engine temperature alarm came in? That is indeed a good catch. :thumbsup:

Many boats RUN at 170F. (My boat runs at 170F on the gauge with 160F thermostats installed -> sounds like your boat has a 143F thermostat installed (perfectly normal to have that))

 

[Weave]

Comsnark.....It's the regular run o' the mill 3.0L with power steering. So yeah it has the Alpha

I contstantly scan my guages, temp, volts, , oil press......always worried about something!
Probably saved me the rest of the summer and some costly repairs for a few minutes of preventative maintenace.

Sorry for rambling on just counting my blessings........I might add that I was out boating ALONE when this happened

 

[Sea Ray 300]

Its a nice feeling when a plan comes together and all the "anal retentiveness" pays off!

I'd say you did everything just right.

Glad it worked out so successfully.

 

[First Born]

Nice catch sir!!!

Wesley

 

[MLauman]

(My boat runs at 170F on the gauge with 160F thermostats installed -> sounds like your boat has a 143F thermostat installed (perfectly normal to have that))

Same here - 170 per the guage.

Weave - I would have handled just as you did. In fact, I did just that about 3 weeks ago when I lost my water pump belt and had to make a field repair (in a thunderstorm, no less). But I didn't have to worry about shutting down as the same belt drives the fuel pump! Still, the temp edged up to 200 in the few seconds that it kept running.

170 is nothing - you're good to go.

 

[nben]

I've lost two belts in two years on my 3.0. Last time out I did not have a spare with me but caught it right off (no power steering when it goes). I found that if I went 1200 RPMS or so the raw water pump in the outdrive did a fine job of keeping the engine right around 170-175. I only had to go for 15 minutes or so as I had just left the dock. Made me extremely nervous though.

I absolutely HATE the belt set-up on the 3.0 Mercs. My buddies 3.0 Volvo has a serpentine set-up which is easier to change and lasts much longer. The Merc. set-up wouldn't be that bad if you didn't have to deal with that front motor mount. I have found that keeping the battery up when not using the boat with a battery tender/charger makes a difference. I check the belt tension before every outing and change the belt often!

 

[Weave]

Interesting that you had lost belts too...I have replaced then twice already.
A fellow on iboats.com said that it may be due to pitting on pulleys. I have a bit of pitting and was wondering the best way to get them off since I have a sand blaster at work!

 

[nben]

My pulleys have a slight amount of pitting but nothing compared to what I have seen on some of our equipment at work.

I went to change my belt last night after work and found what probably was causing my problem. The hub on the water pump shaft (pressed on at the factory that the pulley bolts to) had "walked" out on the shaft to the point that pulley was slightly rubbing on the motor mount. I pulled it apart and pressed it back where it needed to be, got it back together and tested it out on the muffs. Within 15 minutes it had slid right back against the motor mount. Not only was this causing a ton of drag on the pulley but also really messing up the belt alignment. I'm headed on vacation for a week starting Friday and didn't have time to find a new pump (9pm!) so I pressed it back again and welded the hub to the shaft. I didn't get it too hot and was careful not to cook the outside front seal. Long story short - problem solved!

Hopefully this stops some of my belt issues. I can't believe that I didn't catch this before. Maybe something to check on yours? The rubbing noise from the pully on the mount was only slightly audible with the motor cover off and undetectible with the cover on.