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Hello all, there’s a squeal from the engine when I start up and rev it. Battery lights come on dashboard until squeal goes. Ok once running for a bit.  Is it the belt too loose to the alternator or is my water pump about to go on the blink? Not very good with engines yet, I need to go on a course :blush:

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3 minutes ago, Tuttifruity said:

Hello all, there’s a squeal from the engine when I start up and rev it. Battery lights come on dashboard until squeal goes. Ok once running for a bit.  Is it the belt too loose to the alternator or is my water pump about to go on the blink? Not very good with engines yet, I need to go on a course :blush:

It sounds like the alternator belt to me. Check condition and tension.

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Sounds like belt slip.  It may be slipping because it is a bit loose or the water pump which is possibly driven by the same belt is getting a bit tight, it may also be that with this cold weather the belt is wet with condensation and the water is causing the belt to slip.

First off I would check the belt tension and some belt spray may reduce the slip if condensation is part of the problem.

Something like this  https://www.toolstation.com/shop/p25485

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Certainly sounds like alternator belt slip, belt worn or needs adjusting. If you want to check the water pump, either slacken the belt right off or remove it from the pump pulley, The pump pulley should turn by hand with a bit of stiffness, rock the pulley about by hand to see if there's any sideways slack in it.  A quick way to check if it is belt slip is to, directly when you start the engine up, squirt or flick a drop of water onto the belt, the squeal will cease immediately if its belt slip and then return as the water dries.

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It is going to be the alternator belt, if you have two alternators the domestic one.  I had A squeal on start from cold and I though the domestic belt was tight enough, and I was starting to think if was bearing related until I realised the it did not squeal when the engine was started from cold in the marina.  The difference being that when in the marina and on shoreline the batteries were fully charged when starting up from old, unlike when out and the domestic batteries were not fully charged. Tightening the domestic belt by a very small amount and the squeal stoped and has been fine for over two years.

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Thanks for all the comments, we’ll have a fiddle with the belt but hadn’t thought of the batteries putting too much load initially. As you know we’ve been stuck at sawley and cranfleet locks for 3 weeks and have been putting the engine on to charge the batteries for 2 hours a day, but as we’re bored stiff have had the telly on a lot, so the batteries are down to 11.7 every morning when we get up! 

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8 minutes ago, Tuttifruity said:

Thanks for all the comments, we’ll have a fiddle with the belt but hadn’t thought of the batteries putting too much load initially. As you know we’ve been stuck at sawley and cranfleet locks for 3 weeks and have been putting the engine on to charge the batteries for 2 hours a day, but as we’re bored stiff have had the telly on a lot, so the batteries are down to 11.7 every morning when we get up! 

:o Flippin eck. ou will probably be using nearer 4/6 hours per days charging worth depending on your set up and useage. You deffo need about 8 hours tomorrow then take it from there.

Have you any monitoring stuff?

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I doubt "chugging away" is enough. It needs to be revved until the domestic charging current (amps) stops rising an t hen left of 15 minutes or so. Have another look and if the ammeter has fallen decrease the revs a little until the charge (amps) drops then gently rev it until the charge stops rising. Repeat every 15 minutes or so.

You are likely to find you starst at 1500 rpm + and then over two or three hours you drop the speed to tickover but I would then run at a speed that produces minimum vibration.

As advise unless the batteries are shot you will probably need well over 8 hours charging. Keep charging until the charging current is about 1 to 2% of the battery capacity so for 220Ah worth of batteries keep charging until the  current drops to between 2 and 4 amps. This is a rough rule of thumb to ensure you keep the batteries well charged which will help extend their life. You can get clamp type multi meters that measure DC amps for around £30.

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If that was when you got up, in the dark, with the engine and any other chargers off and after charging them yesterday that is indeed good news. Thanks for the feedback.

If it was 12.7 with the engine or other charger running then its bad news. A CHARGING voltage of 12.7 volts means the batteries are still very flat, the alternator is faulty, the batteries have an internal short or you have not revved the engine enough.

The greater the amps the batteries try to take from any likely charging source the lower the voltage so an alternator that will charge at (say) 14.4volts several hours after charging starts will charge at a far lower voltage than that when charging starts. I feel 12.7V with the engine revving at the start of the day is rather lower than I would normally expect but with a very high charging current it could be right. I would typically expect on a reasonably specified system to get over 13 volts when starting charging.

 

On another related point. It can be difficult during the winter for non-retired live-a-boards to fully recharge their batteries every day although that is the best way of maximising battery life so many charge as long as they can each day and the make sure a very long charge is done each weekend.

You seem to have an ammeter and voltmeter so recharge as I described above and try to recharge every day. If you can not do that check the battery voltage when you get up (in the dark in case you have solar charging) and make sure you recharge ASAP if the voltage with nothing running gets down to 12.3 volts.

 

 

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Hi Tony, yes the reading was 12.7 in the morning when no charger had been on all night. When the engine initially starts the charge reads 13.3 or thereabouts and then gets quickly up to 14.3 for the duration so looking good. We now leave the engine on for 4 hours a day and follow your previous advice so thanks again. 

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