Narrowboat Problem... the engine won't start

Owning a narrow boat as a rule brings mainly, enjoyment and a lot of fun. But it also has its down side. Things can, and do go wrong from time to time, but with some knowledge and a bit of experience you can get over most problems yourself.

The Problem

One problem you may encounter is “The engine won’t start” so let’s look at this problem, highlight the possible causes, give you the solution and provide you with some knowledge so hopefully it doesn’t happen again in the future.

The Possible Causes 

1. The engine makes no attempt to turn over; it may be a faulty starter motor solenoid, starter motor or no electrical supply to the solenoid. The latter can be checked with a multimeter. If a click is heard from the starter motor, but it doesn’t engage with the flywheel it may be a faulty gear mechanism, similarly if the starter motor can be heard rotating but the engine doesn’t turn over. If the batteries are completely flat, it will show up on the battery condition monitor.

2. The engine turns over slowly but won’t fire; probably a low battery, confirm this by using a battery condition monitor. It could also be caused by general damp or a faulty alternator. Or lastly it could possibly be a discharged battery.

3. The engine turns over at normal speed but won’t fire; could be that the glow plugs are not energised for long enough or a failure of one or more of the glow plugs or their power supply, this can be checked with a multimeter.

4. It could also be a fuel problem; (no fuel, blocked filter, air lock in fuel system). The general opinion here is, if a diesel engine has a correctly timed fuel supply to the injectors and it’s heated by either the glow plugs or residual heat in the cylinders, it will fire.

The Solutions

First allow at least ten seconds for the diesel plugs to heat up before starting  in neutral with high revs.

For a damp engine use a dry cloth over any damp surfaces then spray area with WD-40. The recurring problem is more likely to be caused by a alternator, faulty leads, plugs etc. which may need replacing. Once started make sure the battery gets a full charge, leaving it to run, in gear and under load, until the battery condition monitor shows a full charge.

Check battery charge levels with a multimeter.

Clip your meter across the battery terminals and take an immediate reading. If the reading is more than 12 volts the battery is probably okay, but if it is less the battery may be undercharged.

If domestic batteries are discharged but starter battery is OK switch to starter and start engine. Then switch to "charge both" with engine running until batteries recover. If they do not recharge and hold their charge, replace ASAP.

If all batteries are discharged try to get a start from another boat by connecting their battery to yours with heavy duty jump start leads.

If mains supply is available use a mains battery starter.

How To Avoid In The Future

• Install a permanent battery level indicator and check this regularly.
• Always switch between starter battery and domestic batteries, charging both together but using the starter battery only for starting the engine.
• Keep the engine compartment dry and well vented.
• Clear the drains.
• Clear the bilges with a pump.
• Wipe out the engine compartment to limit condensation.
• Start the engine from time to time throughout the winter season and leave under load in gear for a while to recharge the batteries.