Coolant Level Alarm

[adi999999999]

Hi,

I have recently fitted a coolant level alarm (Hayden) but it bleeps every now and again, the coolant level is fine, but about every 5-7 mins after start up for the first 30-40 mins of running the alarm momentarily sounds.

Has anyone any idea what may be causing this.

Thanks.

[g8dhe]

Has the coolant been added to or changed recently ? The coolants contain additives that deposit on metal surfaces to prevent corrosion, this includes the sensor screw and so it insulates the screw from contacting the coolant. When the engine is cool, don't release the cap, just remove the screw give it a wire brush to remove the coating and put it back in.

[Bob]

Welcome aboard.

Hayden will reply quickly to a phone call or e mail, but my first thoughts are a poor battery or newish 5 year coolant, it can coat the sensor screw.

[adi999999999]

Thanks for the replies, battery is new, but I have changed the coolant recently, so it might be that, I’ve cleaned the screw tonight so I’ll see if that solves the problem. Cheers

[haydn callow]

If it was the new coolant (red type) the alarm would be on constantly. You say it it beeps for a while after starting....the coolant level should be a inch above the sensor screw when engine cold....it could be the coolant is a bit low and it beeps when the coolant slops cornering. As it warms up it expands and the level rises....turned NG9, the alarm off. Humour me and add half a pint of water to the tank and report back.

[adi999999999]

Added a bit more coolant and al seemed ok, but now I have an issue with the Bongo loosing coolant over night, that I can't figure out, 2 days ago I started the bongo first thing and the coolant alarm has sounded, checked and coolant was low about 2 pints, checked and couldn't find any leaks, topped up and bled, drove all day no alarms and engine temp at 95-97 as normal. parked for the night checked coolant level all Ok, next morning same again, needed 2 pints to top up, can't find any leaks, topped up and bled ran all day, next day same thing, any ideas?

Thanks,

[g8dhe]

Possibly a pinhole leak, it squirts out under pressure and then overnight as it cools down it sucks air in and then the level goes down, if its a diesel be wary of driving it as eventually it will airlock, overheat and likely damage/crack the head. Try running it at night when its cooler and with a torch look out under the seats for a spray of steam or the other possibility is the water pump seals.

[Northern Bongolow]

Water pump is the usual suspect for leaks like this, it's hard to detect.look under the casting at the 6 o'clock position with a dentist angled head mirror you may see a clean coolant mark on the casting, it's not the hole at the 3 o'clock position looking from the front.

[adi999999999]

Found a leak coming from the bleed pipe where it pushes onto the engine, coolant was been evaporated on the exhaust shield, and also absorbed into the sound deadening under the passenger seat as this was saturated. The pipe had become very soft and had 4 or 5 tiny splits around the wider part of the connector, remade topped up and bled, fingers crossed.

[Bob]

Really useful update

Thanks