Coolant alarm going off on roundabout

[cobbdu1]

We’ve only had our Bongo for 6 months. One of the first things I did was fit a coolant alarm. Everything was fine all summer and now we don’t use the Bongo often. However, a few times recently the coolant alarm has gone off when I go round a roundabout, which I do within a minute of my journey. It doesn’t stay on and doesn’t come on again. I’ve checked the coolant and it seems fine.

Could it be because the coolant is cold and more viscous at the start of a journey? If not, what else could account for this or is it likely that I am actually losing coolant?

[Bob]

I suspect the battery is low.

Little use, cold weather, a single chirp just after starting.

Hopefuly someone more techie will have a thought, but I doubt it's serious.

[mikeonb4c]

When engine is cold the header tank level is lower. Mine started going off a bit when turning right just after setting off with a cold engine. I concluded the level might be a bit low and a right hand turn might move coolant away ftom immersing the sensor screw (albeit that the header tank is baffled) so I put a bit of 50/50 mix in and the problem stopped. Having said that, my LCA can murmur a bit esp when engine cold and can be persuaded to stop by for example dabbing the brakes. I think the voltage change caused for example by brake lights coming on can make it stop ( or is it a capacitance phenomenon. - who knows!)

[Flanners]

Top it up a bit, mine was grumbling a bit on tight cornering after a new cam belt/waterpump and coolant job, splash of coolant all good

[haydn callow]

Stick half a pint of coolant in... level is 3cm lower when cold compared to hot.

[nth]

I find when i start mine up from cold the test beep stays on for much longer, sometimes up to 5 seconds.
When the engine is warmed up it barely gives a single chirp.

[Bob]

Have you used the pink 5 year coolant?

If so it can coat the screw, just needs slacking off and cleaning with a wire brush.

[haydn callow]

I say again, stick a half pint of coolant in and report back.

[cobbdu1]

Okay, I’ll buy some coolant. That said, I’ve heard you need to be careful with this with regards to colour. The garage from which I bought the bongo insisted it must be green coolant so I’ll go along with that. However isn’t the norm to use red or blue?

[haydn callow]

If the coolant is fairly new just put a half pint of water in and report back. A bit of extra water won’t make hardly any difference.
Or
Dip the tank.....get a dry stick and dip the tank vertically, you should show about 1inch of wet stick after dipping. DO this when COLD.

[haydn callow]

Result of the above please !

[cobbdu1]

I dipped the tank. I put a stick in directly below the cap and it was just over 1cm depth. Suggests I need to add some more I think. I don’t know how old it is so I’ll buy some green coolant and add some.

[cobbdu1]

Is this the stuff:
https://www.commaoil.com/passenger-vehi ... s/view/563

[haydn callow]

1cm is Low Coolant . You need between 2 and 3 cms. The low coolant alarm was just telling you the coolant is low. Stick a mug of water in for now and then at some point get the coolant strength tested.
Remember that these alarms work and if they ‘chirp’ or go off, stop and investigate immediately. Delay at your peril.

[haydn callow]

Not much green coolant about these days which suggests it could be quite old or even put in there in Japan.....suggest you get a BONGO EXPERIENCED GARAGE TO ..DRAIN, FLUSH AND REFILL WITH BLUE COOLANT.......if you get red 5 year coolant put in expect the alarm to play up a bit for about a month, due to this type of coolant coating the internals and the sensor screw when coolant is new. If this happens remove and wire brush the sensor screw which will be in the front of the expansion tank......do this when cold with the cap fitted to prevent losing a bit of coolant.
DO NOT LET A LOCAL GARAGE WITH NO EXPERIENCE OF BONGO COOLING SYSTEMS DO THE FLUSH REFILL.