Temperature warning light flashing

[timjwharton]

Hi,

My temperature warning light came on during a run out today and began flashing. The temperature gauge was between zero and halfway. I stopped, checked the levels and everything looked normal. I started up again, took it gently the rest of the way and the light stayed off.

I've checked in the Wiki and it says:

'More often than not it is due to the level sensor in your header tank has become gunged up and is incorrectly thinking that your header tank is empty. Remove the two pronged sensor from the tank and give the prongs a clean.'

I'm not mechanical at all. Can anyone tell me what the sensor looks like and with what I should clean it (if I can find it, that is).

Thanks. It feels nice to be able to ask like-minded van fans these things. Great forum and great resource.

Tim

[AdrianC]

You've checked the levels... in both coolant tanks?

The level sensor's in the pressurised tank - the one with the blue Dalek cap. It's the only thing on the tank with a wire going to it. You can't miss it. Just give the prongs a good wipe off with a bit of kitchen roll. If there's anything particularly stubborn, a quick spray of brake cleaner or even WD40 will help it to wipe off.

[timjwharton]

Thanks Adrian. Yes, level fine in the tank inside the rear number plate, and the one in the engine bay with the 'Dalek' lid. Is it OK to remove that once the engine is cooled. You say it's pressurised. Coolant won't fly everywhere if I take it off?

[timjwharton]

And just to be on the safe side, what is the correct level for the coolant in the tank in the engine bay? If it's needs to be full to the brim, then I need to top it up (about 2/3 currently, which I'd assumed was OK).

[AdrianC]

And just to be on the safe side, what is the correct level for the coolant in the tank in the engine day? If it's needs to be full to the brim, then I need to top it up (about 2/3 currently, which I'd assumed was OK).

That's your problem, right there. And that coolant's gone somewhere...

Dalek cap should always be to the brim.
Catflap should be to the mark, just below the cap.

And, no, it won't spray everywhere once cool.

[timjwharton]

So top it up with water? And when you say it's gone somewhere, do you mean I have a leak somewhere?
Sorry to be so dumb.

[AdrianC]

So top it up with water?

Water/antifreeze mix, or premix coolant.

And when you say it's gone somewhere, do you mean I have a leak somewhere?

Yup...

Is it a petrol? If so, it could be leaking into the engine internally, because of a "head gasket" sealing problem. It's more likely to be an external leak from a hose clamp, though. Keep an eye on it...

[timjwharton]

OK, thanks. The hose coming from the tank was very loose (though no sign of any leakage there). I know what a head gasket is, and know I don't want any problems with that. Will keep an eye out.

[CJH]

It's more likely to be an external leak from a hose clamp, though. Keep an eye on it...

Yeah, they're buggers. If it's a hose clamp it'll probably only leak when the system is under pressure, so it might only create a fine mist. And since it'll be hot in the engine bay, and just about any leak from anywhere seems to drop down onto the exhaust, the leak will dry up quite quickly. Look out for tell-tale staining around the various hose clamps, in the colour of your coolant.

And don't rule out the level sensor itself (oh the irony!). It screws into the top of the pressure tank and seals with an O ring which may have lost its squishiness. Even if the coolant level isn't up around that seal when cold, it can expand up to that point when hot.

[AdrianC]

I know what a head gasket is

It was in quotes not because I didn't think you'd understand the term, but because the WBX doesn't really have a head gasket in the usual way - just the barrel seals.

[timjwharton]

Adrian - wasn't accusing you of being patronising, just remarking that I was heeding your warning.
I'm a Professor of Linguistics in my other life, and I think you 'heard' my sentence 'I know what a head gasket is' in a tone of voice I didn't intend... I certainly didn't mean 'I KNOW WHAT A BLOODY HEAD GASKET IS!'
Many thanks for your help. It's much appreciated!
Tim

[timjwharton]

@CJH - colour of coolant, rusty brown... I'm guessing that's not the way it should be?

[AdrianC]

@CJH - colour of coolant, rusty brown... I'm guessing that's not the way it should be?

Ewk. Definitely not. Time to drain, flush, and refill.

I'm guessing you've recently bought the van? I wonder what other routine maintenance has been ignored in the past... Brake fluid? Time for a very big service and thorough inspection, I think.

[CJH]

Ewk. Definitely not. Time to drain, flush, and refill.

This recent thread might be a good place to start.

[timjwharton]

Thanks CJH. Long story re the van. Bought her in 2003, lost her to my ex-wife in a divorce, have just got her back (the van, not the wife...) and spent a fortune restoring her bodywork to her former glory. Yup - full service here we come.