Just a reminder to check those coolant hoses! - update

[Roydini]

Hi Emma,

It sounds likely that the coolant level is low, or that the coolant level sensor is faulty. The red light flashes under three different (normal) circumstances.

1. On starting the ignition for a few seconds or so.
2. If the coolant level is low.
3. If the coolant temperature gets too high - assuming that the gauge/indicator and the temp sensor are working correctly this would normally happen after the needle on the coolant gauge gets about 3/4's of the way up.

There's no way your engine will be overheating after only 10 minutes so I would expect that the light is indicating a low coolant level.

What you need to do is check the level in the expansion tank. This is the tank that is located inside the engine bay, NOT the one behind the registration plate flap. The level in the expansion tank should be right to the top, so it's spilling out the top when you screw the cap back on. Top up with distilled water if possible and use some antifreeze too if the level is extremely low - you don't want to dilute the antifreeze level too much. However be careful what antifreeze you use as it can be a bit of a can of worms. Have a look at the WIKI for advice.

If the level was fine to begin with, or if topping up has no effect on the light problem, then it is possible that the coolant level sensor is buggered or maybe just dirty. The sensor is screwed into the top of the expansion tank. Unscrew it and give the two prongs a clean with a tissue or something - they can get a bit grubby over time. If this still doesn't work then consider replacing the sensor itself, they are only a few quid from brickwerks and very easy to fit.

Let us know how you get on.

[Emma&Al]

Hi Roydini,

Thank you so, so much for this advice! It is something constructive that I can do instead of just worrying about it every time I drive. I like to be able to do things myself but am a complete novice. Thank you! And sorry for hijacking this thread slightly

[300CE]

No worries Emma, good luck with it and keep us informed on how you get on and if you need any further info.

[Ian Hulley]

Hi Emma,

It sounds likely that the coolant level is low, or that the coolant level sensor is faulty. The red light flashes under three different (normal) circumstances.

1. On starting the ignition for a few seconds or so.
2. If the coolant level is low.
3. If the coolant temperature gets too high - assuming that the gauge/indicator and the temp sensor are working correctly this would normally happen after the needle on the coolant gauge gets about 3/4's of the way up.

Or if the plug comes off the top of the sensor.

Ian

[Emma&Al]

So I've just looked in the engine - the tank that you fill via the number plate hole was EMPTY! I filled it up a month back. The actual expansion tank (that is the one under the engine lid, right?) was inbetween Min and Max... but I was unable to take the lid off because the screw cap lid had a very old knackered looking bit of hose running from there to the other water tank...is that normal? I couldnt spin the lid to get it off because the hose running off of it wouldnt allow for that. Surely I dont have to undo the water hose and re clamp it every time i fill it?? Seems odd to me. SHould it be on there?
Thanks all - ill have a look at the sensor at some point today.

[randiandipandi]

Hi Emma.
The tank in the engine bay should be full. The cap on this tank is a pressure switch - when the water heats and expands it allows water down the tube you are referring to into the tank behind the number plate. When the pressure is low in the main tank it sucks water out of the number plate tank.
You can pull this tube off the tank cap without losing coolant - so you can then unscrew the cap. Your flashing light may well be caused by this tank having a low fluid level.
Any help?

[300CE]

Hi Emma, as Andi says the tank with the hose running from the cap should be full to the brim at all times so that it is literally coming out before you re tighten the cap. I always check this tank after I've been out in the van whether it's a 5 minute run or a 2 hour drive. The top up tank behind the cat flap should be half full.

[ghost123uk]

I always check this tank after I've been out in the van whether it's a 5 minute run or a 2 hour drive.

But note Emma that, when checking that tank, the one over on the left hand side, if the engine is hot, be careful as boiling water can spurt out when you remove the cap. I keep a weekly eye on my top up tank, but I rarely look at the main tank in the engine bay, but I would if I thought I might have a problem. These engines do need the cooling system to be in good order.

[300CE]

I always check this tank after I've been out in the van whether it's a 5 minute run or a 2 hour drive.

But note Emma that, when checking that tank, the one over on the left hand side, if the engine is hot, be careful as boiling water can spurt out when you remove the cap. I keep a weekly eye on my top up tank, but I rarely look at the main tank in the engine bay, but I would if I thought I might have a problem. These engines do need the cooling system to be in good order.

Indeed, as John points out if it does require topping up then allow time for the engine to cool and if you are still unsure, unscrew the cap very slowly as it will hiss and you will be able to see the fluid rise if it is still hot.

[Ian Hulley]

The header tank in the engine bay MUST be full at all times .... if you've allowed the top-up tank to run dry then you need to do 2 things ... 1) fill the header tank to the brim when running at fast idle and the top-up tank to the 'Max' line. and 2) check your fluids properly at regular intervals ... slacking off on that minor job will lead you down a very expensive road to newengineville before very long. Do you check the engine oil regularly ?

Ian.