Low Coolant Temp Warning Light + Demisting

[Xenole]

Bit colder yesterday and when I turned the engine on in my Yaris, the blue "low coolant temp" light came on for 5-10 minutes. Is this supposed to happen if the car/engine is cold? If so, is it just a matter of warming up the car and is it safe to drive with it on at first?

Also, cold again last night and a lot of icy water covering all the windows. Wiped the majority of and used the wipers to clear other bits.

Got the heater on and air being sucked into the car (window heaters on too).

Are these the right settings as the windows seemed to steam up at first before improving but by that time you're nearly home unless you sit around in the car park for a few minutes?

[Dougs]

The low coolant temp light always comes on in mine if it hasn't been driven in the last 30mins and i went out last night and mine stayed on for 5-10mins aswell so would say its normal

Not sure if you have air-con or not but if you have put the temp on cold put it on windscreen vent switch on the air-con and stick it on full blast should clear the the screen in no time at all

[T V O R]

The blue light stays on for about 1½ miles in this sort of weather, just keep the revs low and drive nice and steady until the engine is at normal operational temperature.

I think it’s a great feature (the blue light) never seen it before on a car.

If you want to clear you windows in double quick time use the A/C (hot setting) this also doubles up as keeping it working properly during the winter months.

Problem is the windows seem to steam up quicker when you turn it off!

[Viper_7]

As said with the Temperature light...5 mins sounds about right...10 mins sounds a little long. Drive away as soon as it's safe to do so though....leaving the car standing for five mins isn't ideal.

If you don't have air-con then you need to remove the excess moisture other ways.

First need to determine why it's so humid in your car. Check you don't have any wet gear in the boot etc or whatever.

Make sure the windows are properly shut when you park up. Also a good idea to close the airvents.

Now to get rid of the moisture that's there already... get the heater on high and open your windows a good inch.

Bascially what your after is the water evaporating..and then been let out of the windows..otherwise it will just condense again on the windows when you park up.

If you can do this for say a good five miles then you should see improvements immediatly...after that it's just a matter of keeping the interior dry.

You should never need to be in a position where you need to wipe the inside of the car...this will just make it hard to see when the sun's low.

If your still having problems...need to check the door seals etc.

Winter TIP guys.

Rub a little talc onto your rubbers!. Stops them sticking in the cold!

Vipes

[Blue84]

This morning mine stayed on for about 5 mins. There is a certain bus stop just past a roundabout near me and it always seems to go off around the same stop which is odd!!

[clarky]

Mine stays on a bit longer in the winter - but only for a few minutes ... not ten - even in the real cold mornings.

Clarky

[sup2]

dont worrie bout it peeps its just as the cold weather sets in the engine is sitting in colder air so it taks a bit longer to get up to temperature, perfectly normal

[Victoriawil]

Morning everyone,

I have a lovely Toyota Yaris 02 reg which I love.  It has just been in to have the radiator drained and new coolant put in.  Everything was fine until this morning - it was very cold and the blue temperature light was on as normal when I started it and then went off when the engine warmed up.  Then after about 15 minutes the blue light suddenly came on again.  Why would this happen and does it mean there is something wrong?

[bathtub tom]

Yes, check your coolant level. If the coolant level drops enough the sensor isn't covered and can't detect the temperature. Anti-freeze reduces the density of water and is more likely to leak. Perhaps whoever did the job didn't ensure there were no leaks after?

[Guest]

Whoever drained and refilled possibly didn't "burp" the system completely. The engine has to be run up to operating temperature with the radiator cap off, squeezing the top and bottom hoses at the same time to help expelling air. As Bob writes, there might be air trapped at a sensor. Don't know about a 2002 car whether there's bleed points in the system or a separate pressurised tank as well as a radiator cap?

[TonyHSD]

Agreed with Peter, 

why was the coolant change and was the thermostat or water pump also changed? If you want to make sure there is no air locked into the system you will need to do following steps: 

1. Turn on engine and let it idle 

2. Set heating to max temperature and blower speed 1

3. Open bonnet, undo the radiator cap or reservoir cap wherever you top up coolant usually make sure you have coolant at max level always, leave cap open , keep watching level drops and top up. Carefully check radiator hoses top and bottom gets hot , can squeeze a bit but not necessarily important, the engine should run until gets past operating temperature, thermostat opens and second loop start recirculating through the front radiator and cooling fans kicks in and start spinning, be careful with that and don’t push your fingers there. It may take more than 30 min in cold weather to complete this procedure. 👍