Low Coolant light is on, Please help out.

Tideland has got you covered. That blue light will always come on at startup unless your coolant is above about 70 oC. When winter comes, it will stay on a bit longer. There is also a red/orange light with the same design that would come on if the coolant temp got too high. I don't know of anyone seeing that light while driving.

To check your engine coolant level, confirm that the big white plastic reservoir on the passenger side of the engine compartment is about half full of red/pink stuff.

 

<div class='quotetop'>QUOTE(fortysixandtwo @ Aug 25 2006, 08:47 AM) [snapback]309102[/snapback]</div>

Yes, it is normal and safe to drive with the Low Coolant Temperature Indicator Light on, not necessary to leave the engine idling to warm up.

Unless the light doesn't turn off at below conditions:

1) When the engine starts, the coolant temp. is between -7ºC (20ºF) and 10ºC (50ºF). And, 5 min. or more after the engine starts, the temp. sensor value is 5ºC (41ºF) or less.

2) When the engine starts, the coolant temp. is -7ºC (20ºF) or less. And, 20 min. or more after the engine starts, the temp. sensor value is 5ºC (41ºF) or less.

 

I bought my Prius in January, and have never seen the blue light. Does it not get cold enough in California, or what? I've started the car at near freezing weather, and never saw a "cold" blue light. What gives?

 

Subarutoo, your 2006 Prius has a different display system, so one of these young whippersnappers is going to have to provide that answer.

 

<div class='quotetop'>QUOTE(subarutoo @ Aug 25 2006, 01:04 AM) [snapback]309197[/snapback]</div>

There is no blue light on the 04-06 Prius. And it is a low coolant temperature light not a low coolant light. They were on GM products in the late 50's and 60's instead of a temperature gauge. It is only a problem when it stays on for a long time. (Probably means the the thermostat in the engine is not closing properly.)

 

The more I read this topic the more scared I get.

Low coolant is unusual at 55,000 mi?
You do change your coolant, don't you? It shouldn't be in the engine for more than the above mileage (unless you're a very high mileage driver).

Ethalene glycol coolant (usually green) should be changed every two years.

Propylene glycol coolant (usually straw) should be changed every five years.

Do NOT use RV system anti-freeze as coolant. It will corrode your system.

Failure to change the coolant WILL result in coolant leaks. It will be caused by corrosion eating holes through the metal of your engine and/or radiator!

No car should loose coolant in normal operation. The only time it could be lost is if:
1. You overheat the engine and it overpressures and this overwelms the overflow capture tank.
2. You have not changed worn out coolant hoses and one bursts.
3. You have a gasket failure in the engine - coolant then can either leak outside and drip onto the pavement, or can be inhaled by the engine and burned.

Warning - coolant is flamable. Leaks are not a minor matter. If coolant leaks onto hot exhaust parts it could start a fire! Leaks are also an environmental problem. Coolant is toxic, and many animals will lick it up as it tastes sweet. It will kill them!

 

fortysixandtwo, your 2003 Prius uses Toyota LLC coolant (red) in both the engine and inverter coolant loops. The specified life is 30k miles. I would not react strongly to minor variations in level of the overflow reservoir unless there was other evidence of leaking.

The new Prius used Toyota SLLC pink coolant (for both loops), with a 50k mile change interval. The classics can switch to that, and enjoy the longer conge interval. I have not done so yet, in fact about 3500 miles past due for a coolant change. But it remains very clean and I do not feel any sense of urgency.