Losing Coolant

[Kevin jones]

Hello everyone,

I have a toyota auris 2011 1.8 hybrid 

and i bought it about 7 months ago.it’s about 5 weeks that i was hearing(SOME DAYS) a rattle noise when i was starting the car just FOR 2 seconds.i thought its because of temperature (10 degrees)!!

but it’s 2 weeks that i understood also that the radiator loosing coolant but I can’t see anything on the ground or inside of the cabin and also mechanics checked pipes !!!

when i start it smoking and i think it’s water drops even after 15 minutes driving but is not too much…

is it head gasket problem???

[Maurice Mynah]

If there's no evidence of an external coolant loss then I would suggest it's leaking internally, e.g. head gasket failure. At 10 degrees ambient I wouldn't expect "steam" out of the tailpipe. It's been less than 10 degrees where I am and no "steam" on starting. That looks like steam rather than smoke.

How's the engine oil for level and condition? Any "mayonnaise" under the engine oil filler? Can you remove the spark plugs and check their condition. i.e. do any look "steam cleaned"? If possible, a look inside each cylinder might reveal any issues. Ideally that needs a camera though.

[Saxmaniac]

They have a lot of head gasket failures in America, look on Prius chat forum under Gen 3 Prius. There's people on there who know their stuff and plenty more who think they do so watch out for dodgy information. Car care nut videos also from someone who does know his stuff. You want to diagnose it properly rather than just guess, CCN puts bore scope in cylinders while cooling system pressurised and can see small drips from head to block seal 

[solero]

Dont let it get any worse if it is the head gasket. After a hot run, the coolant pump can overrun and fill a cylinder. On startup t can get hydrolocked, and mg1 can bend a rod as it's much stronger than a normal starter motor.

[TonyHSD]

What is the mileage?
How much coolant is using? 

The steam is normal and on these cars can be seen even in summer time especially if you drive at nights when temperatures here are below 20C°. Head gasket can fail on any car. In America it’s not only Prius the car with head gasket problem but all makes and models. The reason is higher air temperature in some areas and poor driving style. Head gasket goes by two reasons- overheating and overloading- too much boost. 
The engine knocking can be as a result of more things, more fuel - bad injectors, the exhaust will smell of unburned fuel,    
coolant inside- bad gasket,    
poor quality petrol like the majority of uk e10 95 , use only e5 97 bp, Shell, esso.  
Blocked egr system - complete egr system clean up . 

 

[AisinW]

If you suspect head gasket, Do pressure test from the radiator/coolant reservoir. You should see water dripping slowly in the head gasket area inside the cylinder. 

What is the mileage and how often you drive in cities?

It is hard to tell from the video because it is pretty cold at 10C. But you can compare with other cars at that temperature. Hybrid should emit about the same amount of water in idle.