Hey all, My 2011 prius coolants is near the minimum mark; is there more to topping it off the coolant reservoir than just removing the cap and filling it with oem coolant? am i done after tightening and closing the cap? any other concerns? Thx in advance.
Our '10's levels, both engine and inverter coolant reservoirs, both slowly subsided to the low line, over about 4 years from new purchase. That's all I did: purchased a gallon (well 4 liters here) of Toyota Super Long LIfe Coolant (pre-mixed with water), and topped both up to full lines, caps back on. Maybe. How long have you had the car, since what miles/date? What's the miles on it now? Gen 3's (model year 2010 through 2015) have a propensity to head gasket failure, typically around 150~200K miles, in particular if the Exhaust Gas Recirculation system (including intake manifold) hasn't been cleaned. The head gasket failure typically involves coolant leaking into the combustion chambers.
It could be as simple as the water pump beginning to fail. Don't get too worried about head gasket failure just yet. It seems that any mention of coolant loss on this forum generates replies of head gasket failure. It may be common on these cars but it's not always the problem.
How many miles on your car? Do you have any knocking on when the engine start when cold, or hot? If so, you could have a failing head gasket. Look over the whole coolant system and see if any of the hoses are leaking. And of course around the coolant pump. Check the radiator closely. Hopefully, you just have a loose leaking hose, or leaking radiator.
Absolutely. It's not always the headgasket, even if he has over 200k miles on it! Maybe it is, maybe it isn't. There are other reasons for these engines (of any mileage) to have coolant loss.
Has around 150,000 but i did a full coolant replacement over a year ago. A couple years prior to that, i’ve had my prius make a violent shake of the dash and immediately turned off the engine and rest it. to make it work; guess this is the head gasket issue, huh? But my car is running fine ever since besides noticing for the first time that the engine coolant had dropped its coolant level a couple inches below the min mark.