How much coolant loss is normal?

When I got my 2019 awd-e brand new at 10 miles on the odometer, and then I noticed that the ice coolant level went down to Low by about 2-3000 miles in. I topped it up to the Full level, and at 100000 miles, it was still at Full level. I then drained and refilled the coolant using a UView airlift and filled it to the Full level, it again dropped to Low level by after a few drive cycles. I topped it up to Full level and it hasn’t changed since, may be 3000 miles in so far since the refill. May be it purged some airpocket somewhere and that caused it to go down?

 

I’d top it up (with the right stuff) and continue to monitor; it will hopefully be stable now.

 

Hello, I live in Switzerland and have a 2016 Prius 4 which I bought used last year. So far, all is good and it is a great car. Last week I took it to its yearly inspection to the local Toyota garage and they told me that all was fine but that they had to refill 200ml of coolant. When I asked if this is ok they told me it's all fine and normal. My understanding, however, is that coolant loss/drop is NEVER normal and under normal circumstances should not need to be refilled. So I went through the old inspection protocols from the first owner and saw that in 2021 already, the Toyota dealer had to replace 500ml of coolant. So my Prius is losing about 100ml of coolant per year (700ml in 7 years, 500ml in the first 5 years, 200ml in the 2 years thereafter). It had its inspections timely every year (every 15t km/ca. 10t miles). I suspect it might be the initial signs of the now almost "famous" EHR leak problem? Should I worry? What would you advice me to do? In Switzerland, the EHR system is explicitly excluded from the (ongoing) 10 year extended warranty we have here. The car has 73t km (ca. 50t miles) now. Thank you very much for your replies and help!

 

I think you’re fine. Just note the level of the coolant now and keep an eye on it going forward at the same engine temp. I’ve had to add about 200 ml of coolant after 5 years. It’s been a year since adding it and it hasn’t changed since.

I think we’re all anxious about the Exhaust Heat Recovery System leaks we’ve been reading about. Although it’s a known problem, for some reason, it only affects a very small percentage of cars out there.

 

The manual for my ‘22 gives a coolant capacity of 6.2 liters, so a loss of 700 ml in 7 years isn’t bad. To help alleviate concerns having the coolant replaced will help prevent corrosion in the system (or help slow it down if it is already occurring.

 

I also got one from Switzerland. 2017. Around the 5 year mark just out of warranty and 30k miles I noticed both coolants were slightly below the lowest mark. Dealership in Portugal over the phone told me probably a leak and that as long as the light is not lit on the dashboard it's fine lol but correct if I'm wrong if the light is lit you already have an overheating engine and it's quick to get irreversible damage and have to replace the engine. Anyway got them to top it up and it didn't move for a long time, and just this summer when temps started to go up it went slightly above the full mark. I also did the heat exchanger bypass directly on the engine following the headgaster masters tutorial on Youtube and intend to let it like this for life, praying that it doesn't ruin anything on the long run but didn't find any warnings about letting be like this forever. My guess is every time you change the coolants it takes some time for the levels to stabilize, it also depends maybe on outside temps and because the engine is new you might have to top up a few times as well as every time you change the fluids but then it should be stable unless there is a leak, maybe it also depends on where the fluid was in the cycle inside the motor/hoses at the time you checked so if you check it multiple times you'll maybe have slightly different readings up and down.

 

Thank you very much to both of you for your replies. This calms me down . From now on I will check the coolant level regularly and take the prius to Toyota should the loss rate increase. Greetings from Switzerland

 

Yeah that's what I do too check them every other day when the car is cold and at flat surface. Greetings