Coolant level low

Likely is NOT a problem.......IF things were good and cold at the time.

Look at them again after a good drive when things are HOT. If they are up near the FULL mark then, you should be fine.
It certainly will be fine until your next service, when the dealer can add a bit for you.

It is normal for the level to vary from low/cold to full/hot........for almost any engine.

 

Checking my log, at 51K kms (around 30K miles) and 4.5 years, my (2010 Prius) engine and inverter coolant reservoirs had both dropped to slightly below the low marks. The were both at the high mark at time of purchase, new. I purchased a gallon (of Toyota Super Long Life Coolant) and topped them both up to the high marks.

Around 82K kms (around 50K miles) now, and neither coolant level has dropped any more, at least not enough to tell.

My guess would be there's a slight amount of expansion happening in all the hoses, for some time after manufacture, and this is what drops the level some? Plus a slight amount of evaporation.

 

You might check it hot and see how high they go.

However. I just looked at mine. The car is "cold." (Remember, I'm in Florida, so nothing is actually cold.) Both tanks are at the full line. In fact, the ICE tank is a smidgeon above full. I have never touched either of them and there's no record of the original owner doing so either even though he/she had it in the shop every 5k miles for scheduled maintenance.

If this is the first time you've paid any attention to them, it may be that the car came that way new. If the level has dropped from your last check, then that's something to check into. It seems odd that both would have leaks, though, since they are separate systems.

 

I believe you're supposed to check coolant levels when COLD. Thus you should add at least to the MIN line on the engine coolant. Inverter coolant appears to be at MIN level. BTW, it's pretty important, according to this forum, to use genuine Toyota coolant--don't try and save a few bucks with after-market. I believe they sell pre-mixed at Toyota, so just add straight to the reservoir when cold.

 

I just checked mine. Cold vehicle, both levels at the low line, 30,000 miles. Never touched that I'm aware of. Looks like I need to add some.

Page 584 of the manual says the coolant level is satisfactory if at or between the Full and Low marks when the vehicle is COLD.

 

Just found out that all the dealers in my area carry the Toyota SLL"Pink" 50/50 premixed coolant for $21.12 plus local sales tax. Part #00272-SLLC2. Each jug is 9.34 lbs so on-line shippers tend to charge a lot for shipping. The local price is pretty hard to beat.

PS, for those of you that own(ed) older Toyotas and have leftover supplies. Do not use Toyota "Red" coolant and just dilute it. It is NOT compatible with the hybrid internal metal components and will cause severe corrosion and cost you BIG $$$$$$.

 

The only problem with that IS...........that usually the cooling loops use exactly ZERO coolant over a very long time.
So you end up with most of the gallon totally wasted.
Your dealer should be checking the levels and topping up as needed at each oil change.

 

I'm past the free service and I do all my own maintenance on all three of my Yotas. Always have. At only $21 it's cheap to have on hand. Heck, I even still have a small amount of "Toyota Green" left from the time before they switched to Toyota Red in 1996.

 

Yeah I just bought from our nearby dealership: 4 liter bottle was $19.14 (CDN), in April of 2015.

And up here the mix is 55% coolant. It's a little odd, how just north of the border we get all the deep-freeze stuff, stronger anti-freeze mix, block heaters and so on. Our west coast winters are a lot milder than Fargo, North Dakota. Or Anchorage, Alaska...

 

Hi Yoyoman, The engine coolant level in my 2017 Prime looks identical to the that in the pictures you took at the top of this post. Was it ever determined if this was problem? Did you top it up? Thanks, Bob

 

Mine old Prius was similar. I asked the dealer and they said don't worry about that it was normal to have slight variations in levels.

 

Well that is basically true, UNLESS all of the "slight variations" are lower and lower and LOWER.

 

Update: Since I was driving cross country I wanted to top it up. I went to the Toyoto dealer in Casper Wyoming to purchase the specified coolant; but when I went to do the top off, the level was back to FULL! The guys in the parts dept were super nice; they took a look at the level and explained it was normal. They even took back the gallon of coolant I had just purchased since I hadn't even opened it. I then drove 2000 miles back to NY. No problems at all. Summary: it seems normal that coolant level will fluctuate between Low and Full. The key is that it not drop way below the Low line and stay there or go lower.

 

That's exactly the reason for that tank. The coolant level is not constant, so it provides temporary storage.

 

The coolant level in the "overflow bottle", which is what you are looking at.......will go UP when the engine is HOT and back down when it is COLD. Many of those bottles have the top and bottom lines marked HOT and COLD.

So......best to check it COLD. But if the level is down near that bottom mark when HOT, then you likely need some added.

Note: which is pretty much what everybody has been telling you for the last year, starting with my post #2.

 

Unlike a typical overflow tank, I've never noticed a lot of level variation. Maybe 1/4", hot vs cold?

To be fair, the horizontal cross section of the Prius bottle is a lot more than the typical (tall/narrow) overflow bottle.

 

Now that you mention it, I haven't seen much change either and the width may be the reason.

My Prime has a more traditionally shaped overflow bottle, but I haven't paid any attention to hot vs cold levels.

 

If your coolant reservoir should look like this, if not your cooling system is not bleed. With pressure in the system (cap on and hot) loosen with 6mm hex wrench bleed screw on top of reservoir and let air bleed out. Tighten when done.