Correct level of engine coolant?

There's confusing pink tint up the wall on right side, maybe due to the return hose? I think the true level's near the top mark, looking near the middle. I would wait till it's at the lower line before doing a top up. The min you can buy is a gallon, the stuff specd in Owners Manual.

I took the liberty, rotated the pic:

 

I rotated it, too. My coolant level doesn't look like that. Very strange. The fluid in mine is straight across, regardless of how long the engine has been on, or off.

 

Forgot to add, even after driving awhile the fluid always seems to be nearer to the "minimum line."

 

That is sure odd. Were you parked on a hill or something??? Or is the top plastic part just stained?

 

Maybe there's an internal baffle on the tank where that hose enters, to prevent splashing, and it stains there?

 

I don't know, Mendel. I defer to your mechanical expertise. I will keep an eye on mine and see if it ever does that. (Sorry I posted the same pic as you. Yours hadn't appeared when I posted. PC glitch I guess. Thanks for straightening it out.)

 

Now you got me curious. I'll take a look under the hood once a week, or every time I get gas. See what it's doing. (I need to check the oil anyway.)

Have you noticed the water accumulating in your headlights yet??? Some guys even put Goldfish in there!












(Kidding. )

 

It doesn't look like a problem to worry about. The hose in the photo is the overflow hose; the coolant doesn't need to be that high. The reservoir is designed to hold both cold and hot (expanded) fluid. It looks fine, but show the dealer when you next bring it in.

 

There's a hose at the bottom of the reservoir the fluid is drawn out through, and when there's excess in the radiator (hot and high pressure) it comes back through that top hose. I'm guessing the dye in the coolant is staining the wall where it comes back.

 

I wouldn’t think so, unless there are coolant stains on the outside of the reserve tank (reservoir), other signs of leakage near the cap, a coolant level far lower than seen in your pictures, or steam rising from under the hood.

The operating conditions experienced by your Prius—factors such as outside temperatures, engine temperatures, trip lengths, engine speeds, and vehicle speeds—determine the volume of coolant returned to the reserve tank during the normal operation of the cooling system.

Unless the coolant level drops below the “LOW” line, or some other malfunction occurs, there may be nothing to fix. I’d suggest leaving well enough alone, since even careful servicing carries some risk of causing other trouble, or worse yet, personal injury.

That said, Toyota’s Repair Manual (available by subscription to techinfo.toyota.com) does explain how to check the valve opening pressure of the reserve tank cap (see 2ZR-FXE Cooling: Radiator: On-Vehicle Inspection) and how to check for coolant leaks (see 2ZR-FXE Cooling: Cooling System: On-Vehicle Inspection). Both procedures require a radiator cap tester and suitable adapters.

If the coolant level is between the “FULL” and “LOW” lines on the reserve tank, with the engine cold and the car parked on level ground, then the amount is correct. I’m not aware of any other measurement procedure.

If you’re still concerned, I’d suggest buying a gallon of Genuine Toyota Super Long Life Coolant (00272-SLLC2) and a funnel, just to keep on the shelf in case you need them, and checking the engine and inverter coolant levels every few weeks, at least until it’s clear there is no serious adverse trend.

 

4 Honda hybrids and 5 Prius and I have never needed to add coolant. Think the dealer does that at your earl change.