Inverter pump/coolant flow question

Poor circulation means the pump is on its last legs. And like you said its not warm yet so has not thrown any codes yet. But it will.

Fresh inverter coolant should look like its boiling in the reservoir. I would proactively replace the pump and coolant. Use the OEM pump. Few on eBay. You already know how to bleed it properly.

While your at it remove the black plastic cover over the ICE radiator to get to the rad cap. Disregard the levels in the rad overflow tank thats meaningless for some reason in a G2 the rad could be empty and the overflow full. best to look inside the rad itself.

You can leave the screws off that cover just fit it back on. The hood closed on it will hold it tight. No screws on my cover for about 10 years now.

At least once a week I check the engine oil peek in the inverter reservoir and check the rad coolant level. keep the oil at the full line and the ice coolant at the top of the fill neck.
This routine has served me well never any issues under the hood.

My original pump was replaced under the years old pump TSB. Have 75,000 miles on it. Inverter coolant looks like its boiling. There will be a remarkable difference in circulation behavior between new coolant and what I suspect on your car the original coolant.

 

As a single data point, I've never noticed this boiling effect before. My OEM pump produced slight movement on the liquid surface area.

I did replace a still working pump when a P0A93 appeared and cleared for no known reason, the aftermarket pump had the same movement.

 

SFO mine looks exactly like its boiling to a slow roll. It has no air in the system I bled it good. Much more agressive flow then the stock pump. I have tried posting a picture of it but cannot get the PC system to accept it. Even used a compression ap on my iPhone video still no go.

To the OP yes looks like the car has had all its TSB updates including the steering shaft replacement and the inverter coolant pump. And they chopped the bottom inch off the gas pedal too which is that pedal safety check. back in the day during the Prius runaway car uproar disaster it was found the front floor mat would bunch up under the gas pedal and jam the gas pedal in the floored position.
So they cut the bottom of the gas pedal off so a mat could go under it with no issue.

But just because they replaced that pump years ago doesn't mean that one now hasn't failed. Very very common to lose that pump.
Especially since the last pump was replaced by the dealer because they do not flush and bleed the system they use duckbill pliars and clamp off the input hose and slide a new pump in. So the car probably has the original invert coolant in it. That Inverter fluid is very abrasive after initial new car break in and that will kill a pump.

It needs a new pump and complete flush of that coolant and refill with Toyota LLC coolant.

I threw in a bottle of Redline Water Wetter in mine. Great product. I use it in the Ice coolant too. Inverter now runs very very cool about 100 degrees cooler than the engine temp in the dead of Florida summer.
There is a very big spike in temp when you shut the car off the rad heat soaks the fluid. Both the rad and the inverter coolant share the rad in separate containers. They fixed that in G3/4 models by using a separate inverter rad.

Good news you will get a bump in mileage with new coolant. Cooler the Inverter is the happier and more efficient it is.

Good luck.

 

well done!

 

You should see a bump in mileage too.

 

The OUTlet of the Inverter/Converter is the INlet of the reservoir, so any restriction between the pump and reservoir can cause this. I happen to have a photo of a partially blocked cooling plate from either poor maintenance or contamination.

 

hm.. i should see if my inverter have a good flow too. lol

 

The inverter coolant loop It has a huge cross section of aluminum cooling channels under the inverter. There very small Like 05 shows best to keep the fluid in tip top shape.

I refer you to the excellent Weber Auto tutorials on the Prius on youtube. Just search Weber Auto on YT. They dissect a G2 and G3 prius and talk in length about there systems. Very informative.

 

Yup! Professor John Kelly is AWESOME and I am glad his College allows him to not only make, but publish all those videos!

Linky: WeberAuto - YouTube

 

You remove the inverter, drain it and pull the bottom plate (not the sheet metal cover) off.

HOWEVER, I DO NOT recommend it! That plate can be difficult to reseal and there is a potential to damage the electronics in the inverter.

 

Go see Webers videos its amazing how much cross section of cooling channels they get in that block. All pure aluminum which is very very hard on the coolant at least when its new. Raw aluminum in solution. Very abrasive. I surmise thats why they issued a TSB on the pump.
After the initial break in fluid is replaced your good to go for the life of the car.

 

so i went out today to check my inverter coolant reservior to see if theres any flow let me know if i need to change mines.

Engine running

Engine not Runing

 

Looks good to me. No need to worry for a while.

 

You have FLOW!

It is not that the factory coolant causes the restriction, but CONTAMINATION of it that does. Despite what one may read on the interweb and while it *might not* do damage in some situations, mixing coolant types is NOT GOOD.