Coolant Heat Storage Tank and Pump Question

My 2009 Prius was recently totaled and I purchased it back as a salvage vehicle (I posted a thread that details that event). Anyway, the heat coolant storage tank was dented in the accident. Since there was no fluid leaking and no codes errors popped up on the screen, I chose not to replace the tank. I've also driven the car an addition 100 miles in the GA heat without any issues.

However, is there an easy way to verify that the pump/system is still working? Or is the fact that I did not encounter any errors or find any leaks adequate?

 

Thanks all. I now feel more comfortable just leaving it. So the weird noise I would hear on turning off the car is this pump and not the inverter coolant system? I'll try listen when I turn it off next time.

Patrick, interesting tidbit about emissions control. Sounds like the car will still be perfectly functional if this coolant tank was bypassed.

I've seen several listed on Ebay for $50 - $100. The problem is that I wouldn't want to replace the tank and fluid myself - I recall reading that some type of vacuum system was needed. I know there's a DIY method, but I'd likely get someone with the right tools to replace. However, I already called a hybrid specialist in Atlanta for a quote and was told that they do not allow customers to bring their own parts. So if I get it done, I would need to find a reasonable local mechanic with the right tools and preferably some Prius experience - if anyone has recommendations, pls let me know.

 

I just got my totaled (now repaired) Prius back, drove it about 30 miles home in mid 70s temps. As soon as I got home I listened for about 30 seconds for any sounds coming from the engine bay, but could not hear anything. Still no codes or check engine lights and the car felt great. I'll take another listen, tomorrow.

 

Is there another way to verify that the coolant pump is working besides simply listening? The last two times I've driven the car, I've heard a whirring noise, immediately after powering off the car. However, this noise only lasts about 3 seconds. Previous to the accident, I recall hearing a whirring noise for up to a minute after powering off - maybe I only noticed this when it happened and it actually did not occur all the time?

The weird thing is I did notice another noise after powering down and immediately popping the hood - a faint high pitched noise that seems to be coming from close to the wiper fluid tank. This noise is intermittent and disappears after a minute or two. Any ideas? No leaks were evident anywhere.

 

Patrick, yes the CHRS pump. So this pump only activates for a few seconds on startup and shutdown and does not run at all when the car is running? I'll look into using the relay to test the pump - I just read the thread on replacing engine coolant and noticed that method is detailed there. Since I want to double check that all the plug connections to the pump are secured, I also may just take off the plastic covers under the car, start the car, then quickly jump out and feel if the pump vibrates at all - or better yet get someone to start the car while I am touching the pump - hopefully, not too hot. By the way, is there only a single electrical connection to the pump or is there also a separate connection to the pump sensor?

Concerning the high pitched whistling noise - this seems to emanate from closer to the wiper fluid tank than the radiator cap - I'll check again.

 

I just pulled down the front of the driver's fender liner, started the car, and within 5 seconds put my hand on the CHRS pump and did feel a vibration for a few more seconds. I then shut down the car, rushed to the pump, but could feel no vibration...perhaps the car was not on for enough time for the pump to fire at shutdown? Well at least the CHRS pump seems to be functional.

JC, if the high pitched noise is coming from the passenger side (near the wiper fluid container) wouldn't this indicate that it is not due to the CHRS pump? I am suspecting something related to the AC system and will also double check Patrick's suggestion on the radiator cap. I'll investigate further after taking the car for a drive.

 

I've just returned from a 20 minute drive and checked again on the high pitched whistling noise after shutdown. The noise was evident for at least 5 minutes after shitting down. Its really tough to pinpoint exactly where it is coming from, perhaps closer to behind or under that relay box (CHRS relay). Or as mentioned previously - maybe in the vicinity of the wiper fluid tank.

 

I googled for solutions and found a 2016 thread that detailed the exact same issue with the high pitched noise! Reading through the thread, the issue was also not definitively resolved. Now for the funny part, I then recognized the poster of the thread - yup it was me. I must be losing my mind, but two years ago I posted an almost identical thread and clean forgot I had encountered the same issue!! Well, about 25k miles later, I'm going to try forget about it again and assume its just some typical Prius noise.

2016 Thread

As far as the coolant tank is concerned, my plan is to switch it out within the next 6 months.

 

I decided to go ahead and order a used replacement coolant heat storage tank. To gain access to the existing tank, after draining, is it necessary to remove my headlight in addition to the plastic shield and fender liner under the car?

I ordered a unit off a 2008 Prius with low mileage - I recall reading that there was a recall on the CHS pump for some years - anyone know if I would need to worry about a 2008 model? I could keep my existing pump as it seems to be working.

 

Car has about 85k miles and I had planned to replace the engine coolant at 90k anyways (its never been replaced). The tank is quite badly dented so there is a chance that its integrity has been compromised. I'll fully inspect the pump and if there is no physical damage to it, I may keep it and only replace the tank.

Also, the used tank comes with a pump.

 

JC, are you recommending that I should leave in both the dented existing tank and the pump even when I replace the engine coolant? Even if this is your recommendation, I'd still face the bleeding air challenge when I change out the engine coolant.