Odd "Thermos" Behavior

ekpolk · 09-14-2006, 12:25 PM

OK, I've just finished getting used to all the fun little Prius quirks, such as the post-shut-down hum that is the coolant pump transferring the 3L of hot coolant into the insulated storage tank (a/k/a thermos). No problem with that; actually, it's sorta fun to explain to wide-eyed, envy-feeling friends, as I'm sure y'all understand.

Then it stopped.

That's right, a couple days ago, my car seems to have stopped transferring the hot coolant to the thermos. That pump is totally silent after shut down -- nothing at all, not even a gurgle. The coolant level is fine, both hot and cold, and I have no warning lights (so I assume it's throwing no codes, but I haven't had it plugged yet either), and no other noticeable symptoms (prolonged warm-up, etc) at all. Just no apparent filling of the thermos.

Anyone got any thoughts on this? I'm not really worried, since otherwise the car is behaving fine, but still, I want to know what's up with this. TIA for any clues, suggestions, or solutions.

galaxee · 09-14-2006, 01:01 PM

if you drive more than just across the parking lot or something, you should hear the pump run. if not, take it in to the dealer and they can force it to run with the scantool to check and make sure it works.

**Tideland Prius** · 09-14-2006, 05:26 PM

It doesn't always run after you shut down. It'll only pump if the coolant in the engine is warmer (and above a set threshold) than the temperature of the coolant in the thermos.

ekpolk · 09-14-2006, 07:33 PM

<div class='quotetop'>QUOTE(Tideland Prius @ Sep 14 2006, 04:26 PM) [snapback]319736[/snapback]</div>

Quote:

It doesn't always run after you shut down. It'll only pump if the coolant in the engine is warmer (and above a set threshold) than the temperature of the coolant in the thermos.
[/b]

Hmmm, it has cooled off substantially here in the last few days -- maybe that's keeping the engine just cool enough to prevent the transfer. Thanks for the info.

hdrygas · 09-14-2006, 07:56 PM

<div class='quotetop'>QUOTE(ekpolk @ Sep 14 2006, 04:33 PM) [snapback]319790[/snapback]</div>

Quote:

Hmmm, it has cooled off substantially here in the last few days -- maybe that's keeping the engine just cool enough to prevent the transfer. Thanks for the info.
[/b]

Cool being a relative term in Florida. There are a few posts about problems, with this and maybe a TSB? I am not sure but do a search on the board and talk to your service folks.

Leo · 09-14-2006, 09:56 PM

<div class='quotetop'>QUOTE(Tideland Prius @ Sep 14 2006, 05:26 PM) [snapback]319736[/snapback]</div>

Quote:

It doesn't always run after you shut down. It'll only pump if the coolant in the engine is warmer (and above a set threshold) than the temperature of the coolant in the thermos.
[/b]

Are you saying there is always coolant in the thermos, even when the engine is full of coolant?

hdrygas · 09-14-2006, 10:53 PM

<div class='quotetop'>QUOTE(Leo @ Sep 14 2006, 06:56 PM) [snapback]319856[/snapback]</div>

Quote:

Are you saying there is always coolant in the thermos, even when the engine is full of coolant?
[/b]

Yes

**Tideland Prius** · 09-15-2006, 12:20 AM

<div class='quotetop'>QUOTE(Leo @ Sep 14 2006, 06:56 PM) [snapback]319856[/snapback]</div>

Quote:

Are you saying there is always coolant in the thermos, even when the engine is full of coolant?
[/b]

Yeah, it cycles through if needed, otherwise, it's blocked off.

09-14-2006, 12:25 PM	#1
ekpolk The Regenerator Join Date: Jul 2006 Location: Pensacola FL Posts: 363 My Car: 2004 Prius Model: Package: #9 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	OK, I've just finished getting used to all the fun little Prius quirks, such as the post-shut-down hum that is the coolant pump transferring the 3L of hot coolant into the insulated storage tank (a/k/a thermos). No problem with that; actually, it's sorta fun to explain to wide-eyed, envy-feeling friends, as I'm sure y'all understand. Then it stopped. That's right, a couple days ago, my car seems to have stopped transferring the hot coolant to the thermos. That pump is totally silent after shut down -- nothing at all, not even a gurgle. The coolant level is fine, both hot and cold, and I have no warning lights (so I assume it's throwing no codes, but I haven't had it plugged yet either), and no other noticeable symptoms (prolonged warm-up, etc) at all. Just no apparent filling of the thermos. Anyone got any thoughts on this? I'm not really worried, since otherwise the car is behaving fine, but still, I want to know what's up with this. TIA for any clues, suggestions, or solutions. __________________ ScanGauge-IIx for the TCH CAN View V3 (for when I care about maximizing Prius benefits). Valentine V1 (for when I *don't* care. . . ). Now in the TCH -- with Remote Display. Black 09 Camry Hybrid Cassis Pearl 07 Avalon XLS Black 04 Prius

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