Hot Coolant Transfer Pump issues, part 2

jeromep · 12-05-2005, 04:30 AM

Some of you might recall a previous thread here that I started or contributed to regarding the hot coolant storage pump. I believe I started the thread before the most recent data loss here, so the original thread is gone.

In short, I have had a noisy hot coolant transfer pump for many months now, starting in the late spring or early summer. My car is garaged at home and at work, so my startups are in environs which aren't much colder than 60 or 70 degrees year round, maybe 50 degrees during the dead of winter. Well, predictably the pump would have a sandy or rough loud sound upon cold start up of the car, in the morning at the start of my commute and in the evening when I was leaving work. If I was running errands the pump would be much less noisy when starting up between shopping stops or whatnot.

Our weather has been pretty nasty for the past few days and I have opted to drive my old car to work and around. The roads have been covered with that deicing fluid and we have had some very slick roads. As such I don't want my nearly new car messed up by somebody that doesn't know how to drive in adverse conditions. That means the Prius has been sitting in my garaged for about 10 days with no use.

So, today I start it up, and I'm not realy paying attention, but I don't believe I heard the coolant pump do the startup transfer. Now, I'm not sure if that is because the car has been sitting for a while and there is no residual heat in the storage container, but I don't recall hearing the pump. I stop for gas and do not hear the pump at shutdown. After filling up I do not hear the pump do a transfer. I basically blow this off as the vehicle having moved hot coolant into the container using the main water pump while operating. I stop for dinner, again no pump and no pump on startup. I then go home and again no pump on shutdown.

Now, some have experienced a squealing pump which was replaced. But I'm experiencing no pump at all.

Considering how cold it is right now and the fact that I did drive many miles and the vehicle did turn off the ICE at lights and I had plenty of cabin heat. Would it be possible for the car to be making the transfer while I was driving and then not commanding the pump to do the transfer at shutdown or startup because the tank was already in the desired temp range? If the coolant in the tank has lost all of its heat energy, will the pump cycle anyway at startup or is it based on the tank having warmer coolant than the ICE at startup?

In general I found all of this behavior quite strange and I'm inclined to believe that I need to take the car in for the pump to be serviced, however I'd like this groups' opinions.

robinredbreast · 12-05-2005, 05:01 AM

I think I was the first to bring up this problem I had the exact symptoms as your pump . I had mine replaced in my 04 about 4 months ago so far everything is normal.

jeromep · 12-05-2005, 02:16 PM

Quote:

Originally posted by robinredbreast@Dec 5 2005, 03:01 AM
I think I was the first to bring up this problem I had the exact symptoms as your pump . I had mine replaced in my 04 about 4 months ago so far everything is normal.

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Credit where credit is due. Yes, you did bring this up earlier than I did. However, wasn't your squeeling loudly and it was replaced in that state and mine just seems to have siezed. Oh well, I guess it is a call into the service department I do not trust to get them to work on an issue I already tried to get them to solve prior to this point.

I'm not a happy camper.

Maybe I'll call Toyota customer service first and see if they don't roll out the red carpet for me on this issue rather than treating me like a bonehead.

**Tideland Prius** · 12-05-2005, 02:31 PM

Hmm, mine's developing that loud, high pitch sound. It comes on for a sec or two before reverting back to the normal pump sound. I'm taking it in on Tues.

With regards to the car not storing coolant, it's possible that it never got hot enough to warrant storage in the thermos. I believe coolant still cycles through the thermos during normal operation. I think someone else such as Dan can give a better, more detailed insight into this.

jeromep · 12-05-2005, 05:46 PM

Quote:

Originally posted by Tideland Prius@Dec 5 2005, 12:31 PM
Hmm, mine's developing that loud, high pitch sound. It comes on for a sec or two before reverting back to the normal pump sound. I'm taking it in on Tues.

With regards to the car not storing coolant, it's possible that it never got hot enough to warrant storage in the thermos. I believe coolant still cycles through the thermos during normal operation. I think someone else such as Dan can give a better, more detailed insight into this.

[snapback]168084[/snapback]

Thanks Tideland, I've thought about that. I was out driving around after I got finished with youth group last night trying to get the car warm, mostly for the purpose of testing out the thoughts you had above. The display indicated between 24 and 27F outside. So, below freezing, but not as cold as in the great white north at this same time. We are not used to these temps and them coming on so early in the year. This is the first Thanksgiving in many years where we have had snow and then a number of light snowfalls in the following days.

I'd like to think that I was out long enough for the car to either do the "running transfer" as you mentioned above, or for the system to turn on the pump at shutdown to cycle hot coolant into the tank. But, shouldn't the car have run the pump this morning when I started up. My car lives in an attached, but unheated, garage. I will estimate the overnight ambient temp in that garage at about 50 degrees. So, the car isn't in a freezing environment overnight, but every day this summer and spring and even fall when I went out to the garage after the car sat all night, it would run the pump at startup.

Any further thoughts from anyone? Please!

galaxee · 12-05-2005, 05:53 PM

average temps here are 40s to 50s and mine still runs the pump at startup and shutdown. i guess i don't do long trips (maybe 30 min tops in town here) but i don't think i've ever NOT heard the pump run afterward. this is my first winter with the car, but the temps and weather in general are about the same now as they were in march when we first got the car. i'd say it's time to take it in. it's still under warranty isn't it?

jeromep · 12-05-2005, 06:00 PM

Quote:

Originally posted by galaxee@Dec 5 2005, 03:53 PM
average temps here are 40s to 50s and mine still runs the pump at startup and shutdown. i guess i don't do long trips (maybe 30 min tops in town here) but i don't think i've ever NOT heard the pump run afterward. this is my first winter with the car, but the temps and weather in general are about the same now as they were in march when we first got the car. i'd say it's time to take it in. it's still under warranty isn't it?

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I appreciate your feedback, galaxee. Would you be willing to consult with your husband on this issue on my behalf?

galaxee · 12-05-2005, 06:08 PM

sure can, whenever he makes it home tonight

storm petrol · 12-05-2005, 06:08 PM

jeromep,

Just to add to the feedback, my pump runs every time that I power up or power down the car.

storm petrol

galaxee · 12-05-2005, 09:52 PM

welp, something's definitely wrong. the pump will always run at shutdown. unless, and this is the only case, there is no heat to store (aka the car was parked for a week, driven for 20 feet, and turned off)

he's seen a high resistance in the wire from the CHS pump to ground (about 50 ohms). this destroys the CHS pump relay, though it tests normally. this causes a problem with the pump running. he just reported it to tech assist today, actually.

given the noise, there may have been air in the system. this can burn out a pump. a simple test is to hook it up to at 12v source and check pump operation. if the system has been drained and refilled, the CHS tank is notoriously hard to bleed air out of.

hope that's helpful- sounds as though you definitely need to have that checked out.

12-05-2005, 04:30 AM	#1
jeromep Join Date: Dec 2004 Location: Eastern Washington State Posts: 821 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Some of you might recall a previous thread here that I started or contributed to regarding the hot coolant storage pump. I believe I started the thread before the most recent data loss here, so the original thread is gone. In short, I have had a noisy hot coolant transfer pump for many months now, starting in the late spring or early summer. My car is garaged at home and at work, so my startups are in environs which aren't much colder than 60 or 70 degrees year round, maybe 50 degrees during the dead of winter. Well, predictably the pump would have a sandy or rough loud sound upon cold start up of the car, in the morning at the start of my commute and in the evening when I was leaving work. If I was running errands the pump would be much less noisy when starting up between shopping stops or whatnot. Our weather has been pretty nasty for the past few days and I have opted to drive my old car to work and around. The roads have been covered with that deicing fluid and we have had some very slick roads. As such I don't want my nearly new car messed up by somebody that doesn't know how to drive in adverse conditions. That means the Prius has been sitting in my garaged for about 10 days with no use. So, today I start it up, and I'm not realy paying attention, but I don't believe I heard the coolant pump do the startup transfer. Now, I'm not sure if that is because the car has been sitting for a while and there is no residual heat in the storage container, but I don't recall hearing the pump. I stop for gas and do not hear the pump at shutdown. After filling up I do not hear the pump do a transfer. I basically blow this off as the vehicle having moved hot coolant into the container using the main water pump while operating. I stop for dinner, again no pump and no pump on startup. I then go home and again no pump on shutdown. Now, some have experienced a squealing pump which was replaced. But I'm experiencing no pump at all. Considering how cold it is right now and the fact that I did drive many miles and the vehicle did turn off the ICE at lights and I had plenty of cabin heat. Would it be possible for the car to be making the transfer while I was driving and then not commanding the pump to do the transfer at shutdown or startup because the tank was already in the desired temp range? If the coolant in the tank has lost all of its heat energy, will the pump cycle anyway at startup or is it based on the tank having warmer coolant than the ICE at startup? In general I found all of this behavior quite strange and I'm inclined to believe that I need to take the car in for the pump to be serviced, however I'd like this groups' opinions. __________________ It has been said: Hybrid drivers come in 3 flavors, greenie, techie and cheapie. Pick any 2. 2005 Prius, Millenium Silver over gray, package 5 (AI)

12-05-2005, 05:53 PM	#6
galaxee running WOT until out of fuel Join Date: Mar 2005 Location: central NC/ western WI Posts: 9,025 My Car: 2005 Prius Package: #5 Nominated 5 Times in 3 Posts TOTM Awards: 0 Friends: 20	average temps here are 40s to 50s and mine still runs the pump at startup and shutdown. i guess i don't do long trips (maybe 30 min tops in town here) but i don't think i've ever NOT heard the pump run afterward. this is my first winter with the car, but the temps and weather in general are about the same now as they were in march when we first got the car. i'd say it's time to take it in. it's still under warranty isn't it? __________________ black 2005 prius, tweaked just the way i like it my diagnostic guy on electronics: "lack of troubleshooting ability is due to a high common sense rejection ratio."

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12-05-2005, 05:01 AM	#2
robinredbreast Join Date: Sep 2004 Location: S.W Lower Michigan Posts: 42 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I think I was the first to bring up this problem I had the exact symptoms as your pump . I had mine replaced in my 04 about 4 months ago so far everything is normal.

12-05-2005, 02:31 PM	#4
Tideland Prius Super Moderator Join Date: Oct 2004 Location: Canada Posts: 13,755 My Car: 2005 Prius Package: B Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 11	Hmm, mine's developing that loud, high pitch sound. It comes on for a sec or two before reverting back to the normal pump sound. I'm taking it in on Tues. With regards to the car not storing coolant, it's possible that it never got hot enough to warrant storage in the thermos. I believe coolant still cycles through the thermos during normal operation. I think someone else such as Dan can give a better, more detailed insight into this.

12-05-2005, 06:08 PM	#8
galaxee running WOT until out of fuel Join Date: Mar 2005 Location: central NC/ western WI Posts: 9,025 My Car: 2005 Prius Package: #5 Nominated 5 Times in 3 Posts TOTM Awards: 0 Friends: 20	sure can, whenever he makes it home tonight

12-05-2005, 06:08 PM	#9
storm petrol Join Date: Jun 2005 Location: 44 degrees, 42 minutes North; 73 degrees, 29 minutes West. Posts: 62 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	jeromep, Just to add to the feedback, my pump runs every time that I power up or power down the car. storm petrol

12-05-2005, 09:52 PM	#10
galaxee running WOT until out of fuel Join Date: Mar 2005 Location: central NC/ western WI Posts: 9,025 My Car: 2005 Prius Package: #5 Nominated 5 Times in 3 Posts TOTM Awards: 0 Friends: 20	welp, something's definitely wrong. the pump will always run at shutdown. unless, and this is the only case, there is no heat to store (aka the car was parked for a week, driven for 20 feet, and turned off) he's seen a high resistance in the wire from the CHS pump to ground (about 50 ohms). this destroys the CHS pump relay, though it tests normally. this causes a problem with the pump running. he just reported it to tech assist today, actually. given the noise, there may have been air in the system. this can burn out a pump. a simple test is to hook it up to at 12v source and check pump operation. if the system has been drained and refilled, the CHS tank is notoriously hard to bleed air out of. hope that's helpful- sounds as though you definitely need to have that checked out.