Hot Coolant Transfer Pump issues, part 2

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.

 

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. :angry:

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.

 

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!

 

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

 

Galaxee, you have been more helpful than you know.

The system has never been drained and refilled. This is the factory load of coolant. My prius is a year old on the 11th of this month, but I only have about 7900 miles on it. I'm not a heavy driver.

As to your reference about letting the car sit for a week and then drive it 20 feet and turn it off. The car did sit for at least 10 days while our weather was bad and I was driving the vehicle I don't really mind having a bozo run into. However, when I did fire up the Prius I drove it many miles (probably 30 in total) and ran errands, turning the car on and off. I had to go from my house to a shopping center with a Costco which is at least 10 miles away. Then 10 more miles to my parents house. Then after visiting with them back into town to do youth group, that is another 10 miles. And then I figure that the pump wasn't running when I was turning on or off the car and so after youth group I just drove a loop around town which then hit the interstate and back home, so another 10 miles. So that is closer to 40 miles. Anyway, The pump should have activated at any time during the startup or shutdowns that I encountered. The cabin got quite warm and was very comfortable, so I believe that there should have been a significant temperature differential, enough to get the pump to do the exchange.

Back to Tideland's earlier post. My pump sounded much liked your does now. It would be really noisy initially then it would quite down. Almost like it was pumping air. Which makes sens considering what galaxee has said about bleeding the system off.

Thanks all. I'm going to contact my dealer tomorrow morning and try to get the car in by Wednesday. I'll update. If any of you have any other ideas, I'll entertain them.

Unless anyone objects, I'm planning on printing this thread to show the dealer and the tech if I can get my hands on him.

 

That is the issue I was having. Noisy pump at cold startup in the morning. Usually it would start out noisy (sandy sounding, I'm making a leap here, but like it was pulling air) and then it would usually quiet down a little. Like robinredbrest, I could hear it over the radio. And this is what is really bothersom, I was getting this problem in late summer, beginning of September, and since my car is garaged it is protected from the full force of outside temperatures. Even in this weather the garage doesn't get much colder than 50 degress. If I went out to lunch from work the pump would sound mostly normal. I'm guessing that is because there was still lukewarm coolant in the block and that the coolant hadn't setteled or reached the lowest position in the system. And since I had warmed up the car at lunch the noise was diminished or non-existant when I drove home. Now I usually bring lunch to the office and that means the car sits for 9 hours unused. On those ocassions the pump would sound like it did in the morning.

I believe my original thread is gone, however Rick57 and I had some coversations and he stated that the pump sat on the bottom side of the reservior. Since the pump runs in one direction, into the thermos, and is at one of the lowest points in the vehicle, I'm a little confused as to how the pump could pump dry.

Tideland, since you are in SW BC does that mean you are west of the Cascades and have more of a Pacific climate or do you have more of an inland climate like I do being east of the Cascades?