Hello, I am the happy new owner of a 2004 Prius. The car has 98,000 miles on it and as far as I can tell is running well. We're going to take a road trip in a couple weeks and I'm wondering if I should change the coolant and a very noisy coolant heat storage pump first? I've read in other posts that I should run the pump until it dies and I'm okay with that. But if it's prudent to change the coolant now then I'm thinking maybe I should do the pump as well. The engine and inverter pumps were replaced at 45,000 so I'm guessing the coolant has about 55,000 on it. And part of the reason I'm worried is we're going to Phoenix... Thanks for any advice!
The coolant is normally changed at 100,000 miles and every 50,000 miles after that, so I would say your ahead of the game. The heat storage pump only operates for a short period at start up and shut down. Even if it fails the car still drives without problems apart from the warning light. If this worries you then get the pump changed. Have all the recalls been done on the car? Your local dealer can tell you this as it may be that the inverter pump and coolant could be changed again along with a possible steering shaft. John (Britprius)
Please note. That pump is noisy from day one. It may not need to be changed. Also, as the 12 Volt gets weaker, it slows down and seems noisier. You may want to search Prius Chat for the 12volt battery test and make sure it is good BEFORE you take the trip. Good luck!
Hi John, Yes, all of the recall work has been done. My local dealer was nice enough to print out a full service history for me! Sounds like my coolant should last for a while longer - great! Thanks!
That is an excellent point. I'll look into it. I think the 12 volt battery is > 4 years old... Thanks!
Regarding the engine coolant change, I would suggest you wait until your return from your road trip because, even when you have the dealer do the service, it has been reported that sometimes air is left in the system. You would not want to discover that and try to get it fixed, the day before your road trip starts. Until the coolant heat recovery pump fails, there is no need to have it replaced since you cannot get it done under warranty - which has already expired since your car is 9+ years old. You have assumed that coolant was replaced when the engine/inverter coolant pumps were replaced earlier in the car's service history. That might not be a good assumption, especially with regards to the inverter pump - since it is quite feasible just to clamp off the hoses prior to removing them from the pump. Either way, the coolant should be replaced when your odometer reaches ~100K miles. To prep for your road trip, I suggest that you evaluate the condition of your tires and windshield wiper blades, as well as the 12V battery. Good luck.
Hi Patrick, You're right - I shouldn't assume the coolant was changed. I'll replace it after the trip. And I'm definitely going to look at the 12 volt battery. Thanks!
Hi Patrick, I tested my 12v the last couple of mornings using maintenance mode. In ACC mode with nothing on I get 12.1v In IG-ON mode with nothing on I get 11.9v In IG-ON mode with lights, fans etc on I get 10.8v Based on priuschat posts these numbers seem low. But at the same time they are mid-range according to elearnaid. If you were in my place what would you do? And does anybody know if the factory service manual talks about testing the 12v? And if so where? Thanks!
Hi Mike, I would say that your 12V battery is marginal and recommend that you replace it now. I am not aware that the factory repair manual offers any advice about how to test the battery.
I had a feeling you were going to say that. Alright I'll take the plunge. Definitely wouldn't want it to fail driving through the middle of nowhere CA/AZ. Thanks again!
