Fluid and Serpentine Belt Replacement, pumps too?

My 2008 Prius (176k) has been running loud lately, it seems to struggle to accelerate, and my mpg is lower than I feel it should (approx 40mpg). I don't expect an 11 year old model to have superior mpg, especially since I've not had much need to drive anywhere but local (short trips), and not every day. So a draining 12V to explain low power?

About 2 weeks ago I heard a loud sound coming from the engine on the passenger side of the car. I could hear it inside and outside of the car, and I determined that it was something to do with the AC. If the AC is on, the sound is there, and when it's off, the sound is gone. I pop open the hood to take a look and see that my inverter coolant is low. I drove about 25 miles home, and it sat (for a week) until I obtained SLLC then topped it off. The following day I drove 50 miles and it ran MUCH better, it wasn't as loud and it didn't seem to fight so hard to run/accelerate. I returned home the following day (another 50 miles), with 56mpg.

That seems great, but there's a reason that coolant was low and I need to find out what it is to stop it now. So, I start doing the research and learning all things coolant related, then begin to look for where the leak is, because I assumed it was a leak. I see no pink residue anywhere. I checked around all the hoses I could see, the serpentine belt, the radiator reservoir (sufficiently filled), I removed the radiator cap to find it also full*, and I could see no pink residue anywhere, so why was it low? Inverter pump failing? It runs, it's not loud, and there's movement in the inverter reservoir when it's on.

*First thing in the morning before starting the car. I've been checking daily, and no change.

I replaced the 12V in January, but pulled it, charged it, then took it to autozone to have it tested. It passed. My recent driving habits, letting it sit for a week, and a possible failing inverter pump are reason enough to take it in. New batteries die too, best to have it checked.

I added the coolant a week ago, and the car is running loud again. My fluid levels are fine (coolant, brake, oil, window washer fluid), and the car isn't, and hasn't been, throwing any codes (I made sure to run techstream before I removed the 12V).

I noted wear on my serpentine belt, so I ordered a replacement (OEM) and decided to see if there was any other maintenance that should be done so that I could take care of it all at the same time. Living in this forum for the last week has been an eye opening learning experience. I pulled the service record on the car (I'm the 2nd owner), and found that I've got some things to do.

As far as I can tell the ATF hasn't been changed, so I'll pick up ATF WS and replace that (I'll have it drain into a mesh strainer to check for metal). The ICE water pump was changed in 2011 (60k), and the Inverter Pump in 2013 (92k) - both note SLLC on the service record, and that the work was done under warranty. If the dealership replaced the coolant, then it's been about 84k since it was done and is overdue to be done again.

So I've got to replace the belt and fluids, but should I be replacing the pumps too? I've read a lot about changing the inverter pump as a preventative measure, and it seems like a good move. But what about the ICE water pump? I happened upon low inverter coolant when I popped the hood, but remember that I was investigating a sound that was in direct relation to the AC.

What causes the ICE to be loud? Anything related to the above mentioned? A separate problem? Either or?

As per the belt, I know it's BAD news if this thing breaks, and I've not changed one before, so I want to know if it'll be fine to make the 70 mile trip to the garage I'll be working out of? This one has been on the car for about 40k.

 

Is that something I'll be able to see once I get under the car?

Both pumps and coolant when I do the belt? May as well add one more fluid. Yes, I have tech stream. I wouldn't bleed this thing without it.

I've thought about a trickle charger, but my car isn't garage kept and there are no nearby power sources. I've not seen any that are rechargeable. Of course, marketing a rechargeable charger seems rather odd.

 

Good to know, thanks. I keep a booster pack in the car, in case of emergency.

Noted.

 

I successfully changed the oil and transaxle fluid, and after a great deal of issues the parts were changed out. However, the gasket on the thermostat didn't seal, possibly the engine coolant pump too. The nuts holding on the thermostat housing were so corroded, it took me over a day to get them off. I tried every trick I could think of, but it was the PB Blaster, that I didn't have with me, that did the trick. That, of course, required alternate transportation - which I had to wait for. Anyway, I finally got it in and spent a fair amount of time checking the seal as I never want to have to deal with this part again, and after I replaced the water pump and serpentine belt, it was time to refill the coolant. Which immediately spilled to the ground. I could see it coming from the thermostat plate and also near the water pump - though I'm not sure if that's run off from the plate or if I have developed a serious gasket handicap. Any tips or tricks that anyone might know about? Because right now, I'm just stuck (at my 'in-laws') and stupid (I'm really asking for gasket advice - this is a new low for me).

To add insult to injury, no sign of a leak when I removed the parts. Though I'm concerned that the coolant I drained from the CHS was red, and it was pink from the radiator and engine block. Anyone seen that before?

I haven't touched the inverter loop as I'm still waiting on the pump to arrive.

Edited to display Thermostat instead of Thermometer

 

Yes, I meant thermostat. I used all OEM parts, and proper torque specs. I thoroughly cleaned both, ensuring all of the PB Blaster was removed, I also waited until both were completely dry before continuing. I have RTV sealant on hand, but as you said - these are toyota parts and I shouldn't need to use it. Using sealant is only going to create a nightmare scenario should these need to be changed again.

I've already removed the plate from the thermostat, but not the rest. I had to walk away from it, but there are more storms on the way, and I'd really like it to be done soon.


My FIL equivalent has called a friend of his to come help, but he doesn't know about hybrids and I'm going to have to fight about the way you bleed this car. Maybe I'll be better off using the RTV to save myself the trouble of that battle.

 

Should I be concerned about the 2 colored coolants? I'm assuming that the red was LLC and that the coolant wasn't replaced with SLLC as indicated in the service history (which I was suspect of before I started the work), and that the pink was anything topped off after that. Though I added coolant to the inverter tank only, and I've not come across coolant draining 2 colors before, it's bizarre.

 

Ugh, so that means that whoever changed it last used some off brand. Brilliant. Oh well, it's getting SLLC now.

 

I have 2+ gallons on hand. I had 3, and I didn't use much to top off the inverter tank (which has maintained its level btw), but I don't know how much spilled through the failed seal. So it's likely that I'll have to pick up more since I'll be changing the inverter coolant as well.

I know how challenging/time consuming bleeding the coolant loop(s) can be, which is why I was worried about having a "long time mechanic" come take care of it. But, as it turned out, it was a needless worry. He was very kind and took the time to listen to me about the car, and he quickly figured it out. It was the right packaging, but the wrong thermostat, the seller is rectifying the error and the proper part will be here around the same time as the inverter pump, so I'll finish the job then.

I'm glad this was easily solved and grateful for everyone's help.

 

I seem to have a thermostat tragedy on my hands. The replacement arrived today, and when I opened the box I found a used thermostat. I'm returning it for a refund, but in the meantime I'm still without my car. I decided to test the old thermostat, to see if it was okay to put in while I await a 3rd replacement . It's not opening until the temp reaches 190°F, and as far as I'm concerned, it's toast. Now, my FIL equivalent informed me that he wouldn't trust the thermometer, and I'm going to get him a new one then re-test (I'm not going to install it, I'm just curious to see if there is a difference in the reading). Considering reinstalling the old one has me curious about how long the typical lifespan of a thermostat is, and whether or not a coolant change would be required when swapping it with a new one. Anyone know?

Also, if a new thermometer proves that this thermostat is shot, then what kind of damage could be done with it opening 10° higher than it should?

Can anyone suggest a reputable place to order one from? Preferably one that will deliver it swiftly.

 

I've received quality parts from them in the past, but I don't want an after market part. I've already experienced one that didn't fit, and it cost me a few days and an unknown amount of coolant.