Water Pump Question

i don't think we've seen enough water pump failures at your age and miles to bother

 

With the quality issues with pumps these days you may be trading in your original water pump that's more reliable for another pump that less reliable.

And because these water pumps are easy to replace if they fail... Just buy a spare pump and watch a you tube video on how to replace it and wait for an error code telling you the pump is bad before replacing it.

 

If you're thinking of possibly selling the Prius, I wouldn't bother changing out the pump. Mine had an error code at 214k miles. It was a over rotation code, it didn't actually fail. I went on Amazon and bought a new water pump rotor to replace the old unit. Yours at 120k miles should have plenty of life left (at least another 50k before you need to think about replacing it)

I didn't want to spend a lot on this engine as it's nearing the dreaded "need head gasket" mileage. So I refurbished the water pump with a new rotor and it should last until the engine needs a head gasket.

 

There has to be an explanation for the overrevving though. Often it happens when a part of the pump impeller has broken off so that it can spin faster because it's moving less water.

Another cause can be coolant so low it is spinning in air, which is also not ok.

It seems like Toyota added the P148F overrevving code in 2011; a 2010's water pump can have its impeller break like that and you don't get a code, because its ECM was never programmed to think spinning too fast could be a problem.

 

I did check the impeller fins and they were not broken. The thing I did notice was the thin plastic magnetic housing on the rotor was broken and somehow that made the impeller spin at an irregular speed.

The error that came up was simply the temperature symbol on my dash. It came up for about 10 seconds and it went off. That's the only indicator of the actual error, the car was driving normally. P148F came up and the rotation was about 800rpm faster than normal

My coolant was slightly low, maybe had to add 8oz a few months ago. I was worried that was a sign of head gasket failure but after adding the 8oz, the coolant has been stable.

 

Good example of growing pains for new technology... It's probably better than the older water pump tech, but at first it doesn't seem like it.

 

The "need head gasket" mileage is after 160k miles on a Turd gen car.

 

Just my opinion: with thorough/complete EGR cleaning every 50k miles, the answer may be never.

 

Just throwing in something a dealership mechanic told me a few years back - He actually did say to keep on top of the EGR system even if Toyota officially never really says to clean/replace it. But he also said that the water pumps are known to go without any warning around the 100,000 mile mark (give or take of course). At this dealer they worked on a lot of taxi/Uber/Lyft Priuses and that was almost always the issue they found. From that, I just replace mine around every 100,000 miles. I'm almost to 180,000 miles so will likely be replacing it soon to be proactive.

 

My daughter's 2013 with 169k mi started running a CHECK ENGINE light and intermittent TEMP light last week. Had low coolant in reservoir and had to show her WHERE it was. Topped it off.

Now this week, same things...topped it off and hooked up code scanner;
P148F Coolant Pump Over Revolutions
P0117 Coolant Temp Circuit Low Input
P261B Coolant Pump B Control Malfunction

After the top off and a 10mi drive, the coolant level was back down to half in reservoir, but TEMP light went off after turning AC off. Haven't noticed any leakage underneath or in driveway with reservoir cap on or off.

So am I looking at having to replace the Engine Coolant Pump?

 

The coolant will be disappearing somewhere. EGR and intake manifold ever cleaned? Any rough start-up after it’s sat overnight?

 

With those codes, definitely fix the pump problem.

"Fix the pump problem" won't always mean the pump itself is at fault; sometimes you'll want to rule out a wiring issue. But in this case, both P148F (revs too high) and P261B (revs too low) suggest there is power to the pump and tachometer feedback from it and the problem is pretty darned likely to be the pump itself. Likely enough I'd probably go ahead and change it without much other troubleshooting first.

The P0117 is scary. It means the temperature sensor resistance as seen by the ECM was so low the ECM thought it might be a bogus reading. The temperature sensor is a negative-temperature-coefficient thermistor (resistance goes down as temperature goes up), so bogus low input meant the temperature at the engine got so hot the ECM doubted the reading.

You don't want that to keep happening.

 

No drivability problem or start up problems. Haven't 'cleaned' EGR or intake manifold.

 

Happened to watch Mr B’s water pump replacement yesterday:

it’s a Lexus CT200, basically the same mechanics. His reason for changing: the pump’s propensity to fail, somewhere between 100k and 150k miles.

for me this is roughly $170 CDN, all-in with shipping:

Buy AISIN WPT190 Pump, Water. Prices, fast shipping, photos, weight - Amayama

 

anyone needing auto parts can enjoy 20% off their already discounted prices for July 4th Holiday. This special is good until July 8th.

Here is the link to the dealership I use online, free shipping for orders over $75 and they don't charge tax to out of state customers

Genuine Toyota Parts and Accessories: Official Online Store World Toyota

 

Even if I type in “water pump”, or “water pump assembly”, I get at least 22 pages, and the water pump ain’t on page one, it’s wandered off into everything but water pump. Toyota USA did a job on that parts site.

Have a direct link?

 

I just tried that search function for the site, it's absolutely awful. This might have to do with the cyberattack episode they had 2 weeks ago. Can't seem to find the right part with the search function.

This is the part that's needed

Electric Water Pump Assembly

Part Number: 161A0-29015 - It's $240.59 before the 20% discount and free shipping

 

$193.47 USD all-in. Amayama’s all-in price, converted to USD, at least at my locale, is ~$126. That’s with shipping, and with about 1/2 doz small purchases, never anything more, say tax, duty.

It’s the Aisin WPT-190, but I believe the same. They’ve never had anything bogus in my experience.