AISIN WQT-800 inverter pump failing within a year?

Just to be clear, the AISIN WQT-800 is not OEM. It is also possible that it is not a genuine AISIN WQT-800 either. Depending on where it was purchased, it could very well be a counterfeit.

Whether you replace it is up to you but it won't likely "rescue" your pump.

 

Do not know. I ordered a pump from the Toyota dealer 65k ago. Haven't had any problems.

Posted via the PriusChat mobile app.

 

Are you sure you're hearing that sound from the pump and not the coolant control valve, which is nearby the inverter coolant pump?

 

Are you sure it isn't pump cavitation? That is not only a pump killer, it can be a component kill as well. Usually caused by loss of cooling system pressure and dilution of the coolant allowing it to either boil because of temp, or because there is a restriction on the intake side dropping pressure and in turn, dropping the boiling point. Have you replaced the hoses on the suction side of the pump, they can suffer with being sucked in to the point they restrict flow, exaggerating the problem even further .......

T1 Terry

 

The CCV's common failure sound is similar to a top-loading washing machine agitating or an HDD constantly seeking (only much louder). There are quite a few posts in the Gen 2 forums where people have uploaded a sound file demonstrating the sound.

If that's the sound you hear, it is the CCV, not the ICWP.

 

AISIN is the OEM pump.


AISIN is the OEM pump.

 

It's possible for multiple things to be true at once, like (1) Aisin may be the manufacturer from whom Toyota obtains the pumps they sell, and (2) it would take substantial inside knowledge to find out whether the Aisin-branded WQT-800 is or isn't identical in all respects, QA acceptance thresholds, and so on (except for price, of course) to the units they supply to Toyota.

 

There is also the tolerance acceptability limit, below that level of manufacturing excellence, those that didn't make it are known as seconds, then there are levels of these seconds as to how far below spec they are, the buying price reflects this, so a 3rd level second may be cheap, but it is well below the primary buyers quality requirement.

Truely good manufacturers, don't sell their seconds, hey are immediately destroyed, right there at the testing phase, others cut their losses by selling their rejects ....

T1 Terry

 

In the late 1970's I worked some summers for a company which made, among other things, through hole component LEDs. There was a batch that failed QA. They had a temperature spec of something like -25 to 85 °C and they were not quite bright enough at the upper limit. So there was a big box of defective components which would eventually be sent to I have no idea where for disposal. There was a wink wink understanding that we could take a handful or two for our own hobbyist projects, we just couldn't resell them (or those projects with those components in them). This was long before the internet, I'm not sure how one would have gone about grey marketing them at the time. Ad in the PennySaver maybe?[/QUOTE]

 

The OP might want to use a mechanic's stethoscope to listen right on the pump and then elsewhere. I would suggest either unplugging the cooling fans by the radiator or pulling the fuse for them (if it doesn't disable something else) before trying this. The only other moving component is the belt for the mechanical water pump and that is pretty far away and so shouldn't be a safety hazard.