Pump Noise Has Changed

Audrey -

Search this forum for "Coolant Transfer Pump". There are several informative postings related to these pumps becoming noisy over time.

My 2006 Prius coolant transfer pump went from making a normal "smooth running motor" sound to a making a loud erratic squeaking sound starting at about 18,000 miles. The squeaking noise grew louder and louder until I took the car in at 21,000 miles.

Since the noise only occurs at cold start-up and then only for a few moments It is apparently difficult for the mechanic to identify the source and diagnosed the problem. My dealer finally correctly diagnosed the problem as a bad coolant transfer pump and replaced it under warranty.

The replacement pump completely eliminated the squeaking sound. My car now has 30,000 miles and the squeaking noise has not returned.

 

My own pump sounds pretty horrendous in cold weather too, but still
appears to work fine ... if that's any comfort. Sometimes when it's
*really* cold it *doesn't* run at startup, which is somewhat
mysterious but was a decision made by the computer, not the pump
itself. Probably because the stored coolant has lost enough heat
so it's not all that useful, so I get a stone-cold startup anyways.
.
_H*

 

My coolant transfer pump started making a different noise right about the same mileage noted by the OP. Also, the weather got colder at the same time which has been noted as a factor by others.

It sounds like something out of a bad 50's sci fi movie. There is a recording that someone posted in another thread, and mine sounds exactly like his. Usually it only makes the sound on first startup after not driving for a few hours. I have heard it one time on shutdown, though.

I'm just going to keep an ear out for it for now.

 

<div class='quotetop'>QUOTE(ratlady @ Nov 13 2007, 08:58 AM) [snapback]538894[/snapback]</div>

Did they give you a price for replacement after it goes out of warranty? I am thinking of buying the Extended Warranty (~$990 for 7 yr/100K) to cover this repair and any others. You can buy the warranty any time prior to the expiration of the 3 yr/36K standard warranty.

 

<div class='quotetop'>QUOTE(ratlady @ Nov 13 2007, 10:58 AM) [snapback]538894[/snapback]</div>

Hmmm. I've been following threads on noisy coolant transfer pumps ever since mine started to make disturbing noises* about two months ago. I haven't read about anyone getting the sort of runaround you are getting. Could the way you were treated reflect your dealer's approach to warranty repairs rather than a corporate policy?

By way of contrast, I paid a visit to my dealership last week so they could listen to the noise. The service manager heard it, and immediately ordered a pump. I'm bring the car back tomorrow to have the new pump installed.


*Do a search for the file pump.wav. That's exactly how my car sounds when starting from cold.

 

<div class='quotetop'>QUOTE(JayGoldstein @ Nov 13 2007, 05:57 PM) [snapback]539104[/snapback]</div>

Couldn't find that file on PriusChat (also tried pump.wmv). But I'm pretty sure it's what I've been hearing lately. Have about 16K on the car and the weather got cool and it started making the noise after the car was turned off (and the engine relatively warm). I think I'll wait until the next oil change to bring it up with the dealer when the weather will be even colder (I'm about halfway thru the full warranty, so I have some time yet).

Thanks for helping me identify this problem!

 

<div class='quotetop'>QUOTE(nerfer @ Nov 13 2007, 06:15 PM) [snapback]539112[/snapback]</div>

The correct file name is pump-1.wav. Here it is:
[attachmentid=12461]

 

Maybe its Morse Code?

The pump is trying to communicate by Morse Code. :lol:

 

Okay, that's different from mine, and definitely sounds like shot
bearings. Wow.
.
N.b: when recording noises around the car, turn off things like
the A/C that would only interfere with the noise in question..
.
_H*

 

I should have given credit to biphnest, another forum member, for originally posting the .wav file. The thread is: http://priuschat.com/index.php?showtopic=38716&hl=pump

 

<div class='quotetop'>QUOTE(hobbit @ Nov 13 2007, 06:09 PM) [snapback]539152[/snapback]</div>

Yeah, that one does sound different than mine. Mine cuts in and out, but not that frequently, and is a bit higher pitched/louder than the normal pump action.

<div class='quotetop'>QUOTE(hobbit @ Nov 12 2007, 10:39 PM) [snapback]538723[/snapback]</div>

Wouldn't there still be coolant in the thermos that would be needed by the system, cold or not?

 

I'd argue that the pump is designed to:

1) pump coolant

2) run quietly.

If the pump stops pumping coolant then it has failed and should be replaced. If the pump starts running excessively loud then it has failed and should be replaced.

 

well, if the pump is indeed pumping coolant, then it's doing its job. ours tends to get louder when it's cold outside, but DH has done active tests on the thing and it works just fine. just a little noisier in the cold.

 

<div class='quotetop'>QUOTE(galaxee @ Nov 13 2007, 10:51 PM) [snapback]539283[/snapback]</div>

Can DH decipher the morse code signal that mine is sending? I think its saying "My bearings are bad, my bearings are bad" :lol:

 

Just hit 30K miles and now that it's relatively cooler in LA, my coolant pump has just started to make 'the noise'.

So much for the stealthy startup...