Help! Strange noise "Jill" with intermittent motor/fan turning on

New update: The "Jill" noise marks the starting of some motor/pump, about one second after the radiator fans come on. Location of the "Jill" noise is on the left hand side if I stand in front of the car and face the ICE. More details in post #11 below. Link here:
http://priuschat.com/forums/gen-ii-...rmittent-motor-fan-turning-2.html#post1100912

Newer update: It turned out that the A/C had been stuck at the ON state regardless of the A/C button setting. This complicated the troubleshooting. Now we know the "Jill" noise is associated with the starting of the A/C compressor. More details in post #14 below. Link here:
http://priuschat.com/forums/gen-ii-...rmittent-motor-fan-turning-2.html#post1101457

Even newer update: The A/C was probably not stuck on, just activated by the foot/defrost mode. More details in post #26:
http://priuschat.com/forums/gen-ii-...rmittent-motor-fan-turning-3.html#post1102348

 

Is this different from the brake actuator?

 

Thanks! Did you mean the coolant storage pump? Yes sometimes after the car off I hear its distinct "geeeeee...." sound for a few second and yesterday I also heard it and sounded same as before.

The intermittent motor/fan sound that came with one "Jill" noise sounded much smoother than the "geeeee...." sound.

 

In a PM Patrick Wong suggested that it may be the pump that circulates the engine coolant to the cabin air heater core if the heat was ON. Sorry earlier I only wrote "AC was not on" without more details which I have added in the original post (quoted above). I recently installed engine block heater but I don't see how a few extra cycles (when I turn the IGN ON to check coolant temperature with a ScanGauge, detail here: http://priuschat.com/forums/gen-ii-...block-heater-temperature-analysis-gen-ii.html) would break the pump.

I suppose I will try heat ON/OF and also try pressing on the brake a few times and see which one affect the noise. Any other suggestions? Thanks very much!

 

With the car OFF I pressed on the brake a few times and about every other time the brake accumulate pump came on and made the familiar "Badadadada" noise, without the strange "Jill" noise.

With the car READY and in park at the end of a trip (ICE was off), I heard the "Jill" noise twice, then I turned off the cabin air flow fan, it got very quiet and no "Jill" noise, then I turned the fan back on, the "Jill" noise came back. So this strange noise does seem related to the cabin air system.

I also tried to vary the temperature setting while stuck at stop and go traffic and the result is less clear cut. There seems to be more "Jill" noise events at higher T settings but I think there may be some at lower T settings also.

To isolate the problem further I need to be able to reliably control the pump for the heater core. Is there a temperature setting that guarantees the starting/stopping of the pump for the heater core? For example if I set it to "LOW" then the pump will never start and if "HIGH" then the pump always runs? Better yet, is there a relay somewhere I could jump and manually start the pump?

 

New observations from the end of trip today: I heard the "Jill" noise when car was still READY and parked, even though the cabin temperature was set at LOW (lowest setting) and fan was ON at lowest flow rate. I turned car off and opened the hood and turned the car ON.

With IGN ON (not READY), I turned the heat up and heard the heater core pump running. It was too quiet and different kind of sound compared to the motor/fan sound I heard yesterday, and no "Jill" noise at all.

I removed the plastic cover so I could see the radiator fans better, then I turned the car READY. The ICE turned on for some time and then shut off. Now the "Jill" noise (together with the intermittent motor/fan running) is back! I confirmed again that if I turn the cabin fan off, then no noise, if the cabin fan is on, then there is noise. The sound of the motor/fan running was much louder than any sound I heard when the car was ON (not READY) earlier.

Eventually I found the motor/fan noise was indeed the sound of the radiator fans. (Yesterday I mistook the fins on the fan housing as the fan blades. Duh!) Why the cabin fan ON/OFF affects the radiator fan ON/OFF is beyond me but this is so interesting to discover.

Finally the "Jill" noise is from the starting of another motor/pump running. This motor/pump would come on about one second after the radiator fans come on. I said "motor/pump" because the sound seems like a fluid pump but I may be wrong. The location of the noise seems to be on the left hand side when I stand in front of the car and face the ICE.

I have recorded the sounds and will upload to YouTube later. Done! Link here:

I merged three recordings (3 individual "Jill" noise events) together into one video clip.

Thanks very much for helping!

 

Thank you so much and hats off to you! You are right on the money!

Here is the long story: Today is a hot day and on the way home I found the cabin air coming out of the vents was quite cool even though I did not have the A/C on (both A/C and AUTO buttons on the Climate screen were off, fan and temperature were at low settings). I opened the window and found the outside air was definitely much warmer than the air coming out of the vents. Then I remembered that during the cold months there were a few times that, even though I had the heat on and the A/C off, I felt the air coming out of the vent was way too cold as if the A/C was actually on, but since the weather was cold so I couldn't be sure. When this happened I hit the A/C button on and off a few times but not much changed. Now with the hot weather I finally realized and verified that the A/C had been stuck at the ON state regardless of the A/C button setting during the last few months. So yesterday when I was doing the recording, even though both A/C and AUTO buttons on the Climate screen were off, the A/C compressor was actually cycling on and off, and each time it turned on it made the "Jill" noise. Now on the way home once I realized this situation, it occurred to me that even though hitting the A/C button on and off a few times did not unstick the A/C state, maybe switching between AUTO and Manual mode would. That's what I did and sure enough I was able to get warm air coming out of the vent after that, i.e. A/C now truly off. I just hope the ICE control or the brake control computer won't go crazy like the A/C control computer did on my car.

After I got home I did not hear the "Jill" noise with the car READY and in park (and the A/C truly off). I repeated yesterday's steps: turned the car off, then turned it back to READY, waited for the ICE to shut off, no "Jill" noise! Then I hit the A/C button on and off a few times, sure enough each time a "Jill" noise would precede the starting of the A/C compressor. :rockon:

Could other gen II Prius owners help listen to the A/C compressor turning on (with hood open) to confirm the absence of the "Jill" noise in a normal car? I need to be sure that this noise is abnormal before I talk to the dealer. Thanks very much!

 

Hi Patrick, You are right about checking the A/C button. It was off but as explained in the previous post the A/C control computer had gone crazy and the A/C compressor was cycling on and off even though both the A/C and the AUTO buttons were off.

The camera was indeed pointed at the radiator fan in front of the ICE and you can both see and hear the fan starting about one second before the "Jill" noise. I even put an arrow pointing to the fan in the first recording. (I just looked at the video again. I don't have my fast laptop with me. With my old desktop the video quality is reduced and it is harder to see the fan starting and even harder to synchronize the image and the sound.)

Yes I am disturbed that the A/C compressor starts to make this funny noise only about 1 year and 10 K miles.

 

Yes I knew the defrost mode will turn the A/C on but I wasn't using the defrost mode when all these happened.

Do you hear the strange "Jill" noise when your A/C starts to run (with the hood open will be easier to hear)?

 

Thanks! To be more specific, in the video there are
#1. Somewhat high pitched background noise of the IGN READY mode
#2. Radiator fan sound
#3. The "Jill" noise (about one second after #2.)
#4. A/C compressor sound (starting about half to one second after #3.)

The concern is on #3. When your A/C compressor comes on do you hear both #3 and #4 but not as loud or do you only hear #4?