'Whoop' noise upon startup (1 Viewer)

[Mars06LC]

In the video you hear some rustling, the beep of me clicking the temperature adjuster, the blend door moving, and then a "whoo-ooop" noise.



Noise happens once every ~3 mornings in warm (70F/~20C) and cold (40F/~5C), while driving or in park, but always within 10sec-3min from starting. I believe it is coming from drivers side engine bay but I have never been outside the drivers seat when it occurs. There are no symptoms of the noise, no CELs, no abnormal behavior, etc. , it's just driving me crazy. Note: the secondary air injection system has been disabled so I don't think it's that unless the module failed (plus, the noise of a bad SAIS was a loud fan noise).

Anyone have any ideas?

 

[ramangain]

Your diithium crystal needs charging.

 

[IndroCruise]

In the video you hear some rustling, the beep of me clicking the temperature adjuster, the blend door moving, and then a "whoo-ooop" noise.



Noise happens once every ~3 mornings in warm (70F/~20C) and cold (40F/~5C), while driving or in park, but always within 10sec-3min from starting. I believe it is coming from drivers side engine bay but I have never been outside the drivers seat when it occurs. There are no symptoms of the noise, no CELs, no abnormal behavior, etc. , it's just driving me crazy. Note: the secondary air injection system has been disabled so I don't think it's that unless the module failed (plus, the noise of a bad SAIS was a loud fan noise).

Anyone have any ideas?

My similar experience way back in September 2013 was due to problems with the blend servo. A large Toyota/Lexus dealership in my part of the world familiar with LC100 Sahara and LX470 (both have the same 'climate control' system) said they knew all about the problems with the plastic gears stripping inside the blend servo buried deep behind the dash. They must have seen me coming for miles! After a bunch of parts were installed needing 10 hours of their labour (!), all is good and hopefully remains so for a long, long time.

Parts listed on my Invoice are:
87106-60100 SERVO SUB-ASSY, DAMPER, NO. 2 (maybe the FSM calls this the "air mix servo motor")
88578-50200 PACKING, COOLING UNIT, NO.2
88474-17010 DRYER, COOLER

Hopefully this is not your problem – it was a very expensive fix!

 

[Mars06LC]

My similar experience way back in September 2013 was due to problems with the blend servo. A large Toyota/Lexus dealership in my part of the world familiar with LC100 Sahara and LX470 (both have the same 'climate control' system) said they knew all about the problems with the plastic gears stripping inside the blend servo buried deep behind the dash. They must have seen me coming for miles! After a bunch of parts were installed needing 10 hours of their labour (!), all is good and hopefully remains so for a long, long time.

Parts listed on my Invoice are:
87106-60100 SERVO SUB-ASSY, DAMPER, NO. 2 (maybe the FSM calls this the "air mix servo motor")
88578-50200 PACKING, COOLING UNIT, NO.2
88474-17010 DRYER, COOLER

Hopefully this is not your problem – it was a very expensive fix!

View attachment 2473710

I don't think it's the blend servo. Blend door seems to operate fine and has the typical 'bzzz' noise, but nowhere as loud as the whoop noise in the video. Additionally, I think its coming from the engine bay.

Did your servo make a similar noise to the video or was it more of a grinding of gears?

 

[IndroCruise]

I don't think it's the blend servo. Blend door seems to operate fine and has the typical 'bzzz' noise, but nowhere as loud as the whoop noise in the video. Additionally, I think its coming from the engine bay.

Did your servo make a similar noise to the video or was it more of a grinding of gears?

In my case, no grinding noise (plastic gears), could describe it as ‘rustling’ or ‘fluttering’ as though a leaf was stuck somewhere and in addition a light "whoo-ooop" noise as though the flap or door could not decide what to do. I thought it was similar to your recorded clip – but my experience was 7 years ago so my reliability is questionable! In any case, if the problem relates to an aircon servo, it won’t happen with the aircon switched off, so I guess that may allow this possibility to be eliminated easily. Best wishes for the search!

 

[ramangain]

Besides the ubiquitous DL crystal diagnosis, it does sound like air being purged from somewhere. It reminds me of when the washer reservoir is filled to the cap level quickly.