Odd noise under Front upon startup and putting into gear

Maybe this is it...found it posted elsewhere on the web



The ABS self check occurs about 3-5 seconds after starting the engine IF the brake pedal is NOT depressed. If the brake pedal is depressed, the self check is then delayed until after the brake pedal is released. So if you are depressing the pedal (to put the vehicle in gear) prior to the "normal" self check after starting, the check does not occur until after releasing the brake and you have probably already started to move.

JASDMW...Start your vehicle, do not step on the brake pedal, and wait about 5 seconds you should hear the same noise you have been hearing...the ABS self check.

Interesting. I hear a "click" after putting it into reverse, and starting to move. I never noticed it when the van was new (though I also don't drive it much). I wonder if this is the same thing.

Mine is not a click but a sound something like DA...ZEEE.UH if that makes sense.

I hear the same (pumping type) brief sound but it occurs a second or two after I turn the key on, with or without starting the engine. It is coming from the engine, seemingly left of center (driver's side) ??? ???

CincyBob said:

I hear the same (pumping type) brief sound but it occurs a second or two after I turn the key on, with or without starting the engine. It is coming from the engine, seemingly left of center (driver's side) ??? ???

Click to expand...

Do you turn the key to "on" or to "accy"? If it's "on" but you haven't started it you may be hearing the fuel pump prime the fuel rails.

I think that is the ABS doing a precheck. It operates the ABS pump to make sure it is not locked up, at the same time it looks for an open or short in wheel speed sensors. Once you start moving it looks at the wheel speed sensors for rotation. I have not driven a newer model for a couple of weeks BUT when i do i will confirm this.

I have 2 Siennas, a '98 XLE (with towing package) and an '02 CE. I only recall hearing the sound on the '98.

Robo5 is right, the ABS is doing some sort of precheck. Actually the noise you hear is very similar to ABS pumping noise when its activated (when stopping on snow covered roads).

It will get activated after putting in D, after starting the car, about 1 sec. after the accelerator pedal is depressed when the vehicle starts to move.

At night, you can actually sense the pump consuming power since the headlights will dim when the pump is activated.

Topher said:

CincyBob said:

I hear the same (pumping type) brief sound but it occurs a second or two after I turn the key on, with or without starting the engine. It is coming from the engine, seemingly left of center (driver's side) ??? ???

Click to expand...

Do you turn the key to "on" or to "accy"? If it's "on" but you haven't started it you may be hearing the fuel pump prime the fuel rails.

Click to expand...

I think Topher may be onto something - I methodically/purposely turned the key to "acc" but did not start the engine(s), and heard the pumping sound (it lasts about 1 second) in both of my Siennas - "98" and "02".

Mine works as kchiew has described. I get the sound ONLY after I put the car into gear and begin movement.

Sorry to dig up an old thread!

I never heard the noise on my '04 until i read this thread.(and helped out) Now everytime i drive the van i hear it. It is not that loud on my van but it is there.

Thank you (?) ;D

...and I would like to join those who said it is sound of the ABS pre-check. This question/"problem" is typical in forums, thus, I remember answering it a number of times. Also, I remember that other system (VSC?) may try to perform its own pre-check, which sounds similarly. I just do not remember which system it is...

I own a 2005 Sienna. I notice a similar noise. It happens ONCE after start up , usually after the car starts to move. The movement may be forward or reverse. It sounds like "thud" or "click".
I do not remember hearing the noise when the car was new.I started to notice it at about 25k miles or so. I took the car to the dealer several times. The answers that I got from them , varied ...
don't know... I cant hear it... come back if it gets louder... maybe a brake problem...I think that it is your ABS readjusting..

Please note I have bought the 5 years extended warranty.. Hm mm???

At this point I tend to believe that it is the ABS readjusting.
I tried to set the key to " acc" ( as people suggested) I did not hear the noise.
Overall very frustrating!