Buzzing Noise

[doitlast]

My es300 recently has a strange problem. When i stick the key in the ignition, there's a buzz noise coming out of the engine compartment ... more on the starter side. The noise continues until i take the key out. The position of the key doesn't seem to matter -- it's the same noise regardless of the position. The car starts and runs fine. Any thought? Thanks.

[kevinwang]

I have this too. I have no idea what it is but I don't think it is a problem..

[doitlast]

i removed the starter ... same noise still but shorter 5-6 seconds. Now the noise seems to come from the trans case or below it. I unplugged the speed sensor connection and the noise still there. Battery is old but good. The voltage shows up ok both when engine on and off.

A mechanic friend told me it might be the abs, is it??? How does the abs sound like? I mentioned earlier that this happens when i stick the key in the ignition -- no turning yet. What happens when the key is inserted? What stuff are powered on at this time? I've tried to listen for this noise on my other toyota-made cars but didn't hear anything. Any lexus gurus here?

[doitlast]

update: i put the starter back in. The noise takes longer to go away ~15 sec. It buzzes loud for 10-15 sec then become very low humm for another 5-10 sec then goes away completely after a relay clicks. When the noise is going, the voltage drop about 0.10V. Still suspecting some sort of short. The car drives ok as usual.

[George_Jetson]

when you first turn the key to the run position, there is a pump inside the abs unit that runs for a few seconds to build up hydraulic pressure in the accumulator. You can test to see if this is what you are hearing by removing the abs relay and then turning the key on. In you first post, you mention that is does not mater what position the key is in. Is this correct?

[doitlast]

when you first turn the key to the run position, there is a pump inside the abs unit that runs for a few seconds to build up hydraulic pressure in the accumulator. You can test to see if this is what you are hearing by removing the abs relay and then turning the key on. In you first post, you mention that is does not mater what position the key is in. Is this correct?

Yes, that's correct. The buzz is there when the key is in off position.

I've tested this some more and here's what I found: when the engine is cold ... like in the morning, the buzz is loud and prolong for minutes; when engine is hot, the sound is equally loud but just lasted a few seconds. The buzz/hum noise ends which a "tac tac" sound ... like a relay.

By the way, where is the ABS relay? I've replaced the front rotors on the car recently ... could it be related?

[George_Jetson]

the location depends on the year of your car, which you did not mention. I would suggest having someone put the key in the ignition while you look under the hood. Try to narrow down the location of the noise first.

[doitlast]

It's a 2000 es300. The noise comes from the air box side more towards the lower front of the car.

[George_Jetson]

Here is a picture of the abs relay, try pulling the abs motor relay and then see if you still have the noise.

[doitlast]

Thanks!

Update: i haven't pull the abs motor relay yet. However, if i operate the car regularly, the noise goes away. If I keep in parked for a few days then the noise comes back. Very weird... For now i'll keep driving it and see. There're some other higher priority problems with the car to tend first.