hugo2648

When I switch on the ignition in my 2000 RX300, there is a buzzing noise coming from the transmission. Like a valve vibrating or a small motor running. You can hear the noise in the vehicle (engine not running). And the noise can be isolated to be coming from somewhere in the transmission by putting your ear close to the transmission pan.

The noise dissapears if you shift out of park (engine not running). It does not re-appear if you go back again to park. But if you take the ignition key out and then again turn on the ignition, the noise is heard again.

Is that normal ? What could be going wrong ?

rbtamms

That's normal Hugo, I already ask the maintenance guy at my dealer & he told me that the car is just recognizing the transponder pod in your key. Anyway, the sound always dissappear after a few seconds right?

hugo2648

No. Sound does not dissapear as long as the ignition is on.

It only dissapears if I move it from Park to Drive. And it does NOT come back when moving it back to Park. UNLESS I take the key out of the ignition and then again turn the ignition back on.

Note - Engine NOT running the entire time

I recently drained and refilled the transmission 3 times - each after 100 miles of driving - this was done to change as much of the transmission oil without flushing. I used Toyota T-IV oil

Meetya

That sound is from Pressure Regulator Solenoid (SLT Valve) in your transmission. That is normal. Just ignore it.

Lexmex

I also have that sound (for as long as I have owned my RX) and like Meetya said, quite normal. Sometimes it is a little louder (I noticed when the weather is cooler).