Recently our 2001 Lexus RX300 (AWD - 110,000 miles) has started to "whine" when the engine is started. The whine is getting louder and more pronounced. It is not clear whether the ambient temperature affects the "cold" noise level. In any case, the noise changes as the transmission shifts. After driving some distance, presumably after the engine/transmission warm, the whine decreases. There has been no affect on shifting, smoothness, or in the vehicle's performance. The transmission was serviced (flushed and new fluid at about 102,000 miles). The transmission fluid level is good.
My first thought was power steering pump so I listened under the hood. Checked PS fluid level - full. The noise doesn't seem to be coming from there. There is no change in the sound when the steering wheel is turned while parked. The noise seems highly correlated with the transmission shifting. Is there a pump in the transmission that would make noise if it where failing?
Any thoughts or ideas on this issue are greatly appreciated. Much obliged. Thanks.
