1999 RX 300 Idle & Trans. Issues

Hi All,

Wondering if anyone out ther with this model has ever had a issue where your idle does not keep steady. Mine will be ok at time and from time to time when I come to a stop the idle jumps up and down from normal to below normal. Before I call the dealer and take it in only to find out that it may be something I could have fixed at home, can anyone tell me if they know of this. Also, no check engine light has come on due to this.

Second matter: from time to time when I initially engage my tranny into either Reverse or Drive it will clunk into gear, however, it shifts smooth once driving. At other times the tranny will engage normally (nice and smooth). Made an appointment at Lexus to have the tranny serviced with genuine Lexus tranny fluid and have the transfer case and rear axle level checked. The tranny oil is pretty clean, however, it was not serviced by Lexus the last time...about 17K miles ago. Anyone out there with similar issue and knows what the cause was.

Thanks

Briceno

Reply to
Briceno
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Hi, the idle problem is either the idle air control valve, or the throttle positioner sensor. If you get the check engine light, it will show a trouble code of P0120, which is the throttle positioner sensor. If no code, should be a dirty air control valve. Try cleaning it first. I had the same problem with my wife's Lexus. The hard engagement when you shift into gear is most likely the top engine motor mount, it looks like a dog bone, that should be your problem there.

Reply to
Wayne

Check the TPS.

If a scan tool is available, watch the CTP (Closed Throttle Position) value in the data list. It should read 'Closed' at idle w/ no throttle. If replaced, the value is relearned by the computer so the correct operation might happen until driven or reset.

Reply to
Bo Yancey

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