Rx 300 Problems

[bradzap]

I am interested in purchasing a used RX300 for my wife. If anyone has information on common problems, concerns, or general “what to looks out for” I would greatly appreciate it.

Thanks

[SW03ES]

Two big things are the transmission and the concern of oil gelling. Make sure that whatever RX you buy has maintenance records that show oil changes every 5k and a transmission fluid change every 15k.

[RX in NC]

Spend some time perusing this forum and others like it and you'll soon realize that potential pitfalls involve transmission failure, oxygen sensor failure, exhaust manifold cracking, rear oil seal failure, and more rarely the engine oil gelling problem. Be aware that service at a Lexus dealership comes with premium pricing, so finding a good independent mechanic or being a do-it-yourself type of guy will greatly lessen the impact on your wallet if you decide to purchase one. My wife's meticulously-maintained 2000 RX300 has suffered from all of the above problems (all of which were repaired/replaced by the dealer at their expense) with the exception of engine gelling, and we won't be obtaining another one.

[wwest]

And if you buy into the above you are some one who needs to stay away from RXes entirely. The Letter I got from Lexus says nothing about oil changes or lack thereof being responsible for the gelling problem but it does say that a design change was made for subsequently manufactured engines to prevent the gelling problem.

Neither Toyota nor Lexus has ever indicated that anything more than the factory recommended 7500 miles oil change interval need be used.

The dealers though, are an entirely different issue, they want ALL of your money they can get, they'd be very glad to promote oil changes every 1000 miles if they thought it would "fly".

But regretably I must somewhat agree with the transmission fluid change out issue, but more like a 40,000 mile interval and then only if the fluid looks and/or smells slightly burned. As far as I can determine (numerous letters/ inquiries/responses to/from customer_satisfaction_inquiries@Lexus.com) Lexus is still standing by their recommendation that the factory installed transmssion fluid is good for the life of the vehicle.

At this point I very strongly suspect that the short, 40k miles, transmission fluid life some of us are experiencing has to do with the primary component of the AWD system, the virtually useless VC, Viscous clutch/coupling.

The amount of heat the VC generates is a function of how much or how often the front wheels turn at a different rate than the rear, tire chains on the front and not the rear just as Toyota and Lexus both mistakenly recommend, for instance.

But then the proper procedure, tire chains ONLY on the rear might still result in the VC causing over-heating of the transmission fluid.

[wwest]

bradzap.......of Michigan.

You might want to make sure you get an RX300 of a late enough MY that has some of the needed/desireable, in your COLD winter area, C-best setup options.

The Lexus automatic climate control system has some VERY serious design flaws. Flaws which were pointed out to them as early as 93 or before but which they chose to ignore until the 01 RX300 hit the market. And even today they are still experimenting with further improvements.

With the 01 RX300 you can have the dealer set c-best options such that the A/C compressor does not automatically operate in the system's fully automatic mode. The dealer can also set the system such that the A/C does not automatically operate in defrost/defog/demist mode.

On the 04 RX and later MY another important c-best option has been added. The system can be "set" such that the cabin warms toward and/or to the temperature setpoint the system remains in the footwell airflow outlet mode.

This can be extremely important since it is only in the footwell more taht the interior surface of the windshield is kept reasonably warmed.

If you allow the system to operate normally, switching to mixed or dash airflow outlets as the cabin temperature acclimates to your setpoint, ABSOLUTELY no system airflow will reach the windshield and therefore it becomes highly likely that it's surface temperature will decline to the atmospheric dewpoint and it will begin to fog over.

But, even ignoring the hazardous nature of the flawed climate control system. it's pretty discomforting to the front seat passengers to sit in an onrush of cool dry airflow when the radiant temperatures of the outside surrounding landscape is low enough to be chilling to the human metabolism.