wwest

Look at how many Lexus and Toyota vehicles already have the V6 DFI engine while the RX350 nor the RX400h do not. Everything in its time...

it's like a dog with a bone. . . . . . . . . .just won't let go.

Avoiding the infamous engine/transaxle downshift delay/hesitation. Higher octane allows the engine to operate in a Taller gear ratio at a low(er) RPM without "lugging", knock/ping. So with a higher octane when you initially re-apply pressure to the gas pedal shortly after/during the lift-throttle upshift the transaxle may (more often) remain, briefly, in the "taller" gear ratio since the ECU "knows" that will not result in a seriously detrimental level of Knock/Ping. The ECU would therefore allow the DBW system to immediately begin raising engine RPM, generating additional drive torque, as a result of the new, re-applied, gas pedal pressure. So now the engine RPM is no longer at idle and should you continue to increase the pressure on the gas pedal such that a downshift is required to keep the engine in a proper, non-lugging, operating range there is now much more likelihood that there will be be enough ATF pump pressure/flow volume to accommodate the upcoming downshift. The above might also be an indication that a fairly s..l...o....w re-application of pressure to the gas pedal after a FULL lift-throttle event might often alleviate the downshift delay/hesitation regardless of octane. Whereas a quick/fast/heavy re-application would almost always result in a serious level of knock/ping absent an immediate downshift. Counter-intuitive, huh..?? Go SLOW, to GO QUICKLY...!! Okay...??

Possible method of avoiding downshift delays... Higher octane allows the engine to operate in a Taller gear ratio at a low(er) RPM without "lugging", knock/ping. So with a higher octane when you initially re-apply pressure to the gas pedal shortly after/during the lift-throttle upshift the transaxle may (more often) remain, briefly, in the "taller" gear ratio since the ECU "knows" that will not result in a seriously detrimental level of Knock/Ping. The ECU would therefore allow the DBW system to immediately begin raising engine RPM, generating additional drive torque, as a result of the new, re-applied, gas pedal pressure. So now the engine RPM is no longer at idle and should you continue to increase the pressure on the gas pedal such that a downshift is required to keep the engine in a proper, non-lugging, operating range there is now much more likelihood that there will be be enough ATF pump pressure/flow volume to accommodate the upcoming downshift. The above might also be an indication that a fairly s..l...o....w re-application of pressure to the gas pedal after a FULL lift-throttle event might often alleviate the downshift delay/hesitation regardless of octane. Whereas a quick/fast/heavy re-application would almost always result in a serious level of knock/ping absent an immediate downshift. Counter-intuitive, huh..?? Go SLOW, to GO QUICKLY...!! Okay...??

Well, I'm 66, and while I would like the touchscreen controls, but after having used a portable Garmin, I will never again buy an embedded GPS/Nav system. The Garmin database and guidance system is head and shoulders above the 5.1 version in my 2001 RX300. and my right seat passenger can "reprogram' it at will, moving or no. Additionally it stuck me that the surround for the LS460 LCD screen was a bit too bright, almost chromish. And I can't help thinking "wouldn't it be nice if they built an LS460(299?) using the powerful V6 with FE DFI from the GS series". My 1992 LS400 only has 248 HP and that seems more than adequate. But then I get to drive a 2001 Porsche C4 if/whenever I need an injection of "the thrill of it all".

Huh?!? The "meat" of the bone is the marrow....

Bit into the marrow...?? Details.... At ~40k miles my 2001 AWD RX300's ATF was looking/smelled burned and appeared to be contaminated. I changed it out twice, 4 qts first time and 5 the second, after I discovered the second ATF drain plug in the diff'l case. Am now at ~60K miles and the ATF still looks mostly pristine. I became suspicious of the possibility of the VC heating to operational levels so I checked the condition of the gearcase oil in the transfer case and it looked okay, clear. I have always checked the ATF fill/condition at each DIY oil change and I don't remember taking note of any ATF problems/indications prior to the 40k mark. I'm beginning to wonder if I should revise my theory of the proposed sequence of events that led to all of these early transaxle failures and then engine/transaxle downshift delay/hesitation issues problems. Suppose... In about 99 Toyota and Lexus started using the FULL lift-throttle upshift sequence in order to A), improve FE, B), prevent engine compression braking from interfering with ABS activity, C), reduce the potential for loss of directional control due to engine compression braking, and D), any or all of the above. Apparently the ATF oil pressure pump in these earlier models did not have the capacity to provide enough pressure/flow for two gear changes in quick succession so these transaxles begin to fail due to the unexpected rate of clutch frictional surface wear from slippage. So the ATF oil pressure pump in the later models (2000, 2001 RX300??) had more pumping capacity. The problem that arises (arose?) from that fix is the fact that providing this extra volume/flow pump capacity with the engine at idle meant bypassing HUGE volumes of pressurized ATF at high engine RPM even when no volume, or very little volume, at all was/is required. Not only HIGHLY INEFFICIENT, but generates lots, TONS, of extra heat in the process. (Was the trailer towing package, including external ATF cooling heat exchanger, in my 2001 REALLY an option?) Overheated ATF resulting in the requirement that (thoroughly BOILED) ATF be changed out on a 15,000 mile schedule. So by 2004, the RX330, the lower capacity ATF pump was back in use and DBW was being used to delay engine torque development until the required downshift was completed. Note that the VC was also dropped for the entire RX330 run. Now I know why Ford has just announced they are using a variable displacement ATF pump in the new (FWD) Ford Edge "for improved transaxle operational efficiency". That would allow them to have HIGH volume/displacement capacity when gearshifts are commanded at low engine RPM, and proportionately lower volume/displacement depending on engine RPM at other gearshift times. And only enough volume to overcome system leakage and provide computing power (valve body) otherwise. Highly efficient and no requirement to use DBW to delay the onset of engine torque... Do you suppose Toyota is listening...?? Or given that the engine "flare" issue seems to have more recently come about has Toyota already begun to use a variable displacement ATF pump but the firmware is not yet been quite correctly "tuned" toward having enough volume, pumping capacity, at all the "correct" times. Does anyone have co-existence of the 3-4 shift engine flare problem and the engine/transaxle downshift delay/hesitation problem?

Details.... At ~40k miles my 2001 AWD RX300's ATF was looking/smelled burned and appeared to be contaminated. I changed it out twice, 4 qts first time and 5 the second, after I discovered the second ATF drain plug in the diff'l case. Am now at ~60K miles and the ATF still looks mostly pristine. I became suspecious of the possibility of the VC heating to operational levels so I checked the condition of the gearcase oil in the transfer case and it looked okay, clear. I have always checked the ATF fill/condition at each DIY oil change and I don't remember taking note of any ATF problems/indications prior to the 40k mark. I'm beginning to wonder if I should revise my proposed sequence of events that led to all of these early transaxle failures and then engine/transaxle downshift delay/hesitation issues problems. Suppose... In about 99 Toyota and Lexus started using the FULL lift-throttle upshift sequence in order to A), improve FE, B), prevent engine compression braking from interfering with ABS activity, C), reduce the potential for loss of directional control due to engine compression braking, and D), any or all of the above. The ATF oil pressure pump in these earlier models did not have the capacity to provide enough pressure/flow for two gear changes in quick sucession so these transaxle begin to fail due to the unexpected rate of clutch frictional surface wear from slippage. So the ATF oil pressure pump in the later models (2000, 2001 RX300??) had more pumping capacity. The problem that arises from that fix is the fact that providing this extra volume/flow pump capacity with the engine at idle meant bypassing HUGE volumes of pressurized ATF at high engine RPM even when no volume, or very little volume, at all was required. Not only HIGHLY INEFFICIENT, but generates lots, TONS, of extra heat in the process. (Was the trailer towing package, including external ATF cooling heat exchanger, in my 2001 REALLY an option?) Resulting in the requirement that (thoroughly BOILED) ATF be changed out on a 15,000 mile schedule. So by 2004, the RX330, the lower capacity ATF pump was back in use and DBW was being used to delay engine torque developement until the required downshift was completed. Note that the VC was also dropped for the entire RX330 run. Now I know why Ford has just announced they are using a variable displacement ATF pump in the new (FWD) Ford Edge "for improved transaxle operational efficiency". That would allow them to have HIGH volume/displacement capacity when gearshifts are commanded at low engine RPM, and proportionately lower volume/displacement depending on engine RPM at other gearshift times. And only enough volume to overcome system leakage and provide computing power (valve body) otherwise. Highly efficient and no requirement to use DBW to delay the onset of engine torque... Do you suppose Toyota is listening...??

My 92 Lexus LS400 has a hot water shutoff valve within the engine compartment, top-center of the firewall, that is completely closed when the system calls for max cooling. The valve is operated by a push/pull cable that comes through the firewall and is actuated by the same servomotor that operates the blend/remix door/vane. I noticed that in my 2001 AWD RX300 that valve is eliminated and so hot water always flows through the heat exchanger within the A/C plenum. So even with the blend door fully closed airflow coming to you via the climate control system (Max cool, A/C off, blower off, fresh inlet airflow) might be slightly elevated above OAT ambient. With the system set in anything other than max cool (max cool forces the blend/remix door/vane fully closed) the system outlet airflow might become significantly hotter that outside ambient. Your only other option is to go to Home Depot and buy a manual water shutoff valve to install in the hot water hose, the one with flow toward the heat exchanger, within the engine compartment.

When the engine is operating in O/D it is on the "cusp" of lugging, lowest possible RPM at which the engine power output is just on the verge of not being enough to move the vehicle forward at the current roadspeed (piston cannot move downward as fast as the flame front is expanding). So it makes sense that the engine ECU would now allow O/D gear ratio since it cannot reliably detect the onset of knocking/pinging.

Just thinking out loud. Why couldn't toyota use the DBW system to match engine RPM to current gear ratio/roadspeed upon FULL lift-throttle and thereby eliminate engine compression braking? Adverse effect on FE so probably not. Then again look how rare these instances seem to be, FULL lift-throttle coastdowns vs partial lift-throttle for entering cruising mode. If nothing else this technique could be used for the first few hundred milliseconds of FULL lift-throttle, thereby delaying the transaxle upshift, in case a quick return to acceleration is indicated. But then how would drivers react to the resulting engine RPM "flare" during FULL lift-throttle events? Worrisome.

Just thinking out loud. Why couldn't toyota use the DBW system to match engine RPM to current gear ratio/roadspeed upon FULL lift-throttle and thereby eliminate engine compression braking? Adverse effect on FE so probably not. Then again look how rare these instances seem to be, FULL lift-throttle coastdowns vs partial lift-throttle for entering cruising mode. If nothing else this technique could be used for the first few hundred milliseconds of FULL lift-throttle, thereby delaying the transaxle upshift, in case a quick return to acceleration is indicated. But then how would drivers react to the resulting engine RPM "flare" during FULL lift-throttle events? Worrisome.

Impossible to believe... Ford has the answer.....! From the new 2007 Ford Edge PR.. "<i>The electronically shift controlled transmission also features a variable displacement pump, which matches the amount of fluid that gets pushed through the transmission to driver demand, making it more efficient.</i>" At full lift-throttle all of the FWD Toyota/lexus vehicles begin an upshift just as the engine RPM drops to idle. With the engine at idle the upshift will exhaust/use most, or possibly all, of the pressurized ATF. Now if you happen to re-apply foot pressure to the accelerator pedal just as the upshift begins the engine/transaxle ECU will "know" to delay the onset of engine until the low engine "idle" RPM can build enough ATF pressure to complete the corresponding downshift. The most obvious answer would be to increase the volume of the fixed volume ATF pump so enough pressure/flow could be provided for two sequential QUICK shifts with the engine at idle. But then most of that added volume would be bypassed, disapated as heat, as the engine RPM rises above idle. Ford's answer, apparently, is to have a variable displacement ATF pump so it can be switched to high volume when quick/SOLID shifting is required with the engine at idle. Makes me wonder if that allowed them to eliminate the ATF pressure bypass relief spring/valve also. That would REALLY increase transaxle efficiency. A second option would havre been to have an ATF pressure storage accumulator (like the ABS pumpmotor asembly). But putting one of those in an already "crowded" six-speed transaxle is probably out of the question. Anyone know if any of the newer Toyota/Lexus transaxles have either? Absent one or the other the delay/hesitation issue will undoubtedly continue.

Impossible to believe... Ford has the answer.....! From the new 2007 Ford Edge PR.. "<i>The electronically shift controlled transmission also features a variable displacement pump, which matches the amount of fluid that gets pushed through the transmission to driver demand, making it more efficient.</i>" At full lift-throttle all of the FWD Toyota/lexus vehicles begin an upshift just as the engine RPM drops to idle. With the engine at idle the upshift will exhaust/use most, or possibly all, of the pressurized ATF. Now if you happen to re-apply foot pressure to the accelerator pedal just as the upshift begins the engine/transaxle ECU will "know" to delay the onset of engine until the low engine "idle" RPM can build enough ATF pressure to complete the corresponding downshift. The most obvious answer would be to increase the volume of the fixed volume ATF pump so enough pressure/flow could be provided for two sequential QUICK shifts with the engine at idle. But then most of that added volume would be bypassed, disapated as heat, as the engine RPM rises above idle. Ford's answer, apparently, is to have a variable displacement ATF pump so it can be switched to high volume when quick/SOLID shifting is required with the engine at idle. Makes me wonder if that allowed them to eliminate the ATF pressure bypass relief spring/valve also. That would REALLY increase transaxle efficiency. A second option would havre been to have an ATF pressure storage accumulator (like the ABS pumpmotor asembly). But putting one of those in an already "crowded" six-speed transaxle is probably out of the question. Anyone know if any of the newer Toyota/Lexus transaxles have either? Absent one or the other the delay/hesitation issue will undoubtedly continue.

Currently own a 1993 Ford Ranger PU with ~130,000 miles, a 1994 AWD Ford Aerostar with over 135,000 miles and a 2001 Thor Four Winds MH on a 1999 Ford E350 chasis w/77,000 miles. Other than normal, routine maintainance I have had no problems with any of those.

Hope you never need the warranty. If I should need the warranty I would hope that I am bright enough to reinstall the halfshafts prior to showing up at the dealer. But modern day vehicular relaibility, even a FORD, and my own DIY experience seems to indicate I would not have need of warranty service.

MY RWD 63 T-bird never had any problem "blasting" through snowdrifts back in MT winters, it was the stuff that was packed down or with an icy layer underneath that got my attention.

Do you advise I should go with the repair at the dealer or somewhere else? The dealer said it would cost 1100 to fix the motor There is no hot water shut-off valve in the 2001 RX. Assuming that you cannot moderate the cooling level except via blower speed or turning the A/C compressor off your problem is most likely the mixing vane/door servomotor that apportions cooled airflow through the water heater core. I'm pretty sure the mixing vane servomotor is accessible without disassembling anything. Passenger seatback fully reclined, upside-down with head into passenger footwell but.... Assuming it is the servomotor itself.

The clicking, specifically, is typically the result of some resistance in the electrical current flow path from the battery to the starter motor. I would remove the battery connections, clean and burnish the connections and the battery posts, reconnect and check the battery negative, ground, connection for tightness and the one at the starter solenoid. The problem could also be a weak or intermittent cell internal to the battery, if its more than 3 years old....

But hasn't the 2007 model been available since spring??

I NEVER liked the idea of FWD or front biased AWD and most certainly being restricted to the patently unsafe use of snow chains ONLY on the front wheels. So my 2001 AWD RX300 immediately got 1.5" wheel spacers all around so snow could be used at the rear initially and additionally at the front if it became necessary. I also upgraded to 17X8 wheels and the appropriate +1" tires. Wider tread = more traction and stearing "feel", >3" wider stance = more stabilty. I also switched to Bridgestone Turanza summer only tires for a more quiet and comfortable ride. Here in the eastside of the Seattle area I more often get to go to the snow and ice rather than it "coming" to me so I keep two sets of tire chains inthe RX during the winter months in case the latter occurs, and it has. Ahhh, the Lexus climate control "flaws" saga. I could fill a book. First, you need to know about at least three c-best options that are available that are set to stupidity "default" at the factory but that can be corrected by the dealer. Have the dealer set the c-best options such that the A/C can be indefinitely disabled simply by turning it off once. It will then remain off until you turn it back on. The second one is that the dealer can unlink the A/C from operating automatically, with no indication to you of same, in the defrost/defog/demist windshield "clearing" mode. The newest one, which I cannot say your 04 will have, is the ability to keep the system from automatically switching into "cooling" mode when your personal comfort level would be adversely affected. Insofar as the human comfort equation is concerned the heat gained/lost to the surrounding "landscape", your TOTAL surround, is just as important, maybe even moreso, as is the surrounding air temperature. While I cannot fault Toyota/Lexus for not having the capability to "sense" the the radiant effects of the surrounding landscape, no automotive system does, they could be a little less stupid about some aspects of the system. Say if the OAT is on the coolish side and the solar radiant sensor is dark. What the currently do, and insofar as I know have since 1989, is automatically switch the system into cooling mode during cool/cold weather when the IAT rises to within a few degrees of your temperature setpoint. If the human comfort equation "sum" happens to be on the "cool" side due to the lack of "incoming" radiant heating then you will be somewhat discomforted by the "coolish" and dry/dehumidified (provided you haven't disabled the A/C) aqirflow directed to your face and upper body. Additionally you might even find yourself EXTREMELY discomforted, as in 6 feet under, if this last aspect isn't "handled" properly. Assuming a rather cool or cold and somewhat humid climate (yes, a rarity) you may find the interior surface of the windshield quite thoroughly covered with condensation. Once the system switches, automatically to cooling mode absolutely NO warming airflow is provided to the windshield. So on a coolish or cold day the temperature of the interior surface of the windshield will begin to decline. If it doesn't reach the dewpoint of the cabin climate from that effect then just wait... For all of this time the A/C has been operating so as to dehumidify the incoming "fresh" airflow so as to prevent the dewpoint equation from becoming more serious. In that process the A/C cooling evaporator (10,000 sq. inches thereof) undoubtedly becomes covered with droppletts of condensation. as these dropplets grow in size gravity overcomes viscosity and they flow down and out the drain tube. But now as you drive along the OAT continues to decline and once it reaches ~35F the A/C is shut off automatically and cannot be restarted absent the temperature rising above ~35F. The A/C indicator do go off when that happened but with no aural indication to warn you of the upcoming DANGER. Next you begin to see small wisps of fog, condensation, at the bottom corners of the windshield, so just as any of us would, might, you reach over and activate the defrost/defog/demist function. BLAM........DAMN, what happened...??!! Your windshield just suddedly fogged over so thoroughly that you have NO forward vision. My $500 garmin has a much broader map database than the Lexus 5.1 I just paid $300 to upgrade to. And the Garmin has much better routing software to boot.

You mean a FWD or front Biased AWD vehicle? You're nothing if you're not amusing wwest. If I should buy the Mariner then both front halfshafts will be removed and discarded and the rear driveline clutch engaged full time.

There are several C-best options that can be changed by the dealer to help with this. First, the cooling mode airflow will be as much as 20F cooler than heating mode airflow. If you remember to keep the airflow in heating, footwell, mode you will undoubtedly be more comfortable. Later models, I don't remember when this started, have a c-best option so the system can be prevented from automatically switching to cooling mode once the cabin temperature rises to or near your temperature setpoint. This will also DEFINITELY help if you occassionally have windshield fogging problems while underway. Options on my 2001 RX300 are set so the operation of the A/C can be disabled indefinitely simply by turning it off once, and I also have the A/C unlinked from operating in either defrsot/defog/demist mode.

Yes, but like everything else, there are CHOICES/COMPROMISES to be made and being educated about your purchase options is a big part of that choice. For instance you will NEVER find me aboard a DC-9 nor any of its derevatives. I purchased a 2000 Lexus AWD RX300 well knowing it was actually more of a FWD than otherwise. It was a LEXUS. And here in the Seattle area I more often choose to go where there is snow and ice rather than have it come to me. So my 1994 AWD Ford Aerostar takes me to the snow and ice. I traded up to the 2001 RX300 model primarily to get HID and VSC/Trac. My next SUV purchase is very likely to be a 2007 Mercury Mariner Hybrid. We recently purchased a MH and so this can be a 4-down TOAD and replace the RX300 as a daily driver. If I wish I can remove and discard the Mercury's front halfshifts, engage the rear driveline full time, and have a RWD hybrid SUV. Of course I could do virtually the same thing with my 2001 RX300 or the new RX350 by modifying the PTO to open the solid front drive and then use the VC to couple in the front drive only with slippage at the rear. But that still wouldn't solve the 4-down TOAD problem.

I would imagine that the CLEAR MAJORITY of RX400h, and ALL others, that have driven on packed snow and/or ice have done so without any issues. Just as the CLEAR MAJORITY of commecial airline flights are completed with NO issues. Does that mean that the design engineers responsible for our personal safety should simply stop thinking about design improvements that provide additional safety features for the minority of drivers who might otherwise end up injured or even dead? NOT!