wwest

Does the engine fault light illuminate with the ignition on but no engine start?

Well, first of all I didn't change out the factory "red" coolant in my 1992 LS400 until about two years ago, at about 90,000 miles. And I only did it then because while it was still pickish it was starting top look somewhat murky. Ph and freeze level were still within the proper range. I don't think my brother's 1992 LS400, now well over 100k, has had its coolant changed out even to this day. In my experience, dating back to the 1950's, the primary failure mode of automotive water pumps is the seal between the impeller/pump and the bearing. Once that seal gives 'way the bearing will begin to rust and failure will soon follow. There is a weep hole in the front of the water pump shaft extension so minor levels of moisture passing through the seal can get out and not cause the bearing to rust. It's a good item to check each time the oil is changed. I just installed a new alternator in a friends 1992 LS400 and rebuilt the power stearing pump. While there was stearing fluid leaking onto the alternator it turned out that that had nothing to do with its failure. I had purchased a new set of slip ring brushes for the alternator on the assumption that at more than 150,000 miles those would be toast. It turned out that the slip ring brushes had about 50% wear but the slip rings themselves were worn down to the metal shaft of the alternator. Time for a rebuilt alternator. So IMMHO these Lexus alternator failures are the result of inordinantly SOFT copper slip rings and have NOTHING to do with the power stearing pump leaking. So mine and my brother's LS400 can (slowly) leak all the power stearing fluid it wants and we plan to pay no attention unless the alternator fails. At that time we will likely rebuild the power stearing pump but still ignore the water pump unless the leakage rate indicates that its warranted.

Proposal for an aftermarket device to fix hesitation problems in all Toyota/Lexus 5-speed transaxles. Constantly monitor the gas pedal position via the OEM hall effect sensors. If/when the gas pedal returns to the "neutral' position check to see which gear the transaxle is currently in and automatically change the "shifter" electrical gear control contacts (there is no mechanical connection) to "command" a one-level downshift. If the brakes are applied simultaneously with the gas pedal being returned to neutral then "command" a downshift all the way into first. The vehicle will not downshift until the appropriate lower speed is reached. In both cases while the transaxle may not actually downshift due to roadspeed being too high it certainly would not upshift and later leave you waiting 2 to 3 seconds for it to downshift back into the most appropriate gear ratio for the acceleration level dictated by the new gas pedal position. If these were RWD vehicles I wouldn't hesitate to bring such a product to market but with FWD we would be incurring the liability that arises from FIRM engine compression braking on the front wheels.

The only reason FWD vehicles ever made it to public use is because they are so inexpensive to manufacture as opposed to RWD. Luckily the trend is currently and clearly going the other way. The AWD versions of the Lexus IS and GS will automatically apportion engine torque primarily to the rear if the VSC system detects, senses, via the yaw sensor, that the front tires' contact patch should be dedicated to maintaining lateral, directional control. The Volvo XC90 uses an AWD system that dynamically allocates engine torque. With the XC90 as you enter a turn/curve the engine torque is primarily routed to the rear and as you reach the apex of the curve it begins re-apportioning engine torque to the front. 99.99% of the time, for many of us, none of that matters. But since there is no way for the manufacturers to detect an approaching slippery surface it's that 0.01% that they are protecting you from. With the RX400h the front tires recieve 100% of the driving torque regardless, right up until you encounter that 0.01% roadbed condition. So in YOUR case as you approach the apex of that turn and the lateral stress on the front tires' is climbing rapidly the engine drive forces are additive to the lateral forces. And, yes, the instant one or both front tires' loose traction with the roadbed the rear motor will start producing drive torque. A REACTIVE system or a PRO-ACTIVE, AWD system, which would you rather drive? Do you ever wonder why the manufactuers didn't go to rear engine rear wheel drive back in the late 70's instead of FWD....? I certainly do. Maybe it was Nader's fault.

SWES, In all honesty if I won the lottery, or had the money, I would fund the developement of a high technology driving simulator so that beginning drivers could experience the dynamics of any and all cars before they go out and risk yours and my lives not knowing the proper reactions in the event they find themselves in dire circumstances. Why is it that we can afford to teach airline pilots how to perform in otherwise unexpected situations but not teach our own kids even the basic fundamentals. Not a drama queen, just heartfelt concern.

A few years ago I "fouled" one of these "centering" screws and went to Lexus to buy a new one. I was told that they are not a "stock" item because they are only used as a production aid, to hold the rotor in to place until the wheels are installed further down the line. After the wheels are on and properly torqued the rotors are "locked" into place. I ended up being given a free one since the shop mechanics never reinstall them when they do brake work.

By the book cover the end of a flat blade screwdriver with masking or duct tape so as not to scratch anything and pry the brake light cover up, carefully but firmly, with the screwdriver end.

I have been know to firmly block the wrench, disconnect the ignition and then use the starter....but I don't remember if that was to loosen or tighten.

Sorry Jay... Your advice is just simply wrong. When the A/C is operating the cooling vanes of the evaporator will be as low as 33F, and keep in mind that the evaporator is quite thoroughly buried (insulated!) within the A/C plenum where there will be virtually no convection airflow once the car is shut down. In point of fact 3 minutes may not be even enough time to exhaust the liquid refrigerant stored in the reservoir. Absent some device or modification the only solution I found is to leave the windows and or sunroof slightly open in the garage each and every night during the summer when the A/C is in use consistently. Year ago, 95?, I purchased a Lexus A/C evaporator, weighed it, dipped it in a bucket of water, weighed it again and then sat it out in the open air of a closed ~70F two bay garage. After two days its weight indicated that it still held over a pint of moisture on the surfaces. For many years my practice was to disconnect the A/C compressor clutch during the winter months. My 2001 RX300 has two c-best options that when set correctly by the dealer unlinks the A/C from the defrost/demist/defog mode, and allows me to disable the A/C indefinitely during the winter months.

"....occassionally accelerate....." I have noticed, as have many other owners, that the RX300 sometimes "feels" like it is accelerating ever so slightly. But what is actually happening is that the transaxle is upshifting. One of these times is just before coming to a full stop, the transaxle upshifts and the "feel" is somewhat like being bumped lightly from behind. The other time is during throttle fully closed coastdown circumstances at highway speeds. Here again, the transaxle will often upshift during coastdown giving the "slingshot effect" feeling. I have proposed that this upshifting is an effort by Toyota/Lexus to improve fuel economy slightly and also possibly to help prevent instances of loss of directional control on an icy roadbed as a result of engine compression braking on the front drive wheels. I have noticed that on an icy roadbed my ABS is at its most ACTIVE at extremely low speeds. Sometimes I feel as if the RX is never going to come to a full and complete stop in those circumstances. I know that many other manufacturers have taken what I consider extreme measures to alleviate engine compression braking on FWD vehicles, Cadillac even uses an over-running clutch, and mayb ethis is Toyota's effort in that regard. My ABS can moderate braking to prevent wheel lockup at low speeds, but it cannot overcome engine compression braking were it to exist. So I can understand why my RX might upshift just before coming to a full and complete stop and only shift down into first once fully stopped.

The last weekend in January you can watch as our 2 997 GT3's out run and outlast any Corvettes that show up.

Go to airsept.com and read up on their EED device. Or google for: demist nippondenso

Yes, the gas cap can/should only be removed for/during refueling. The gas tank and fuel system is kept under a slight vacuum to prevent fuel evaporation into the atmosphere. If the tank's fuel level rises when the vacuum is lost, filler cap is removed, the system ignores the event.

It appears that outside the US Lexus is dropping the ES series in favor of the IS. Notice that the ES is FWD, hardly appropreate for a luxury marque these days, while the IS is RWD. Not only that the IS is getting a new optional AWD system that automatically reapportions engine drive/drag (compression braking) away from the front wheels as the VSC's yaw sensor indicates lateral forces are building. Obviously a method of putting a higher priority on directional control than can any FWD or front bias AWD vehicle. Also keep in mind that the movement is to have more manufacturing in the US, the Camry and Camry hybrid for instance. Will the ES series then constitute a high enough production capacity requirement to keep the Japanese plant open. And if not will Lexus buyers accept an ES350 built in the US?

My first guess would be that you have a loose brake rotor or rotors. Applying the brakes would, for a short period thereafter, constrain the rotor "wobble", looseness, via the "squeeze" provided by the brake pads.

IMMHO what you describe is perfectly normal, and desireable, for the LS. My 1992 stearing was to "dead", no feedback, until I removed the damper, shock absorber, mounted on the stearing gear. I often have as opportunity to drive a 95 LS and it is even moreso as you describe.

That wobble may have very well "walked" your groved belt off of the other pulleys.

I wouldn't disagree, absolutely. But to be fair while my 2001 Porsche C4 NEVER goes out in those conditions intentionally I'b be willing to bet that on most adverse roadbed conditions it would outperform your RX400h, easily. My 78 SC Targa on the other hand..... On second thought the 78 has all the advatages of your RX400h, engine weight over the drive wheels. With the right, experienced driver, who knows.... To be fair many years ago I have had the 78 up and over the pass and back in the dead of winter with the roadbed snow packed. Also have driven hundreds of miles on icy roadbeds. But carefully, very carefully.

Becareful, very careful, of what you ask. I have no doubt that many 04 and later owners would gladly trade their engine hesitation problems for your clutch wear-out. Trying to sort the wheat from the chaff but currently it appears that the 2006 models are still being shipped with the engine/throttle hesitation problem. A premature transaxle failure trumps a bunch of totally random life threatening engine delay/hesitations EVERY time.

One of the pulleys msialigned or shaft retaining nut loose. It was the alternator pulley that did that to me.

Unless the lens or body is cracked somewhere the "pumping" action from cooling (lights off) and reheating will eventually, several days, drive the moisture out of the assembly. As the air heats due to the bulbs it expands and absorbs moisture. As the assembly cools it will draw in fresh air that is hopefully drier than that just forced out.

And lucky for me that is a VERY RARE event here in the great Pacific Northwest. But at those times I mostly drive the AWD RX300 and compensate for its front torque biasing by using tire chains at the rear. If I need to go to where the snow is, or likely to be, I have a 1994 AWD Ford Aerostar, also with tire chains on board but only for the rear, as backup. The only truly FWD we own is the 2003 Prius and my lead hardware engineer has permanent possession of that.

No, conclusion is really from reading up on the way the new AWD Lexus IS and GS dynamically reallocates engine drive/drag torque away from the front wheels when the VSC's yaw sensor indicates that the front contact patch must be used primarily for directional control. The IS and GS torque reallocation is pre-emptive and therefore more likely to be a "seamless", smooth transition. On the other hand the RX torque reallocation from front to back is purely reactive and therefore more likely to be quick, instantaneous, and disruptive to driving dynamics.

Again, if you turn the A/C off the heater efficiency will improve dramatically. But remember that the catalyst must still be kept at ~800F and in winter that's not going to be an easy task.

My "life at risk" statement was referring to the hazards of FWD or front torque biased AWD when driving on adverse roadbed conditions. The RX400h driving dynamics could be improved dramatically in these circumstances if they provided a manual mode "switch" (a "snow" switch??) through which the driver could change the primary drive and regeneration capability to the rear motor and thereby dedicate the front tires' contact patch entirely to directional control. They're already doing that, automatically, with the AWD models of the IS, GS and even with 4WD on the 4runner. With the AWD IS and GS if the VSC's yaw sensor indicates lateral forces are climbing beyond a certain level it begins reallocating engine drive/drag torque primarily to the rear. Can't find out much about the details of the 4runner, it simply says during "stearing" the engine drive/drag torque is removed from the front wheels.