jaswood

Obviously a sticking throttle/...cable.

Sorry, but this doesn't make sense! <_< I agree with CODE58. I have been working with Lexus for 14 years and Toyota for 6 years before that. I don't see how an oil pump affects oil consumption. But, then again, the service consultant doesn't usually know a whole lot about cars anyway. I'm sure the primary concern was the valve seals, not completely unusual, which seems to have been taken care of at the same time. I'm sorry to hear you had a scare with your Lexus, but I'm glad to hear your local dealership stood behind their product(something you wouldn't get anywhere else). The RX300 is one of the best cars we have ever produced and we try to promote an entire ownership experience. Good luck and enjoy your car! What if the oil pump pressure bypass fails...: OPEN: Not enough lubricant flow nor cooling. CLOSED: Pressure ALWAYS HIGH. I vote for open since closed will almost always "balloon" the filter. For one thing, the pump PUSHES, it doesn't "pull". I realize that it has to pull it out of the pan, but it's only doing that because the system is "primed". Second, where is the "oil pump pressure bypass"? There is a bypass in the filter, in case the filter gets clogged it won't stop the flow of oil and destroy the engine. But if the bypass is in bypass mode, I still wouldn't think it would flood the top of the engine such that it would cause such excessive oil consumption. Maybe it would. That Service Writers knowledge of (or ability to convey that knowledge in an understandable manner) is very typical of the service writers I had contact with in over 30 years in the automotive field (dealers). They are SALESMAN, which means the same thing it does in any field that uses salesman, mainly that they are good at spreading bull, and not very good at understanding what they're writing about. I seldom EVER got a service ticket that I didn't have to talk to the the writer for clarification and even then, you were never sure whether you were working on what the customer actually complained about or not. Oil pressure bypass is generally built right into the pump body. Some newer systems, 2010+, use a variable displacement engine lubricating oil pump in order to match pressure/flow to demand.

Why is it that we must always KILL the messenger...?? The knock sensors are sending you a message...LISTEN...!!

Both engine banks are knocking...??!!

Sorry, but this doesn't make sense! <_< I agree with CODE58. I have been working with Lexus for 14 years and Toyota for 6 years before that. I don't see how an oil pump affects oil consumption. But, then again, the service consultant doesn't usually know a whole lot about cars anyway. I'm sure the primary concern was the valve seals, not completely unusual, which seems to have been taken care of at the same time. I'm sorry to hear you had a scare with your Lexus, but I'm glad to hear your local dealership stood behind their product(something you wouldn't get anywhere else). The RX300 is one of the best cars we have ever produced and we try to promote an entire ownership experience. Good luck and enjoy your car! What if the oil pump pressure bypass fails...: OPEN: Not enough lubricant flow nor cooling. CLOSED: Pressure ALWAYS HIGH. I vote for open since closed will almost always "balloon" the filter.

Located the source for rear clunk upon quick re-acceleration. All three rubber bushing/cushions supporting the rear differential are shot. Ordered replacements via Amayama.com Anyone with experience with them...? 1995 LS400 w/250,000 miles.

No, cycling quickly on and off might very well be SOP depending on overall conditions. Besides which, what's the definition of "quickly"..?

Timing belt has "jumped" but only on one side.

I always manually switch the system back into footwell mode when the human comfort equation tilts to the heating side. There are 2 primary factors in providing human comfort, surrounding air temperature and sumation of radiant effects. Body "out-welling" IR radiation LOSS along with incoming radiation gain. In the wintertime the surrounding landscape will predominantly be COLD, giving your body the "shivers". Since the climate control cannot modify the body heat loss effects of that COLD landscape it compensates slightly by raising the cabin air temperature.

Simply a shame they didn't begin with the Toyota Venza as a Base, maybe even use the Venza's I4 but upgraded with Atkinson and DFI.

"..rear differential from an AWD.." REAR differential...? The first problem would be finding a '99 or '00(***) PTO, Power Take Off, that will mate up mechanically with the hybrid's CVT/PSD transaxle. *** '99 and '00 were the only RXes with a somewhat fucntional VC, Viscous Clutch, within the PTO. But then that, fucntional AWD, was part of the reason for so many premature transaxles failures for the '99 especially and to some extent for the '00. The 2010 and after are the only RXes with a decently functional "AWD" system. I keep hoping for a hybrid Venza but with its mechanical rear drive system. Maybe even with the Venza's new I4 but upgraded to DFI.

VSC defect..? Light and beep indication of VSC or TC activation, indicator light period is so short you don't really have time to look down, considering your attentiona is elsewhere, and confirm, but beep.... If VSC "thinks" the car is over-stearing to the right it will lightly brake the left front wheel. EDIT: Oops, sorry, you don't have TC/VSC...left front CV locking up momentarily..?

Accelerating, even slightly, into, in, the turn...? In that case you might be experiencing more torque stear than you remember now that you have renewed the transaxle to factory spec's. Torque stear will be more noticeable accelerating when turning in one direction vs the other, I don't remember which for the RX.

Front and back...?

On a HOT day the compressed refrigerant GAS cannot be quickly cooled enough to exit the condensor as a liquid so pressure builds and builds until the compressor clutch cycles off due to the high pressure.

Op said... "..when really hot outside..." That's when high side pressures will be at their greatest. Op might want to check and make sure the electric condensor/radiator cooling fan(s) are fully functional.

The very first thing I would do is remove, clean, and burnish the battery posts and connections. The engine/transaxle controlling ECU would then have to relearn the optimal engine/transaxle control parameters and now with a more SOLID 12 volt voltage source. If the problem continues then a new battery might be warrantied. The RX330 series makes use of DBW to lighten the stress on the transaxle during during power shifts so I wouldn't bother with doing the ATF changes unless the ATF odor or color is suspect. Also, the RX330 does not use a VC (lower driveline stress) so it does not "drive" the rear except under TC activation.

Tires, with age and miles, get noisier and NOISIER, especially it seems to me, beyong 8,000 to 10,000 miles. I have found that BridgeStone Turanza "SUMMER ONLY" tires have the lowest noise factor overall. It also doesn't hurt to remove the tires/wheels, pressure wash the ENTIRE interior of the wheelwell and then once FULLY dry discharge an entire can (NAPA, 3M) of rubberised undercoating into/onto each wheelwell, 2 coats. Also, keeping the window and door rubber seals "live" will help a lot, silicon spray or clear silicon or teflon grease is best.

"...is there a fix?.." Yes, lower the OAT.

SOP, high side pressure exceeds the safe limit as detected by the hi/lo pressure sensor.

IMMHO it would take a seriously high voltage, hi-pot "arc" level most likely, to do any damage to the oxygen sensor itself.

Why on earth would you ask a tire dealer to fix your A/C? You wouldn't ask an electrician to fix your plumbing. Most of those kids have a hard enough time replacing tires! The noise you're hearing is caused by a lack of oil in the compressor. May not be too late to save it. Surely, you have a Lexus dealer in your area. You may be surprised to find out that what you actually need is much less than you expected. Lexus dealer...? You're kidding, right..? No one should pay two prices for such simple work.

Why on earth would you ask a tire dealer to fix your A/C? You wouldn't ask an electrician to fix your plumbing. Most of those kids have a hard enough time replacing tires! The noise you're hearing is caused by a lack of oil in the compressor. May not be too late to save it. Surely, you have a Lexus dealer in your area. You may be surprised to find out that what you actually need is much less than you expected. Noise..? what noise, he doesn't make mention of any noise, just reporting a "drag" on the engine. Problem is more likely than otherwise a clogged idle air bypass port, A VERY COMMON problem with older cars, pre-DBW, having accrued >100,000 miles.

The majority of modern day, post 2000, vehicles that have high compression engines wherein premium fuel is RECOMMENDED will run on regular fuel just fine. The engine ECU simply uses the crank position sensor in conjunction with the new wide band knock/ping sensors to detect the fuel octane and then use the EFI system to enrich the mixture if the octane is too low for the compression level of the engine. Premium fuel is required ONLY to meet the manufacturer's performance specifications.

On what basis..? Pins 1 and 2 of driver's side sensor reads open, same pins on passenger side sensor reads ~14 ohms, shop manual calls for ~5-6 ohms at 70F. If the one sensor didn't read open I would probably ignore the 14 ohm reading as the engine ECU isn't complaining about that.