TunedRX300

Here is a good link on engine knock, read it and decide yourself. Gas Octane Few quotes "I THOUGHT GASOLINE WITH HIGHER OCTANE REDUCED ENGINE KNOCK? It did in older engines using carburetors to regulate air/gas mix They cannot as accurately regulate the air/fuel mix going into the engine as a computerized fuel injector. Carburetors need adjustment, as a part of regular maintenance, to keep the air/fuel mix as accurate as possible. So many times, these adjustments were not made regularly causing too much fuel to be mixed with the air. When this happened the gasoline would not burn completely soaking into carbon deposits. This would cause a premature ignition of the gasoline due to the intense heat in the engine cylinder creating "engine knock." When this happened, people would change to the higher octane/slower burning gasoline to resist the premature burn, thus minimizing the knocking problem. And it worked. Good solution. However, since the middle to late 80’s, engines are designed to use fuel injectors with computers to accurately control the air/fuel mix under all types of temperature and environment concerns. However the accuracy of the fuel injectors and computers is based on using the recommended gasoline for that engine. Most cars are designed to burn regular unleaded fuels with an octane rating of 87. If the vehicle needs a higher octane rating of 89-93, there is documentation in the owner’s manual, as well as possibly under the fuel gauge and by the fuel fill hole. Usually you will see this rating for high performance engines only. WHAT IF I PREFER TO USE GASOLINE WITH HIGHER OCTANE RATINGS? You can, but there are no real benefits, other than the gasoline manufacturers making more money off of you. When you use a fuel with a higher octane rating than your vehicle requires, you can send this unburned fuel into the emissions system. It can also collect in the catalytic converter. When you over stress any system, it can malfunction or not do what it was designed to do properly. In the early 90's, an early warning symptom was a rotten egg smell from the tailpipe. Easy fix, go back to using regular 87 octane gasoline. The rude odor usually disappears after several tanks of gasoline." Lexus recommends 87 octane, somehow many RX owners are compelled to use Toyota parts and follow Lexus recommendations but gas in a lone exception. Most ES and RX owners do not even know 87 is recommendated and assume by default 91/93 must be the recommendated fuel. Better performance does not mean $0.20 more per gallon at the pump and therefore there must be more HP gained.

check this thread out, you need to turn the rear wheel so that the fill plug is not blocked by nuts on the axel. R Differential Fluid Change

DIY is easy, need a small adjustable wrench in addition to 10mm socket with racket, costco has a good price on Optima RedTop if you go for that route Optima Redtop Autozone offers free battery installation if you buy the battery from them $50, just call your local store ahead and make sure they are not busy. Dealer will charge your twice and battery is not that great.

I heard PB blaster worked better than WD40 but I found the bigger problem is that drain plug does not have enough clearance to fit a open end wrench. I used a craftsman 15/16 open end wrench to loosen the drain plug. Claws from the wrench is too thick to latch on the plug completely so I patiently wedge in at an angle. Be careful not to strip the drain plug when you angle in and wedge the wrench onto the plug. After 5 minutes of playing and cursing Toyota, I managed to get a solid hold and get the drain plug off. Gear oil drained is darker than the rear - you must have a pump to fill - there is no little room to lift your fill bottle up.

WD40 helped me to get that fill plug loose, I used a L shaped 10mm Allen wrench. Lexus tighten it way too much. Also get yourself a hand pump to pump fresh gear oil in, should avoid unnecessary spills.

Must be air inside your brake lines I ran into the same issue when I upgrade to Legend Gen II calipers for my Acura TL. Use a Motive Power Bleeder - a one person bleeding pump. Let fluid out until you see no bubble out of bleeding valves.

RX300 has tranny cooler in front of passenger wheel well. It is also partially blocked by windshield wiper fluid reservior but I don't have a leak due to clamped hose design for five years. Rubber hose is great since I plan to install a in line tranny filter on the return line from the cooler - an excellent idea that SKperformance posted in the ES forum.

When powertrain warranty expires on my RX, I will switch to Amsoil ATF and add an external tranny filter on the return line from the cooler. The mesh just catch the bigger metal chunks. Magnets on two drain plugs are good to catch fine mtal debris but they works only on fluid nearby. Tranny Filter

If you buy OEM filter for better quality, take a look at the pic another member posted. Lexus install a better filter in factory (Made in Japan). The one that is sold at Toyota/Lexus is not as good (Made in Thailand). Guess which one has synthetic filter material, better anti-drainback rubber, and stronger inlet holes design?

No need to change spark plug until 120k. You should change your transmission fluid, buy 4 qts of Toyota Type IV do a drain and fill. It is easier than changing your own engine oil

I believe Toyota Type IV is synthetic. Use 10 mm Allen wrench to loosen the tranny drain plug on the driver side. It is facing down. Just behind it is drain plug for transfer case, also use 10 mm hex wrench to loosen. It is facing passenger side. Total drain is about 4 qts. Fill both through tranny dip stick hole.

A lot of people use front differential and transfer case interchangably. What one should do is to fill whatever is drained. After you jack up the car, use a 1/2" drive, 15/16 socket, an long extension, and a breaker bar or torque wrench to loosen the blue fill plug facing the rear. Catch any gear oil leaking out with an oil pan. Use an open end 15/16 wrench to loosen the yellow 15/16 drain plug facing down (it is just couple inches down from the blue fill plug). Be careful not to strip it because Toyota did not leave enough space to allow my Craftsman combination wrench to securely latch on - just patiently angle the wrench in until you can get a reasonable hold. That is why spray PB Blaster or WD-40 to soak up both plugs 10 minutes before starting is helpful. Last, use a hand pump to fill after draining out oil gear oil. I used Mobil 1 75w90 synthetic gear oil since it is not easy to do the front differential (that is what I call it) fluid change. Need to rotate rear wheel by hand to make enough room for a 10mm Allen wrench to loosen the rear differential fill plug.

Also check for a worn gasket where that manifold downpipe connect to the catalytic convertor.

As I stated, I am not interested in debating oil or filter material. Lexus determined/termed the sludge issue is due to "narrow coolant passage", I am not sure about you but that implies to me cooling is in sufficient in certain part of the engine by design. Lexus also does not require owner to change ATF, as specified in RX300's owner manual. RX owners are forced to change since they found out burned ATF or bad shift pattern during normal driving. The Thailand filter may work well in your LS400 but 1MZFE has a documented history of sludge problem, I would certainly want the same 90915-20004 filter which Lexus put into the RX as a factory install for replacement. If Lexus believe filtering material does not matter, they should not ask Denso to design 90915-20004 with synthetic filter material in the first place.

Transfer case has a separate drain plug facing the passenger side behind the tranny drain plug. Both can be opened with a 10mm Allen wrench. Fill up through the same tranny dip stick hole with Toyota Type IV ATF. Changing ATF

monarch, understand your wholehearted support of Toyota. If Toyota's design is perfect, we should not see RX's tranny having heat dissappation issue. Or engine issue discussed in this thread - sludge with 1MZFE. In fact I have never heard any automaker (American, German, Korean or Japanese) ever having engine oil gel up (owner's neglect or not) issue - only Toyota. Really don't want to start another debate on paper material vs synthetic fiber or dyno vs syn oil. I believe others have debated with you on this forum to supply data to support claims. I can find one Chinese made car that last 500,000 miles in certain parts but that example is a weak one if it is the only one out of millions of cars. Data and stats give us confidence on examples found.

Good luck trying to find one!!! Even the Lexus dealers don't have them. For my RX-330 I buy Toyota filter part number 90915-YZZD1. This is used in all Toy/Lex cars with the same engine. Cost about $4 / filter on-line.Check around for a Toyota cross reference part number for the filter on your RX-300. They are OEM Toyota filters and will work very well! ← Yes, few Lexus dealers carry those filters made in Japan. But I believe you can still special order them. Toyota does not make these filters, it outsource the design. Japanese is known for keeping best parts and designs for themselves. If Thailand filter is that great, why do RX300s factory-install ones made in Japan? I have an Acura TL and there is a big difference between oil filter made in Japan (Toyo Roki), in US, and in Canada (FRAM). Take a look of what is inside these OEM filters, not just the outside labels. Honda OEM filters Comparasion Unfortunately no one has done similiar for RX300 but there is a thread with pictures of outside looks side by side of Thailand vs Japan - at least we can see their external designs are different. OEM oil filter Thailand vs Japan This raises the question of why go OEM when Toyota/Honda is going aftermarket, worse yet, not offering the better product easily avaliable to the US?

Don't forget to get a good oil filter. If your oil filter is clogged and is bypassing all oil back to your engine unfiltered, it won't matter whether you put synethic or dyno oil. OEM filter definitely go for those made in Japan - not those made in Thailand. Aftermarket ones you need to research for one that has synthetic fiber with large filter area, high flow, and good anti-drainback valve.

There are about 16 qts of ATF in RX300 AWD's tranny, most is in torque converter. Drain & fill will replace only 4 qts, I would not mix Toyota T IV ATF w/ Mobil 1.

AWD has tranny cooler already, it is placed in front of the passenger front wheel and below the windshield fluid reservior. There are three ridge like holes on the plastic wheel well cover to let hot air escape - these holes do not exist on the driver side front wheel cover. Right hole from the front bumper serves as cool air inlet passage. But the circulation is terrible, not sure why Toyota choose not put cooler in front of the radiator. Here is a discussion on tranny filter. I will do it as soon as my warranty expire. Tranny Filter

Some Lexus dealer recommend a flush of brake fluid as part of 30K miles service. In Europe, I believe every car needs to pass brake fluid inspection every two years. To say that brake fluid last forever is wrong. There is no reputable source (DOT, SAE or automakers) makes that claim. Considering it only cost $10 to $20 per quartt, even with $60 of service cost, it is a safety measure that I would not skip.

wwest, I agree with your assessment on mechanics. Definitely DIY or find an experienced and trusted one to do all safety related works. But servicing brake flush is a different issue than claiming that it is not needed for the life of a car. I saw you skipped the following portion on Yahoo Auto. Again, if you have a web link to explain that water can not be absorbed when brake is not serviced, please post. 2. To remove moisture contamination. Brake fluid needs to be replaced periodically because DOT 3 and 4 brake fluids are glycol-based and absorb moisture over time. This occurs whether a vehicle is driven 30,000 miles a year or just sits in a garage because fluid contamination is a function of time and humidity rather than mileage. Moisture enters the system past seals and through microscopic pores in hoses. It also enters every time the fluid reservoir is opened (a good reason not to do so unnecessarily). After only a year of service, DOT 3 fluid may contain as much as 2% water. After 18 months, the level of contamination can be as high as 3%. And after several years of service, it's not unusual to find brake fluid that has soaked up as much as 7 to 8% water. Many vehicles that are six, seven or eight years old have never had the brake fluid changed! As the fluid soaks up moisture, it thickens and becomes less able to withstand heat and corrosion. The result is a significant drop in the fluid's boiling temperature, which may under the right conditions allow the fluid to boil in the calipers. Once brake fluid turns to vapor, the bubbles cause an increase in the distance the pedal must travel to apply the brakes. This condition should not be confused with "brake fade" that occurs when the brake linings get too hot as a result of prolonged braking. Brake fade requires greater and greater pedal effort to stop the vehicle while fluid boil increases pedal travel and makes the pedal feel soft or mushy. The danger of fluid boil is greatest in front-wheel drive cars because of the higher operating temperatures that are generated in today's downsized front brakes, and because the hydraulic system is split diagonally. Semi-metallic linings compound the heat problem by conducting heat from the rotors to the calipers. If the fluid contains a lot of moisture and can't take the heat, it'll probably boil. DOT 3 brake fluid, which has long been used in most domestic cars and light trucks, has a minimum dry boiling point of 401 degrees F. A 3% level of water contamination will lower this by 25% or 100 degrees! DOT 4 "extra heavy-duty" brake fluid, which is used in many European cars, has a higher dry boiling point of 446 degrees F. DOT 4 soaks up moisture at a slower rate than DOT 3 but suffers a greater drop in heat resistance as moisture builds up. Only 2% moisture in DOT 4 fluid will lower its boiling point by almost 50% or 200 degrees

I am not sure how a closed system with 100% liquid boiling into a mixture of gas and liquid can return to 100% liquid again. It is gas that can't escape and be turned back to liquid the problem. DOT has requirement on brake fluid to spec both dry boiling point (fresh fluid) and wet boiling point (fluid with water). Why does DOT require to let consumers know about wet boiling point, if brake fluid never get a chance to attract water? Here is another link that is provided by Yahoo. Brake Fluid by YahooAuto I respect that you have a strong opinion, but if you are so convicted that brake fluid never needed to be changed, please provide an URL from a reputable source. I am all ears to hear (actually read) about data and scientic reasoning.

There are parts of the braking system that is not built to endure high pressure. For example, RX300's brake fluid reservior is made from plastic and its lid can be opened easily by design. Yet the brake fluid in the reservior is circulated in brake lines and calipers so water does get into the system. Here is a quote from Stoptech's web site. Brake FAQ MYTH # 5 - BECAUSE THEY ARE NON-HYGROSCOPIC SILICONE BASED BRAKE FLUIDS ARE SUITABLE FOR USE IN HIGH PERFORMANCE CARS DOT 3 AND DOT 4 brake fluids are ether based and are hygroscopic in nature - i.e. they absorb water vapor. As the braking system in not quite airtight, a significant amount of water can be absorbed from the atmosphere in the course of a year. A 3% water content in brake fluid drops the boiling point as much as 170 degrees F. Brake fluid should be completely replaced annually. DOT 5 fluids are silicon based and are non-hygroscopic, which is good. They are also subject to frothing from high frequency vibration, which gives a soft pedal. Soft brake pedals may be OK in non-high performance cars (in fact, most drivers accept mushy brake pedals as normal) but they are not acceptable in any situation where the driver intends to modulate braking at high force values. MYTH # 4 - BOILED BRAKE FLUID WILL BE SERVICABLE AFTER IT COOLS. Once the brake fluid inside the caliper has boiled, it has lost a significant percentage of its original boiling point and should be replaced. It is not necessary to remove all of the fluid in the system, just bleed until clear fluid appears. MYTH # 3 - A SOFT BRAKE PEDAL IS THE RESULT OF PAD FADE The all too familiar mushy brake pedal is caused by overheated brake fluid, not overheated pads. Repeated heavy use of the brakes may lead to "brake fade". There are two distinct varieties of brake fade A, When the temperature at the interface between the pad and the rotor exceeds the thermal capacity of the pad, the pad loses friction capability due largely to out gassing of the binding agents in the pad compound. The brake pedal remains firm and solid but the car will not stop. The first indication is a distinctive and unpleasant smell which should serve as a warning to back off. B, When the fluid boils in the calipers air bubbles are formed. Since air is compressible, the brake pedal becomes soft and "mushy" and pedal travel increases. You can probably still stop the car by pumping the pedal but efficient modulation is gone. This is a gradual process with lots of warning.

You needs to replace your brake fluid every two years. Brake fluid attract water over time and lower its boiling point. When it boils you have air in RX's calipers and brake lines. Air is compressable and reduces braking effectiveness. I agree that RX's stock pads and rotor sizes are small compare to its weight. Just because SUV is not a sporty car there is no reason to design a weak braking system. When one needs to stop avoid an accident, bigger brake rotors, multiple pistons, and bigger brake pads save lives - does not matter what kind of car it is.