Lexus RX 300

trmga · October 2003

I have always had a problem with my 2001 RX 300 when refueling. On any gas pump the pump shuts off automatically when the tank is at least 3 gallons from being full. If I want to get it completely full I have to pump at the very slowest possible rate to keep the nozzle from cutting off. It takes about two or three minutes doing this after the auto shutoff activates in order to get a full tank. Some pumps will not pump slowly enough to do this and so I leave the gas station well short of a full tank. Anyone else experienced this problem?

bobfloyd · October 2003

I regularly have this problem of shut off before the tank is full on my 2000 RX 300.

wwest · October 2003

If you live north of the snowline, as I do, Seattle area, now would be a good time to think serious about disabling your A/C compressor. On my RX300 I simply unplug the refrigerant pressure sensor switch just in front of the radiator. In older models I always unplugged the A/C compressor clutch circuit.

WHY ???

Most modern day automotive A/C systems, most especially those of the automatic climate control variety, will automatically engage the A/C system to help dehumidify the incoming airstream (you wouldn't DARE be in recirulate at this point!).

At moderately cool outside temperatures, down to about 45F, this can often be a great advantage. But below these temperatures the efficiency of the A/C to dehumidify the incoming airstream declines precipetously, until at just above freezing, ~35F, there is NO dehumidification capability whatsoever.

With outside temperatures below 45F your system should never be in recirculate, and should ALWAYS remain in the mode wherein outlet airflow is significantly heated and routed through the footwell outlet ducts, with a portion bled off to the windshield defrost/defog/demist ducts. This latter air flow is there, by factory design, to help (hopefully) keep the interior of the windshield above dewpoint, the point at which condensation begins to form.

If you have a manually operated system then it will be up to you to remember to monitor the outside temperature and be sure the system has the proper airflow routing, footwell only, as the outside temperature declines.

If you happen to have one of the automatic climate control systems designed or manufactured by NipponDenso in Japan, or Denso USA, in the US, Toyota and Lexus for instance, it will be "biased" toward "cooling" mode (airflow outlet to the face and upper body) regardless of COLD outside temperatures and your personal discomfort due to radiant "cooling" from the COLD surrounding landscape.

Again, it will be up to you, as the driver and therefore "protector" of yourself and your passengers, to be extremely vigilent and ALWAYS over-ride the system from "automatic" outlet airflow control mode, to footwell and defrost/defog/demist mode manually when outside temperatures decline below 45F.

Now.

If the outside temperature is below 45F and IF the interior of your windshield beings to fog over, even ever so slightly, you need to take IMMEDIATE action.

1. Turn the temperature control all the way UP, to MAX HEAT.
2. Turn the system Blower all the way to MAXIMUM speed.
3. THEN....
Change the system outlet airflow mode to defrost/defog/demist.

So, why did this happen, why did the windshield start to fog over?

First, let's assume you followed the above instructions and the system was in heating mode, footwell and defrost/defog/demist airflow mode, and NOT IN RECIRCULATE!

At, say, 65MPH on a really cold day your windshield is being quite thoroughly chilled with the COLD airstream impinging on the outside at 65MPH even though there is a significant level of warming airflow from the system flowing its interior surface.

But now you just picked up two sweaty and wet snow skiers and you're headed back down the mountain. Or you were headed up to the slopes and your passengers became stressed out (sweating profusely) due to the ice and snow covered roadbed and the sometimes unavoidable side-slipping of the vehicle.

Moisture = higher humidity + a cool windshield surface = condensation.

Cracking a rear window slightly will almost always help move the cool dry air through the vehicle.

If you have not disabled your A/C for wintertime driving there may be yet another cause for the windshield fogging over.

Your A/C system was running but now isn't.

1. It may have shut down of it's own accord, automatically, a few moments ago, due to declining outside temperatures, 35F or below. Many modern systems will do this automatically, with no warning or obvious indication to the operator.

2. You may have just previosuly used the defrost/defog/demist mode, unaware that this mode automatically activates the A/C system to assist in dehumidification. Once you return the system to normal operation the A/C will shutdown provided you have used the control functionality to turn it off.

3. You may have just noticed that the temperatures have declined and manually turned off the useless A/C.

But why would any of these actions lead to windshield fogging to the point of being a real safety issue??

Long story, but first a short version.

When the A/C is operating it will almost always "gather" airborne water vapor onto the evaporator vanes. As more and more moisture accumulates it will eventually become dropletts large enough that gravity overcomes viscosity and then run down the face of the evaporator and out the drain provided for this purpose.

When the A/C compressor is first shut down the temperature of the evaporator surfaces will begin to rise. And remember ALL system inlet airflow, fresh and recirculated, comes through the evaporator. So that thin film of moisture, the film of moisture that had not yet gained enough mass to overcome viscosity, will begin to evaporate into the atmosphere within the passenger cabin.

BINGO!

Cold windshield, high atmospheric humidity.

The windshield begins to fog over!

Modern day exacerbating circumstances...

1. New, less efficient refrigerant.

With the advent of the use of the new less efficient refrigerants automotive designers were fored to come up with ways to make up for the loss of efficiency.

The most obvious way, and the one most often chosen, was to make the evaporator itsself a lot more efficient. The evaporator in my 1984 T-bird had about 2500 square inches of evaporator cooling surface. The one in the newer vehicles is more typically in the range of 10,000 square inches.

More evaporator surface area = more moisture left over to humidify the passenger cabin once the A/C is turned off.

2. Reduce the cabin atmosphere's "exhaust" outflow.

On a minute by minute basis, the less "conditioned" air that leaves the controlled environment the less incoming airflow that must be cooled.

3. Lower the system blower speed.

The slower the airflow moves through the evaporator vanes the more "heat" it gives up. A lower blower speed also results in even less exhaust outflow due to blower induced pressure differentials.

The Lexus car series is very well insulated for sound deadening and wind noise. MY 92 LS400, in fully automatic mode, could be using recirculate for 90% of the flow in the winter or summer, with the indicator light showing "fresh" mode.

JBaumgart · October 2003

Adjust temperature on Automatic Climate Control System to a comfortable setting. Use front and rear Defrost switches as necessary.

jeffmust2 · October 2003

...than darn windshield during the winter months and be done with it. Like the old Army Jeeps.

tidester · October 2003

Then how will you handle defogging those goggles that you'll need to protect your eyes? 8-)

tidester, host

lyv73 · October 2003

I've bought a 2000 RX300 from an Acura dealership in February. They offers free oil change there so I've been taking my RX300 there for the oil change. I think I need to have the brake rotors resurface since the steering wheel shakes pretty bad when I brake at high speed on the freeway. So just wondering if I it is better taking it to the Lexus dealership for service or would it be fine taking it to a Toyota dealership since it's about $100 cheaper? The question also post for regular maintenance schedules?

pschiffe · October 2003

Since the 50K warranty expired on my 99 RX, I've been taking it to a Toyota dealer for 5,000 mile service. About $100 cheaper than the Lexus store and no problems at all to date. They use genuine Toyota parts and I specify 5W30 oil as per Lexus recommendation. Only thing I don't get are the Lexus quick and dirty car wash, tire rotation or gourmet coffee. I have free lifetime tire rotation where I bought the Michelins (BJ's) so that is not an issue.

Pete

kwh · October 2003

Read posts 7719 & 7730 if you want to hear what has been going on with my wife's RX.

I called Lexus to see if they would now replace the front oxygen sensor under warrenty. The Service Manager said he would (he considered it an emmssions problem just like mikey said in 7722) so the warrenty goes to 60,000. He then said he would have to run codes off the check engine light in order to fix it under warrenty. He said he could not accept the Toyota service dept. "word" on this but had to verify this himself. I told him the light was out. I am now waiting for the celight to come back on.

When I called the Toyota place back the service mgr. said it would have been better if they had left the light on (apparently they have the option of leaving the light on or clearing the codes) but he felt sure the light should come back on in around a week. So right now I am waiting to see if the light will come back on. From what Lexus told me the light must be on to give them specific service codes, they can't just hook it up and get a readout - lesson learned by me I am passing on to all of you.

The Lexus dealer is 1 1/2 hours away and driving and getting service done becomes an all day affair, but this time I should have gone straight to the Lexus dealer. Toyota has been doing the majority of my service work and this is the first time I have had any problem. Any thoughts or suggestions, anyone?

wwest · October 2003

I can't remember for sure about the actual cost of a new oxy sensor for my 92 LS but I'm certain it was under $200 and took about 30 minutes, DIY, to replace.

erik_h · October 2003

My O2 sensor was like $450 and the dealer good-willed it to me for my 99 w/50K plus. I had to pay labor (< 80). I believe there are 4 O2 sensors according to clublexus. 2 near the motor and 2 further down the exhaust. Some are cheap, others are not. Mine was one of the more expensive ones.

cewe · October 2003

I am interested in buying 2000 RX300 with 35K miles (I live in New England). It has leather seats, moonroof, etc. It's in good condition with Lexus certified (3 yrs or 100,000 miles). The dealer requested $27,200 for the price. Is this a good price ? Please advise. Thanks

wwest · October 2003

Yesterday walking out of Lowe's an RX was setting there idling with DRLs on and I noticed they were almost completely sooted over.

Called the owner's attention to it and told her she should go to Lexus and have them replaced before she suddenly didn't have highbeams some dark night.

wwest · October 2003

News & views, Toyota/lexus AWD.

sorentocrazy22 · October 2003

I purchased a rx300 01 in may for a great price of 26,000. It has been a pleasure to drive because of its smooth performance and lush interior. I needed tires for the winter this week and used the advice from this site and bought Michelin 225/70/16 crosstrainers. They seem to be quiet and smooth just as everyone said, thanks for your help!!!!!

jiamin · October 2003

If I can Sacrifice a little performance but want the quietest tire, what brand and model would that be? TKS.

mikey00 · October 2003

My RX came from the factory with Bridgestone Dueler H/T's. I replaced them with Cross Terrains which were as least as quiet and had a more comfortable ride. The handling was much better. Tire Rack rates Cross Terrains at 8.9 for ride comfort and 8.7 for noise. LTX rates slightly below at 8.3 and 8.4. Integrity is at 6.7 for both. Bridgestone Dueler H/T is 6.9 and 6.2. My recommendation is go with the CTs, which is rated the quietest and the best performing.

jiamin · October 2003

for the info. By the way I forgot where I saw some tire shop let customer try new tires for free, for a limited time? Or is it from a particular brand?

brs1 · October 2003

Hi,
I am relying on my RX300 cabin air filtration
feature to protect my baby from breathing smoke
from current California fires. I think I should
change cabin air filter after driving in such a
heavy smoke. I have bought the filter from Lexus
already. Does anyone have any pointers how to
install it? There should be some tray in which
this filter sits, but I have no clue where is
that tray. User's manual is absolutely silent
about it.
Thanks a lot,
brs1.

jeffmust2 · October 2003

This filter sits behind your glove box's back wall. If you still can't find it, go back to Lexus where you bought the filter and ask the service writer to pop it in for you - takes about a half-minute if he/she is slow.

Take a good look at this filter - I doubt whether it's really helping all that much against smoke particles - nor is it meant to.

Consider the fact that most face masks that people use against smoke are ineffective and wrong; they don't filter out "particulate matter" to a fine enough degree.

The other designation for the proper filter material (beyond "particulate matter") is whether or not it's made for use in TB medical wards.

wwest · October 2003

The RX300 series filter is nothing more than a pollen and dirt particle filter. I don't know if the new RX330's filter will fit the RX300 "holder" but it is a more comprehensive filter, activated charcoal included, etc.

If it doesn't fit then try the following.

I go to home depot and buy the most expensive ($17) and largest 3M filtrete furnace filter and then use the material from it to make up to four RX300 filters. Make the "folds" tighter than they come originally.

kat2858 · October 2003

I'd like to replace the original GY Integrity tires on my '99 RX 300 AWD with the larger P235/70/16 Michelin Cross Terrain tires. Are there any clearance issues, problems or disadvantages to using the larger tire? Also, if the larger tires are used, is it necessary to replace the smaller spare if it will used only as a spare? Thanks in advance for any input.

mikey00 · October 2003

The 235 CTs fit fine without any clearance issues. The larger spare even fits in the well. And, yes, the spare should be the same size as the tires on the car. Some other points to know: The speedometer will be off with the larger tires, not much about 2%. Also, the 235 CTs only have a wear rating of 420, where the 225s have a wear rating of 700. That means a 225 should last 1.6 times as long as a 235.

wwest · October 2003

There is no reason to spend the extra money for the "correct" spare. My 01 RX was upgraded to 17x8 wheels/tires immediately upon purchase, about 30k miles ago. The OEM spare has only been out of its storage space for an annual pressure check and I expect it will remain that way.

Should I need to use the spare I don't expect to use it any longer than the time it takes to repair or replace a flat tire.

mikey00 · October 2003

Yes, I guess if you don't use it you could have just about anything in the spare tire well. I was thinking more of situations where you can't drive immediately to the repair shop, like my last flat on vacation.

wwest · October 2003

Is there any harm in driving 2 or 300 miles on the spare? Both the front and the rear diff'l are "open", free-wheeling.

brs1 · October 2003

Thanks wwest and jeffmust2 for advice on the filter.
I understood the limitations of the filtration system and was able to change the filter
(the original filter was more than 3 years old
anyway.)
brs1.

wwest · October 2003

I now owe engrbill a tall cold one or whatever his drink of choice might be. The C-best document he sent me does indicate that the A/C compressor can be "optioned" into strictly manual mode.

The first thing this morning I went over to Bellevue Lexus and the service manager reset my C-best options on my 01 RX300 so that the A/C compressor does not engage in the climate control's automatic mode nor even in the defrost/defog/demist mode. I can manually engage it in either mode if I wish to.

Normally a $47 charge by the service manager did it himself so it was free.

Sorta like finding the holy grail for me.

For three full winters and entering this one I have religiously disabled the A/C compressor in the 01 RX to prevent the unpredictable incidents of sudden windshield fogging.

Why is Lexus and Toyota so secretive about the C-best options?

The service manager was obviously reluctant to tell me of any other C-best options, and the floor salesman that I asked didn't even know what C-best was. Same thing at the Toyota dealership.

jeffmust2 · October 2003

Guess that CBest stuff's not in the manuals, eh?

LOL
LOL
LOL
LOL

Years of reading those posts...years we will never get back.

LOL
LOL
LOL
LOL

stever · October 2003

Nothing on Town Hall about C-best until this week.

There was a Lexus press release about it back in '99 - the text is so small I can't make it out what it says though.

Custom Features Make for Perfect Fit

Steve, Host

mikey00 · November 2003

I don't see any mechanical harm being done by using a different size tire for a few hundred miles. I was thinking more of a safety issue. Your handling will change, not to mention requirement of ABS, TRAC and VSC for same size tires. But then again, some will spend 40k for a "safe" car and compromise that safety by saving $100 on a tire. When you put that oddball size spare in the well nobody plans on using it more than a couple hundred miles but situations do arise.

wwest · November 2003

By 5%.........????

mikey00 · November 2003

I didn't do the math but that sounds about right.

craigcurry · November 2003

All these years I have been reading you post, I am amazed that you didn't know about CBest. I discovered it on this Town Hall some years ago. My disappointment was that the CBest could not disable DRLs in our RX300, however it could disable the DRLs in the LS. Go figure? Congratulations Willard.

stever · November 2003

And so it was; I searched yesterday for "c-best" and not much turned up. Searching for "cbest" found several posts - this looks to be one of the earliest RX300 ones:

grumb "Lexus RX300 Owners Forum - II" Jun 8, 2000 2:37am

Learn (or relearn) something new every day around here.

Steve, Host

wwest · November 2003

can be disabled by unplugging the voltage dropping resistor mounted under the battery support plate.

mlevinedc · November 2003

Hi all:

Does anyone have the TSB number or a web site url that would allow me to print out the TSB that applies to the brake rotors of a 2001 RX300? I've seen several references to the TSB throughout the life of the board and would like to bring something with me, preferably in writing, to the dealer tomorrow. As you might imagine, I'm having problems and a service writer that "never heard of it." Before I open a can of worms with Customer Service, I'd like to give them one more chance to make it right.

Mark

pschiffe · November 2003

I believe this edmunds.com location will link you the TSB numbers:

Edmunds Maintenance Guide

Pete

gsenthil · November 2003

I had a squealing noise from the brakes at 40k on my 2001 RX. Not sure if that was a worn pad or a TSB. Took it to the (Bellevue Lexus) dealership and told them about it and also asked if there was any TSB about it- and to change the pads on warranty if there was. My own research had told me the TSB was for 2000 and earlier only but I didnt see any harm in trying.

The result? The front pads were replaced out of warranty based on some TSB they found. I dont know what TSB they used- the part numbers changed are

04465-48060 Pad Kit Disc Bra
04945-33080 Shim Kit, Anti Sq
04947-48040 Fitting Kit, Disc

All the best

fickle · November 2003

I just got my car back today too (01 with 8,000 miles) and they fixed it under warranty for the squeaking brakes. It was the same parts that gsenthil listed. They replaced the front pads, supports, and shims. The TSB is BR001-02

They are also working on a steering wheel squeak. They've ordered a part #76082 Combi-switch. "Cleaned and lubed steering shaft at seal. Noise heard from steering angle sensor removed combi-switch and disassemble. Noise and rough operation felt from center/turning portion of combi-switch. Back ordered combi-switch #76082."

mooretorque · November 2003

The following is copied from the FAQ page for the RX300 on Club Lexus, by Daddy-O; the text attachment mentioned at the bottom did not make the trip, however.

What is C-Best and the C-Best settings for the RX 300?

C-BEST system stands for "Customized Body Electronics" System. It is a system that allows customization through the dealer's handheld tester with C-BEST cartridge installed.
The variables that are available for customization are as follows:

Wireless Door Lock Remote Control Wireless operation Yes* / No
Door ajar warning beeper Yes* / No
Automatic Lock operation 30s* / 60s
All door unlock (one press) On / Off*
All door unlock (2 presses) On* / Off
Panic Alert Operation On* / Off

Door Lock Control (Key)
All door unlock (key turn 1x) On / Off*
All door unlock (key turn 2x) On* / Off

Illuminated Entry Light Illum time 7.5s / 15s* / 30s
Interior lights illum on key unlock On* / Off
Automatic Lights Sensitivity -40%/-20%/0%*/+20%/+40%
Control logic switchover New(type 1)* / Prev (type 2)
Theft deterrent Passive arming On / Off*
Vehicle horn and security horn On* / Off
Entry delay time switch 0s / 14s* / 30s

Power window system
Key-linked open On* / Off
Key-linked close On* / Off

*denotes default factory setting

It takes the dealer about 10-15 minutes to change any or all items.
1. Connect meter to DLC3 port
2. Turn on ignition
3. Go to "Customize" menu to make selections. Most dealers do not charge for this service.
..............................................

Attached: A list of genearl C-Best options for multiple Lexus vehicles. It doesn't list which options work for which vehicle. I believe all of them work for the LS and GS and most for the RX, but not all.

View in Notepad with "Word Wrap" turned off.

Attachment: c-best options.txt

wwest · November 2003

Mooretorque...

I noticed over on CL that you're considering trading in the wife's RX for either an RX or a GX(??). Have you thought about waiting for the RX hybrid?

mlphilips · November 2003

I am looking at a 2000 Lexus RX 300 which has been well maintained but has 150,000 miles on it. I have verified the maintance with service records. My friends are telling me that I am crazy to even look at a car with that kind of milage, but I have a lot of faith in Toyota. I plan to have an different dealership look at the car to also give me an opinion. What do you think. Am I likely borrowing trouble, even if the car checks out.

I would appreciate any words of wisdom that you might have. It is a one owner car which was maintained by the Lexus dealership and I am would buy it from an individual.

jeffmust2 · November 2003

That's the highest-mileage RX300 I've heard of...say it's been on the road 4 years. Average miles would be 40000 to 60000. So in the best case, you have a vehicle with 90000 more miles than typical. I don't know what Edmunds used car guide would say about the negative charge for those miles, but let's say it's at least a dime a mile - that's minus $9000 from the normal used price and that would be in the area of $20k for a 2000 with typical options.

So...is the price around $10-11k out the door? If not, I'd certainly walk.

wwest · November 2003

MEANINGLESS.

I keep hearing stories of the 78-83 Porsche 911 SC series going 250k without motor work.

I suspect that's going to be the norm for Lexus once the vehicles get old enough for some of the fleet to get within that range.

Proper maintenance is the key.

jeffmust2 · November 2003

Mike -
Just checked Edmunds Used Car Appraiser and they are only deducting 3 cents a mile for those extra 90,000 miles - or $2,730 off the estimated selling price. They list a 2000 AWD RX300 with 150k and normal options at $19k sales price thru a private party. If your dealer is ANYWHERE near that figure - RUN! Run for your life.

jguo · November 2003

How much was the seller asking? I agree with Jeefmust2. Unless the price is less than $11k, it's not worth the risks, Lexus or not. There are plenty of good deals for RX300 with relative low mileage.

pschiffe · November 2003

Should have been changed at 90K miles and is almost due again!

Pete

mlphilips · November 2003

Thanks for all the good advice on the high milage Lexus. I typically drive about 6,500 miles a year and need something to putter around in. I also drive a car forever. However, I am not prepared to spend major bucks on repairs. The owner marked the car down from $15,000 to $12,500. I decided if it went at $10,000 I might bite and put some away for repairs. However, I passed on the car for now.

wwest · November 2003

If you're sure you're not going to purchase the high mileage RX would you mind passing the contact?

It occurs to me that it might be an excellent test mule for some of the patent application prototyping we're doing.

You can find me via strobedata.com

Lexus RX 300

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