Filehorse

I had two coils fail within about 1 year at nearly the same mileage as yours. I replaced the other 4 coils preemptively since I could see a pattern developing. I think the general consensus is that the coils on this vintage RX300 are not particularly robust and failure is not that uncommon. Since each coil is independent of the others I would not suspect any kind of external influence aside from age and heat. I hope you enjoyed the ride your mechanic took you on when he replaced all the plugs twice..!! A set of plugs should easily be good for 100,000+ miles unless there is something seriously wrong with the combustion process and anything that bad is almost certain to light up the Check Engine light. Caveat emptor.

Interestingly enough, there is an excellent chance that one or more of those P codes is causing your transmission to not shift into Overdrive. Twice I have had an ignition coil to fail which then causes the Check Engine light to appear. For the first 20-30 miles there was no problem aside from the reduced power and the rough idle with only 5 out of 6 cylinders firing. However, after that 20-30 mile period the transmission would refuse to shift into overdrive. If nothing else, it will force you to get it to dealer or a good independent shop to get the codes checked out. Once the coil(s) were replaced the codes cleared and the transmission once again resumed normal operation including Overdrive. This happened to me twice so I know it wasn't just an odd occurrence. I'd guess that once you get your known problems cleared up and the codes cleared, you'll find the drive system will magically resume normal Overdrive operation. As to long-term damage to the transmission operating it without overdrive, I'm sure some short time period of limited operation won't hurt anything but it's not something I would want to keep doing on a long-term basis. I'd be real careful about not getting this taken care of in the near term. I had my transmission rebuilt earlier this year for the trifling sum of $3200 and operating at a much higher RPM vs. road speed cannot be a good thing for a transmission that is a notoriously weak link anyway. Caveat emptor. Let us know what you find out.

I'd say you'll be good for another 100,000 miles.

The gospel according to NGK: NGK Spark Plug Recommendations The plug you pulled out is no longer available. There are multiple alternatives as shown in the chart from the link above.

If this is the original battery, that is the first place I'd look. Five years on an automotive battery is reasonable service and seven years is exceptional. The symptom you describe is compatible with those of a failing battery. The story your Lexus dealer told you should have begun with, "Once upon a time . . . . . ."

Good price on the servo.

If the aluminum water tubes to the heater core are getting hot as the motor warms up, the only thing that could prevent hot air from entering the cabin would be a mechanical blockage of some type. I suspect what you are seeing is only a partial movement of your old Air Mix servo and not full-range operation. That was what I was getting on mine. Unless there is a squirrel nest in the duct work, I think it has to be the Air Mix servo. I guess it is possible that the signal that controls the servo could be faulty but I've never heard of anyone having that particular problem without other symptoms. I'd suspect you might have display issues if that controller had failed but just guessing here. Given the age of the OEM servos and the known prevalence of this particular problem, I'm putting my money on success if you replace the servos. Be sure the servo is correctly connected to the linkage. It's pretty obvious but you can install it incorrectly. Don't ask me how I know.

That appears to be a ground wire of some flavor but I doubt it has anything to do with your check engine light. The Check Engine light is almost exclusively tied - in some manner - to the environmental controls on the engine. I had one come one a month ago and it turned out to be the Air/Fuel Ratio sensor. A failed oxygen sensor can also cause it as can a loose/cracked vacuum hose; faulty catalytic converter; failed engine coil; the list goes on. A lot of the Big Box parts stores (Auto Zone, Advance Auto, O'Reilly, etc.) will read the OBDII codes for you at no charge. A quick phone call will let you know which ones do or don't. Unlike proprietary engine codes which must be read by the dealer's analyzer, the OBDII codes are easy to read and very often the code will point directly at the source of the problem. The first step is to get the code(s) read to find out what you're dealing with. With a Lexus of this age and mileage, you should have found a good independent Lexus/Toyota shop who can do quality work for quite a bit less than your friendly Lexus Service Department but they probably won't include the freebie Otis Spunkmeyer muffins and Keurig coffee. Let us know what you find.

A roundup of the usual suspects would certainly include the Air Mix Servo. It sounds like your Air Mix Servo control has deteriorated to the point where it is all-or-nothing; i.e. Hot or Cold. Check this link for a discussion of issues and a reference to a replacement guide for the Air Mix Servo and the Mode Servo. Air Mix Servo Replacement Discussion If you're going to replace one servo you might as well replace them both since you have to remove the Mode Servo to get to the Air Mix Servo. If your Mode Servo hasn't started 'rattling' yet, it's just a matter of time. If you don't mind standing on your head under the glove box, this is really a fairly easy DIY although getting the Air Mix Servo mounting screws out can be a bit tricky. I just did all this on my 2000 RX300 AWD about two months ago. It was time well spent. Also, the link I have referenced also had an online reference for a place to purchase both servos for a LOT less than your local Lexus Parts Department typically will sell them to you. There is a lot of information available on this and other RX forums detailing exactly how to DIY this project. Lotsa luck.

In all probability, the geared nylon tail piece on the antenna mast has stripped or broken. It's a common occurrence on older vehicles. Here is a writeup that tells you everything you need to do to replace it as a DIY project. It really isn't difficult and if you have decent mechanical aptitude, this should be an easy fix. I've replaced mine as have many others. Here's the link I found on the forum searching on "RX300 antenna replace". There were other posts you might want to read for other info; perhaps some with pics. Here's the link: Antenna Mast Replacement Lotsa luck.

I'm going to go out on a limb here but most automotive multi-speed blowers have a speed controller that is essentially a series of resistors - usually located where the resistors or cooling fins are in the duct work. If you look here Blower Controller - Part No. 3 I suspect this is that device. If that is what this "controller" is I suspect it has failed. A quick check with your Lexus parts department can confirm if that is in fact what it is. Check the obvious things such as the fuses but your description of how it failed and the fact that a new blower does not work suggest the controller is probably the culprit. Others here may be able to provide a more definitive suggestion but this is where I would start. Let us know what you find. Lotsa luck.

I agree with your approach. If you are going to go to the trouble of removing the Air Mix Servo then I would replace it. After I replaced both of mine I did disassemble the servo and you can 'clean' the contact surfaces but I think the problem is more with wear than with dirt. I suspect any fix obtained by "cleaning" the servo could be short-lived and then you'd have to go through ALL this again to install the servo that you'll wish you had installed when you had it out the first time. Just go easy and use your good judgment on getting those screws out. It really isn't as hard as it looks but it could require a trip to the tool monger to get the right screwdriver and that would be money well-spent. Let us know how it goes.

If I remember correctly, the servo you are having trouble removing is the Air Mix servo. The easier one is the Mode Servo (floor, vent, defrost, mix). The air mix servo is the one that actually allows air to flow through the heater core and into the cabin. I was able to remove my Air Mix servo through the use of a thin screwdriver and probably a little "flexing" of the water supply/return pipes. It seems that I was "closer" to getting the screw driver head to engage more on one side of the pipe than the other so I approached from that side to flex the aluminum water pipe - CAREFULLY. The screws are seated in the plastic housing and don't require that much torque to loosen and once you get it started out it comes easily. Once I made the decision to "get it out or bust" the servo screws came out with little effort and there were no adverse effects (read: leaks) from flexing the aluminum water tubes as required. The tubes were not flexed sufficiently to impart a permanent bend; just a temporary displacement to allow the screwdriver to do what had to be done. NOTE: when the motor is warmed up, if you feel those aluminum tubes and they are HOT, in all probability the only source of your problem is the Air Mix servo. If you look at that servo and run the cabin temperature setpoint from Minimum to Maximum and there is little or no movement of the air mix servo positioning arm, the likely culprit is the air mix servo. Hope this helps. My advice is worth everything you're paying for it.

Although diagnosing sounds via a poor audio-quality video is difficult at best, that sound closely resembles the sound my 2000 RX300 AWD was making earlier this year and that was finally determined to be the center idler bearing on the timing belt. You need a mechanic's stethoscope to help locate the sound but that's where I'd start. If it's determined to be coming from the timing belt area and you plan to continue ownership of your RX, take the opportunity to replace the timing belt, idlers, water pump and valve cover gaskets since you'll already have removed most of the stuff necessary to perform those tasks and sooner or later, you'll have to do it anyway. Let us know what you find. This sounds like a job for a reliable Independent Lexus shop.

2000 RX300 Cooler Unit Part Numbers

A roundup of the usual suspects would include the Air Mix Servo. It's one of three servos located under the dash at the center console: (1) Air Mix Servo, (2) Mode Servo, (3) Air Recirculation Servo. The Air Mix Servo controls the amount of hot air entering the system to attain/maintain the set temperature. I just replaced my Air Mix Servo for the same reason and while I was in the area I also replaced the Mode Servo. You will find a lot of discussion/instructions/pictures on replacing these servos here: Servo Replacement Info. You will find discussions on how to disassemble and clean the servo contacts but that is only going to be a short-term fix. Your best bet is to just replace the Air Mix Servo. Even if the Mode Servo is working OK now, given the degree of difficulty to access these (actually, it's not THAT difficult) I would replace it while I was in the area. I ordered my servos from Stevnison Lexus, Frederick, Colorado (Servo Parts Listing). Their online price was a LOT less than what my local Lexus dealer quoted. I offered them the opportunity to match the price but they couldn't do it; they couldn't even get close!! Lotsa luck. Hope this helps.

Sounds are the most difficult thing to diagnose based solely on someone's description. As for the tires, I've thrown away at least one set of tires with only 15,000 miles on them because they were making the sound you describe. I hope you know a good independent shop who can help you diagnose what you're hearing. Oh, and the CV joint would probably not be on my roundup of the usual suspects but a wheel bearing could be. The pulsing sound you hear at low speeds can morph into roar and be masked by other sounds at highway speeds so don't discount that possibility. I'd still start with the tires and be looking for unusual and/or uneven wear patterns - often on the inside or outside grooves of the tire. You may need to swap some tires to see if the problem changes.

If the tires are getting old that can cause the sound you describe. It can also be caused by a failing wheel bearing. I had a similar issue with my RX300 and it turned out to be the tires. Replaced the tires and it was again as quiet as a church mouse. You also can't rule out a failing CV joint but with the limited information available, I'd be looking at tires first and then wheel bearings. Regardless, it "sounds" like you need to get it up on a rack where someone can do a real inspection.

What price piece of mind?? If the Air Conditioner, transmission, or engine have any significant failures during the 3-year warranty period, that $1,260 commitment would be recovered with room to spare. That said, statistically you will never get your money back. I've got 166,000 miles on my 2000 RX300 and I didn't have that kind of failure until the transmission failed about 5,000 miles ago and for this transmission I was overdue. Lexus knows the failure rates for the high-dollar components and if the people with the green eye shades thought - statistically - that your repair costs would exceed that $1,260, you would NOT be getting a 3-year extended warranty for that price. At 72,000 miles you are long past the 'infant mortality' failures typically attributed to poor workmanship or components. What you're looking at now are end-of-life failures which should occur well north of 125,000 miles. I'm guessing this 3-year warranty also has a mileage component and is not an unlimited mileage contract. For what it's worth, I think you really need to decide if that 3-years peace of mind is really worth $1,260 considering that the odds of you getting it back are really quite slim. Will some people who buy that warranty be glad the did? Absolutely. Will most people who buy that warranty be glad they did. Absolutely not. Lexus has worked the bugs out of the high-dollar components/systems in the 12 or so years the RX has been in production. The days of engine sludge and premature planetary gear failures are pretty much history. Assuming you change the oil every 5,000 miles, service the transmission at reasonable intervals and treat the vehicle with the respect it deserves, I think you're better off to just escrow that $35/month against the day you do have a repair that would have been covered by the warranty. I also think you'll have money in the bank at the end of the 3-year warranty period. Of course, your mileage may vary.

I 2nd Lenore's comment; the RX300 AWD goes quite nicely in the snow with decent All Weather tires. It has no "Low Lock" so don't be out trying to follow any Hummers over the rivers and through the woods. Most of the power does go to the front wheels but there is plenty of traction to get you up and over most any hills on roadways in the snow.

I'm guessing this will require a trip to your local Lexus dealer. If the "key" were easily available at the local Auto Parts Store, there wouldn't be much security involved. If you can't locate the key somewhere in the spare tire well or in one of the "hidden" storage compartments in the back, I'd be going to wherever I had them rotated last and having them look for it. I would hope they might have a "Lost and Found" box for stuff that comes out of customer vehicles but never gets put back in. As for my RX300, I took the locking nuts off, replaced them with matching lug nuts, and put them in a baggie in the rear tire well. There must be a couple of million RX300s out there and I don't think these wheels are big theft items - at least not in my neck of the woods. Lotsa luck.

At this point, I'd probably consider disconnecting the other strut. If the hinges on your RX330 are similar to the ones on my RX300, I just don't see how they could cause the problem you are seeing. It's either the hinges or the other strut. I don't see where else to look.

One thing for sure, at 105K miles it's well past time for an ATF change. The good news is it's not too late. I would consider 50K to be a reasonable interval given the relatively low cost of an ATF change - especially if it's a DIY. This is also something that could/should be performed by a good independent shop - either Toyota or Lexus. Your Lexus service department will make you pay dearly for this relatively simple procedure.

Sounds like a failed strut on one side or the other. There isn't much else to cause the symptoms you describe. If you determine that's what it is and you have to get ugly with it and cut it out, remember: those are gas-filled struts and there is both oil and nitrogen under pressure inside. If they are the original struts, much of the pressure has probably leaked down but there is still a mechanical spring which will release all it's energy at the first opportunity. If it is a strut, I'd suggest you look here for a replacement: Mr. Lou's Lift Support Depot These will cost a LOT less than those from your friendly Lexus parts department and they'll also last a LOT longer based on my experience with 3 sets of OEM struts and one set from Mr. Lou. Let us know what you find out.

This is most likely the Air Mix Servo Motor failing. The good news is that is can annoy you a long time before it fails completely. I had and have the same problem but the first time it was "fixed" simply by cleaning the contacts where the control cable connects to the servo board. If you have to replace the air mix servo board, it isn't cheap but I think it's something under $200 but don't quote me on that. Here is a link to one discussion on the problem. Maybe it'll provide you some insight to the nature of the problem and the fix. Air Mix Servo Problem