currancchs

Vehicle is making a loud, metallic rattle a few seconds AFTER being started when it has not been started in at least a few hours (i.e. cold soak). You can actually see the driver's side tire move a bit to the tempo of the rattle, like something is hitting it periodically. The fact that the noise occurs a few seconds after the vehicle is started, in my opinion, tends to point away from any oil pressure/delayed pressure issues (i.e. VVT actuators dry until repressurized). It really sounds to me like a gear clatter, but is quite loud and, I feel, really shouldn't be considered normal on a car like this. Additional information is provided below:

Vehicle information:

1. Vehicle is a 2012 RX450H (the hybrid w/CVT)
2. Vehicle has ~103k miles
3. Vehicle was bought recently, problem was noticed a few weeks after purchase (intermittent/hard to hear from inside cabin with windows up)
4. Weather has been between low 50's to high 70's on morning starts.

Here is a video of the issue:
Already tried the following (mostly done as preventative maintenance/we're already there sort of stuff):

1. Replaced all spark plugs and rear 3 ignition coils (only the three rear coils were done because the fronts are easy to access)
2. Replaced all EGR/EGR cooler, throttle body, and intake manifold gaskets (these parts needed to come off to get to the plugs and a previous test had shown that the lower EGR gasket was leaking slightly)
3. Changed transmission (CVT) fluid and rear differential (power supply unit?) fluid (used factory Toyota WS fluid)
4. Cleaned throttle body, EGR valve, and MAF with appropriate aerosol cleaners
5. Sent factory fuel injectors out for testing and cleaning (one injector was down ~35% on static flow, all improved by at least 8% after cleaning and are within ~2% of each other)
6. Checked fuel trims before and after (before LTFT was ~+10% on the rear bank, ~+4% on front bank, now hovers around 0% on both banks

The hybrid and auxiliary batteries were disconnected for the duration of the repair (~1 week - waiting for fuel injectors to come back from cleaning).

Noise seems to have diminished a bit after these repairs, but is still there. Goes away completely as soon as the vehicle is put into gear. As stated previously, I suspect CVT gear clatter and that the engine running slightly smoother now makes the noise less noticeable, but it idles pretty smoothly now and still makes the noise, which I feel is not right on a luxury car like this.

Lastly, I know that the earlier RX400h's had an ISC or idle relearn procedure that could be done without the factory scan tool that allegedly could reduce gear clatter noise, but have found no indication that this applies to my 2012 (the TSB was for the '06 and '08 models and is attached here). If anyone knows if the ISC procedure is still applicable, please do let me know (I have an Autel Maxisys scan tool, but no factory tool or tech stream, although I may buy one eventually)!

Any insights from those who may have been there/done that would be greatly appreciated. Thanks!

-Matt

Droid13

After over 10 yrs and 200,000km I'm starting to get a little more gear noise from my CVT, but I typically only hear it just as I come to a stop in my garage under electric power only when its quiet and the walls echo the sound, a momentary little rattle I guess just as the drive pressure releases. I've noticed a similar noise from the CVT when I had the front wheels in the air and slightly rotating the wheels and drive shafts against the park lock. I recently had the CVT fluid changed cuz it was due, but it had no effect on this particular noise. When you talk about the driver's tire moving, are you referring to when the tire is lifted off the ground?

Don't notice anything with the engine running mainly due to engine noise, especially when cold as the idle is high and I'm usually half way down the driveway when it starts.

currancchs

Hi Droid13, thanks for taking a stab at this one! The only time the car makes this sound is between about 5-20 seconds after the first start of the day, which tends to be in the relatively early morning (e.g. 7-8am). When I refer to the driver's side tire moving, I mean that when the car is on the ground normally, the tire seems to almost want to rotate, like something is causing the axle to momentarily want to spin, despite the vehicle being in park.

My father has a video of the vehicle having the issue, which will likely be more helpful than my description. I've asked him to send it to me and will post it on YouTube and post a link here (or embed, if possible) to give everyone a better idea of the nature of the issue (this has been added now!). Sorry about not posting that in the first place!

alisher

I have absolutely same issue on my CPO RX450h.

Showed to few dealers and looks like they hiring deaf persons because every time I had to leave car to stay overnight and mechanic coldn't hear anything, then I have to come next morning and sound appears mystically ("It wasn't like this yesterday, man").

But worst thing dealerships blaming on bad fuel, bad oil and last one said "This is normal tear and wear, your car is just getting old".

Had to escalate to Lexus general and made an appointment for next Tuesday with service manager.

If they will be able to fix it, I'll let you know.


P.S. What's in attachment in your post? Couldn't open it.

currancchs

Hi alisher, thanks for sharing a video of your vehicle. Sounds like the same exact issue to my ears! Would be very interested to hear what the service manager has to say, please do share after your visit.

My own experience visiting with a dealer (albeit only one) was similar. They kept the car for a week and claimed it was an engine mount one day, then ruled that out the next and said it was the "intake manifold" (not a vacuum leak, mind you, but the manifold itself). I have no idea how they came to this conclusion, as the vehicle actually belongs to my dad, I just wrench on it sometimes for him, and he is the one that brought it to the dealer and picked it up. I did notice a few vacuum leaks in this area during my own inspection and subsequent teardown and was also able to confirm that they were resolved by my repairs, but, as mentioned in my first post, the rattle issue remains.

Regarding the attachment, the attachment was Lexus's ISC (Idle Speed Control) relearn instructions (for the '06 RX400h). Apparently that procedure was required after disconnecting the auxiliary battery (i.e. the 12v battery in the trunk). If it was not performed, one of the "common customer complaints" was more audible "gear clatter", which the CVT on our vehicles is apparently prone to producing. I did not do the ISC relearn procedure, either before or after my repairs, but may this weekend. Am a bit hesitant to hold the brake and throttle together though (a part of the process) without any clear documentation that this procedure is applicable to our generation RX hybrid (latest confirmation I could find applied to the '08 RX400h). Also, not sure why it didn't attach correctly the first time. I've just re-uploaded it and it appears to be downloadable now.

Thanks again and keep us posted!

currancchs

So, had another chance to look at the vehicle this weekend and have some interesting notes to share. First, it does appear that the ISC relearn procedure is available on the 2012 RX450h. I say this because my Autel Maxisys scan tool ( ) showed ISC learn status as "incomplete" when checked and there was also an ISC learn parameter available, which read ~2.5 l/s (not sure of units, Liters per second of air maybe?).

I can also confirm that the procedure described in the PDF attached to my first post works on the '12 RX450h, with one significant caveat. While the attached PDF states that you must monitor calculated load and keep it above 45% for 30 seconds, with the car in gear and brake on, to initiate the process, this does not appear to be correct for the '12 model. More specifically, the calculated load would jump quickly to ~30% (as viewed on scan tool) when the accelerator was depressed, with the vehicle in gear and brake on, but was then fairly unresponsive until near 3/4 throttle was applied, at which time load jumped to ~80%. As I did not feel comfortable applying so much throttle while also on the brakes for 30 seconds, I ceased the test and started again, keeping calculated load above 30% for ~30 seconds before shutting off the car, waiting 5 seconds, and putting it in the "ready on" position. The engine started and ran for ~45 seconds, during which time the ISC learn parameter adjusted from ~2.5 l/s to just over 3 l/s. Immediately after engine shutdown, which was automatic, the ISC learn status parameter changed to "complete".

After performing this procedure, the car seemed to idle very nicely (it idled pretty well before though too), maybe slightly higher than normal. There were no rattles or other noises associated with a semi-cold startup a few hours later. I will update if the problem returns, but am still interested in other's experiences with this issue in the meantime.

p.s. alisher - you may wish to share this information with the dealer on your visit, as many are apparently not aware of this procedure, especially on the later model hybrids.

currancchs

Just another quick update, checked on the car yesterday morning and this morning. Yesterday the rattle was faint, couldn't hear anything this morning. Temps have been in the 60's or so around here. I'll update again if the noise comes back in force or stays gone for at least a few weeks.

P.s. alisher - How did your trip to the dealer go? Hope that you were able to resolve you issue!

alisher

Hi. I dropped my car at the dealership yesterday. Before leaving the dealership have talked with Service Foreman (?) Gary and showed him video. He promised to connect diagnostic tools after overnight stay and if computer will show any errors consult with Lexus. No response from them today.
BTW I told him about re-learning procedure for gearbox and he stated this procedure is only for 2nd gen RX.

currancchs

Hi Alisher, thanks for the update! Interesting that my scan tool shows ISC learn value/status and shows a change, in both value (~20% change - ~2.5 to ~3.0) and status (incomplete to complete), after following the ISC learn instructions from the PDF associated with the 2nd gen that is attached to my first post, but the dealer claims this procedure is not applicable. Certainly seems to be on my '12 RX450h... Also, I do not think that the relearn procedure does anything to the gearbox, I believe it calibrates the throttle body and/or idle speed control valve, with the side effect of a smoother, perhaps slightly higher idle being that the inherent slight rattle in our CVTs is less noticeable; at least that is my understanding.

alisher

I've got call from dealership - they are going to change injectors. Car should be ready on Monday.
About re-learning - when I was talking with foreman he said front wheels shaking is related with engine, it happens due to different organization of gearbox.
If car keep rattling, I'll tell them.

currancchs

Very interesting information, thanks for sharing!

Not sure if you're paying out of pocket or its under warranty, but, if paying out of pocket, you may want to consider an injector cleaning service rather than replacement. I had all 6 injectors flow tested, disassembled, filters replaced, cleaned, and flow tested again for ~$100. Cleaning/testing took about 3-4 days. I used these guys: http://hurstinjectorservice.com/faqs.html (located in Fitchburg, MA). Compared to the $157 per injector I was able to find them for, I figured it was worth a shot and it worked out better than expected (flow testing showed 3/6 were quite restricted prior to cleaning, but all were within ~2% after cleaning).

P.s. I'm guessing the dealer went through the procedure in the attached TSB prior to deciding to replace injectors. TSB states that this can be the cause of rough running and I believe that the rough running causes the rattle, so that would make sense. It's also a major part of why I had my injectors serviced while addressing my other issues (see first post).

alisher

The first thing what I did at the first visit to current dealer - showed them the TSB. They refused to accept it due no error codes on my car. Had to write to service manager with explanation and videos. Only after that dealership agreed to take a look again and decided to change injectors. It's warranty work, otherwise I will do it somewhere else for much cheaper (based on prices from this thread).

alisher

I have got my car back 2 days ago. They replaced 6 injectors. I haven’t heard any click in those 2 days and car feels a little faster now. Also I had bad MPG - 21-22, will see how it will change.

currancchs

Glad your problem seems to be resolved, thank you for taking the time to update us!

BVD2012

This sounds like the sound a bad water pump bearing made on my 2008 RAV4 3.5L CVT AWD. The pump never leaked coolant, but after the belt was removed you could feel about 1 mm of play at the pulley. It had about 100K miles on it. After a new $150 pump was installed (with zero play at the pulley) the noise stopped. The transverse V6 required removal of the front mount and supporting of the engine on a jack to get the old pump out. The bearing noise was hard to pinpoint and was RPM sensitive - lots of resonant surfaces in the 3.5L. Maybe not it, but something to check. A water pump is a lot cheaper that a CVT rebuild...