gadgetman1

Johnkey

Having trouble with my new car. I get a vibration when rpm is at 1500. Lexus service not able to solve. Any one have any ideas

dwayneir

Check out this thread ....

https://www.clublexus.com/forums/rx-...vibration.html

It will tell you more than you wanted to know about this issue

Incidentally... there's a TSB that I just had applied to my 2017 which improved the issue quite a bit. I don't know if it applies to 2018 though.

Good luck,
Dwayne

computerwi

Sorry, have been extremely busy this past few months. Dealer opened a TAS case for my vibration and noted that at least 2 other clients have similar complaints of vibration/droning. After the rear exhaust assembly was replaced, it helped a but did not go away completely. In particular, the vibration is 99% gone but the droning was reduced by about half. Dealer mentioned they had some success with some clients by installing an "insulator" piece, which is really just the lower rear engine mount. Part # 12371-0P350. This has definitely reduced the vibration and the perception of transmission hesitation. I'd say it's an 80% improvement. So, 80% with the exhaust replacement and 80% with this is about 95% better than without any fix. Note, this fix was not explicitly authorized by the headquarters. The manager showed me the TAS case history and headquarters actually said to leave it alone after the rear assembly exhaust replacement as there was no "official fix" approved yet.

I should note that after the mount was replaced, my steering alignment was way out and I had to return for an alignment (luckily dealer agreed to cover this). I was told it may been caused during the lowering of the subframe, which was required to access the mount.

NS68

The dealer doesn't believe it but mine too has "vibes" between 1500 and 2000 RPM... I have tried different gas stations just in case, but no change...

allwheels

There is no bulletin for the engine mount.

rxtimes2

I had the "Exhaust Drone at Takeoff Under Light Acceleration" TSB (L-SB-0003-18) done a few days ago on my 2016. Like others have reported the rumble seems to be even worse now. The vibration is most noticeable around 1500 RPM. Now, when accelerating, I try to keep the RPMs above that range. Bummer. I wish l could remove the harmonic dampener on the side of the unit, and change its weight until the drone was negated. If I had access to a lift, I might try to tune the system.

rxtimes2

Yesterday I reported that the droning noise was worse after completing the exhaust pipe TSB. Today I removed the weight attached to the center exhaust pipe assembly. Two bolts -- easy to do. I need to drive it for awhile to see if the droning has at least returned to the pre TSB level. I will keep you posted.

guxu

So the TSB is just a weight? I thought my dealer replaced a pipe or something and charged Lexus more than $1k. Does that weight cost $1k+?

rxtimes2

The TSB includes a new center exhaust pipe section which does indeed cost over $1K. Welded to the new center section is a bracket that holds the round weight (seems to be about 3 LBS or so). I am pretty sure that this section of the exhaust also contains the catalytic converter, hence the big dollars.

So far, the exhaust drone seems to be better without the weight. If I get the time, I might try and tune the system by adding different amounts of weight in the form of washers.

pqn628

A couple weeks after completing the TSB, the drone came back but at highway speeds. I added another damper to the front of the resonator and there is no more drone.

rxtimes2

rxtimes2

This morning I put a bolt with 10 large fender washers on it into one of the empty TSB exhaust pipe damper holes. I previously removed the damper when the drone got worse after the TSB installation. The weight of this test bolt and washers was about 1/3 of the the TSB damper weight. The drone got significantly worse. My test is 60 mph in normal mode. RPM at this setting is about 1500.

RealWing

The damper weight is rubber mounted to the bracket which is the best design to reduce the vibrations. You test definitely shows that the damper is reducing (ie not eliminating) the vibes. pqn628 maybe has the best fix to add a second damper. That is what I did on my 2015 RX to fix my vibration/drone- even though the exhaust pipe design is different.
Jim

rxtimes2

Thanks RealWing, and absolutely right. The damper has real hard rubber bushings that isolate it a bit. I do know the mine was much worse with that damper in place. If a second damper up front works, I am all for it. I believe pgn628 also fitted the second damper to a 2015. I hope that someone with a 4th gen 350 has fitted a second damper to the TSB pipe. I see pictures in this thread of a second damper fitted to a stock center section but not one that has the TSB pipe installed. Might have to give it a try. Wish I had a lift.