Wierd noise / light shake around 1400-1600 RPM

[sonnyshah]

So they day after I purchased my RX350, I noticed a weird shaking and noise when accelerating / driving in the 1400-1600 rpm range. At first I thought it was the road but it happened consistently. Anyone else going through this problem?

I brought it back to my lexus dealer and all the mechanic said that it was a known problem and that lexus has not released a fix yet.

Any thoughts?

[TrevC]

Sounds engine related if its only between a certain rev range and not road speed.

My thoughts would be a static imbalance on the crankshaft area...crank pulley, flywheel?

[Lexus_DK]

It can be anything. But try checking if it's more related to the exhaust. I know the newer RX (or maybe the NX) has a exhaust sound issue. Even with the exhaust dampers, it doesn't fix the rumble sound.

[Lexus_DK]

Does it occur if you leave it in park and rev up to 1000-2000 rpm?

[old1goatroper@yahoo.com]

the service guy at the dealership says a few people are complaining, yes you are right, its exhaust resonance issue at 1100 to about 1900 rpm. I have even cut pipes 4 in from muffler and swiveled them down at a 45 deg., helps a little bit, but its definetly exhaust..

[old1goatroper@yahoo.com]

Went to lexus dealer today. They ordered me a supposed fix for the resonance problem. Its is a pipe that comes that comes off the exhaust manifold. The Tech Service Bulletin says its the fix. It doesn"'t fix it. They have added a weight on a 3" bracket welded to the old first pipe off manifold. Waste of gas, 250 mile round trip. Seems like they have engineers that could work on this problem.🤔