2013 RX 450h with 170k miles. Recent plugs and coil; new brakes this weekend, and new EGR due to a code.

My wife complained about some loud noises so I took the car for a test drive and I'm worried. There's a loud droning sound which clocked in at 80dB around 65mph. It seems to be rotational and related to vehicle speed, not from the engine.

I can't find anything obviously wrong. From the noise, I'd expect a wheel bearing or CV joint issue. I don't see any fluid or leaks. I've heard about transmission issues and the "lifetime" fluid that needs to be replaced. Can you give me some advice for troubleshooting?

I did see a small plume of blue smoke on cold start one time, but I don't see any other evidence of oil consumption. I might have put the EGR gaskets on the wrong way around. But, again, this doesn't sound like an engine issue. I've worked on some old cars in my day; is there such a thing as repacking wheel bearings? How would you track down the source?

 

Look at this thread regarding that droning noise, then skip to around post 78 for the solution someone developed. I did this on my RX and it did help. Unless you do have a bad wheel bearing...if that is the case the front hub is replaced.
https://www.clublexus.com/forums/rx-...e-sound-6.html

 

The bearing usually hums at lower speeds. Try 20.40 mph and turn slightly left and right. the load on the front bearings will change and the noise will change. Kind of slalom the car. If noise not change looks like not front.

 

I once noticed some strange droaning sounds that varied with speed on a road trip through the desert (lots of tumbleweeds) I pulled over and looked under the car and notice that a small stick had wedged between one of the leading edges of one of the many plastic panels under the car. I removed it and the noise was gone.

 

Closing the loop here:

Based on advice here, I drove the car and paid attention to the noise when turning and found the problem to be the passenger side wheel bearing.

Because I’m simulating cheap and thorough, I replaced the entire front knuckle assemblies on both sides. This included the bearing and hub and avoided the need for special tools like a machine press. This is something I can replace in my driveway and save the labor costs.

Of course, things didn’t go as planned. The brake rotors were seized once hubs, so I had to replace those, too. Whole reassembling the passenger side, I pulled the CV axle apart. The passenger CV axle also has a bearing halfway between the transmission and the wheel, so I replaced it, too. Removal took me about 10 days; that bearing was also seized. I ended up removing and replacing the CV/engine mount where the bearing sits. Even after I got it out, I couldn’t break it loose with PB Blaster and 4# sledge. That’s the one part I actually had to buy from the dealer - yes, it was the most expensive.

After getting it all back together, it seems I didn’t get the axle bearing retainer clip seated correctly; the axle slipped out of the transmission (after about 40 miles of in-town driving) and had to be towed to the dealer. I honestly thought I had broken the transmission; this diagnosis was a bit of a relief.

Now, she’s got a whole new front running setup and rolls smooth as silk. Ended up setting me back about $1,400, which is more than I had hoped, but less than the dealer wanted for the single bearing replacement.

 

Wow! What an adventure!

I gotta ask…. Did all that work eliminate the noise?