Strange hum in the back
Thread Starter
Lead Lap
Joined: Aug 2004
Posts: 542
Likes: 3
From: New Jersey
Strange hum in the back
A couple of months ago I noticed a strange hum at 45 mph when the car was coasting--not at braking or acceleraating. First they said it was the brakes. At 67,000 miles I didn't really know. They were changed. It wasn't the brakes. The noise was still there. The mechanic rode in the car, climbed in the back of the RX and listened more. He determined it was the Differential. They ordered and changed the differential. The noise was still there only now it was at 30 mph only. Then they said it was the bearings. They changed one side. You guessed it, the noise was still there. They didn't even bother to return the car they ordered the other side. Now the car has been returned and it seems ok. I'm almost afraid to hear the noise. Anyone else experience this on a 1999 RX 300?
Ive heard of this issue before.. its actually usually not the bearing itself, its the dust shield behind it. But its common practice to replace the bearing at the same time. Usually a simple squirt of bearing grease in there will stop the noise.. but whenever i come across the problem, replacement of the part is the first thing we do. I hope all those parts were replaced under warranty and you didnt have to pay for it all... good luck with the car, hope its trouble free from now on 
Originally posted by LexRexBlue
After 2 weeks of driving I've concluded that the hum is still there, but at 25 mph coasting--not accelerating or braking. They have no clue as to what it is. Any other suggestions?
After 2 weeks of driving I've concluded that the hum is still there, but at 25 mph coasting--not accelerating or braking. They have no clue as to what it is. Any other suggestions?
Originally posted by LexRexBlue
They are Michelin Cross Terrain. They have been on the car almost a year now. What are cupped tires?
They are Michelin Cross Terrain. They have been on the car almost a year now. What are cupped tires?
Thread Starter
Lead Lap
Joined: Aug 2004
Posts: 542
Likes: 3
From: New Jersey
Thanks. I'll make sure they check when I bring the car in on Thursday. They are supposed to have a diagnostic mechanic drive with me to hear the noise. Would the sound from the cupping occur every time I'm at a specific speed, or just some times? It only occurs at odd times including every morning.
Trending Topics
Lexus Champion
Joined: May 2002
Posts: 2,781
Likes: 6
From: Georgia
You may need to ask them to check the exhaust hanger or exhaust pipe. You may backed into something and slightly bend the exhaust pipe a little bit, enough for the exhaust pipe to tough the body or some part of the car and make this humming noise.
I don't know what else can make this humming noise beside Differential, wheel bearing and cupped tire. They did everything they could, except checking on the exhaust hanger or the tow hook on the right rear by the muffler.
You can ask them to rotate the tires from back to front, test drive the car and see if the noise goes from back to front. If the noise still in the back , then it's not the tires,not the rear diff, not the rear wheel bearings, because they already replaced them. Ask them to look at something obvious under the car. For example, bend exhaust pipe, bend heat shield, or any under body covers that not in place and touching the body of the car.
I don't know what else can make this humming noise beside Differential, wheel bearing and cupped tire. They did everything they could, except checking on the exhaust hanger or the tow hook on the right rear by the muffler.
You can ask them to rotate the tires from back to front, test drive the car and see if the noise goes from back to front. If the noise still in the back , then it's not the tires,not the rear diff, not the rear wheel bearings, because they already replaced them. Ask them to look at something obvious under the car. For example, bend exhaust pipe, bend heat shield, or any under body covers that not in place and touching the body of the car.
Last edited by VVT-i; Oct 8, 2004 at 07:51 PM.
ClubLexus Stories
Celebrating Lexus & Toyota from Around the Globe
Lexus NX 350h: A Fuel-Sipping Secret Hot Hatch???
Michael S. Palmer
5 Best & 5 Worst Lexus Daily Drivers
Joe Kucinski
Top 5 Hottest Lexus & Toyotas in 2026 (Hardest To Buy)
Brett Foote
2026 Lexus IS 350 F Sport Review: The Last of Its Kind Still Rocks
Michael S. Palmer
Top 10 Most Confusing Things Lexus Has Ever Done!
Joe Kucinski
2026 Lexus ES Review: Lexus Re-Embraces Founding Principles
Michael S. Palmer
10 Lexus Bargains That are Cheaper Than a New Toyota RAV4
Joe Kucinski
8 Weirdest Things Lexus Has Ever Built
Verdad Gallardo
10 Lexus Designs That Have Aged Like Fine Wine
Verdad Gallardo
Thread Starter
Lead Lap
Joined: Aug 2004
Posts: 542
Likes: 3
From: New Jersey
Thanks. I'll print this up and run it by them. Fortunately, they are very nice at the Lexus service. If I wasn't planning on giving this car to my son to drive I'd probably just let it go since I have ordered a new one--even if it doesn't come until April!
. So, your new one is the Hybrid RX400??.
Thread Starter
Lead Lap
Joined: Aug 2004
Posts: 542
Likes: 3
From: New Jersey
Ah Yes. The new car is supposed to be the hybrid. I'm hoping it'll arrive in Feb. instead of March because my son will be pressuring me for my car. I saw it at the Lexus Taste of Luxury, but I wonder how it will drive. I'm not so confident that this whole process will work out smoothly.
Thread
Thread Starter
Forum
Replies
Last Post
