DMPesso

Whats up CL, I have an 01 GS430 with 150k and just recently my car started making this really loud noise. You can hear the noise while idling and when driving normal, sort of like a lawnmower or jet engine, just really loud and abnoxious compared to how it just sounded a week ago. When you are driving and are pressing the gas it isnt AS BAD as when you finally let go of the gas, that is when you hear it the most profound, after accellerating and letting go of the gas its like a deep whining jet engine sound as if you hear the backpressure of the exhaust flowing through. Also at the same time coinsidently I sometimes hear my exhaust make a slight rattling sound like a piece of metal stuck in a can that my mechanic said is coming from the middle rear cat. This doesnt seem to coinside with the super loud noise because the loud jet engine noise you can hear from the front of the car towards the manifold/engine area. If anyone knows what this can possibly be PLEASE let me know, because my mechanic seems to think its the front CATS but I cant imagine those causing this type of noise as they usually cause a rattling noise and I am usually really good with diagnosing stuff on this car but this one has me stumped!

Mr Jokster

iTrader: (8)

I was thinking cat too. Maybe even punctured. As always, noise sounds are best diagnosed with some type of audio video to be heard.

DMPesso

I will take one today. I just didn't think it was the cat because I'm used to cars making a rattling sound that you also hear while accelerating. This sounds like more of a deep bassy fan sound that happens even when the car is parked but more noticeable when driving and slowing down from speed.

DMPesso

So now a mechanic who took a quick ride and didnt have time to put it on a lift said its the hub or hub bearing. I believe him I don't know why I thought exhaust but now that I think about it the sound does have that deep whining sound. Can someone tell me what the part is called if I'm trying to find it. I want to replace the entire hub so I don't need to press the bearing. I am assuming I will just need the hub right ?

Mr Jokster

iTrader: (8)

Weird, usually you can just lift the car and spin the wheel to see if its the bub as well as see if it wobbles. Go to you tube and type in wheel bearing and watch all the symptoms of a bad bearing. Lets not mention... You said you hear it while at idle, never seen a wheel bearing spin while sitting in idle

DMPesso

What is considered a normal price for labor of replacing and pressing in just the wheel bearings? My mechanic was saying it's cheaper and better to buy the whole hub and spindle assembly because that comes with the bearing already pressed and attached and just replace that. What do you guys think? What should it cost to press and replace the bearings alone and what should I do?

DMPesso

Is the hub/spindle/bearing something that is wise to replace in pairs or is it one of those parts that randomly go bad and can I jus replace one side without making it drive better only on one side?

maxx430

I replaced my wife's rear wheel hub. Only did one side and it was making the same noise. The other side is perfectly fine and it been about 5k miles. No need to replace both side.

DMPesso

Thank you very much. I am going to pick a used one up today and get it swapped.

DMPesso

So I swapped it with a used one and I am still hearing the sound. Not sure if he's just saying that but he said it sounds a little better but the one I got is bad also but better then what I had. Not sure if it's coinsidence but the car seems to drive a little better but I still hear the noise a lot. A very deep hum. Now my question is are there any other parts that can cause this same noise/symptom because I don't want to change it for another one for nothing. The guy will give me a new one for free and the mechanic said he will do the labor for half price for me.

aliga

iTrader: (147)

Sounds like ur mechanic doesn't know what he is talking about. U wasted money on the part and labor.

DMPesso

Two different mechanics said thats the problem. My friend has a lot of these laying around so there is a chance I got a bad one. Now what I'm trying to figure out is if the same bearing noise can be attributed to anything else as well besides bearings. I changed the entire thing in one piece hub/bearing/spindle.

xHyaku

I don't get it. As Mr. Jokster stated, you were saying the noise also occurs during idle. How can that be a wheel bearing?

So does the noise still occur during idle or what?

If it is a bad wheel bearing, does the noise get louder if you load up the bearing from side to side?

Have you checked your idler pulley and drive belt tensioner? Tensioners usually rattle when they go bad.

Just a thought.

DMPesso

So sorry I should have fixed that. You do not hear it while idling. You only hear it when driving over 20 mostly 30-40 mph and up and it gets louder as you let go of the gas and are cruising. The idle noise was a different problem that I thought I had. What do you mean load up the bearing from side to side? How do I do that? Sounds like a good idea!

wbmx1981

The issue based on your description could be a "stuck" caliper slider pin, wheel bearing (but you swapped it out), or improper tire wear (lbjs, inner/outer tie rods). Noise at idle, would be a pulley bearing, bad pulley itself or a worn belt.