# Singing Bearings



## Mixtronic (May 8, 2010)

Either I drive like a beast, or the roads where I live are worse than I thought...

Before the humming started, I was having issues with my ABS in my MKV, e.g., if I panic stopped, the ABS, ESP, and BRAKE lights came on until I turned the car off and then on again, and poof, they were gone. 

Then one day, the humming started, which at first I thought was a flat spot in my tires from a panic stop, but being that loud a very seasoned mechanic told me tires won't make that loud of a noise, it was a bad bearing. Then it snowed (Snowtober) and the ABS for the front wheels activated and there were no warnings...the ABS module seems fine. Then it hit me...

Because the ABS sensor reads the wheel speed from the bearing (I would imagine/I have heard) and I hear the humming, my powers of deduction clue me to think that they are somehow connected.

Now it's just down to checking to see if the bearing is, in fact, f'ed up, and if it is, gaining the courage to take it apart and fix that SOB and get my car rolling smoothing again.


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## BsickPassat (May 10, 2010)

it's easier to buy a new hub/bearing for the front... the assembly is bolted onto the spindle.

The best price I can find:
http://metalmanparts.com/product.sc?productId=532&categoryId=79

...and ultimately purchased & used. The guy is a vendor at TDIclub


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## Mixtronic (May 8, 2010)

BsickPassat said:


> it's easier to buy a new hub/bearing for the front... the assembly is bolted onto the spindle.
> 
> The best price I can find:
> http://metalmanparts.com/product.sc?productId=532&categoryId=79
> ...


I can use this to replace a rear assembly? Not sure how that would work...


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## BsickPassat (May 10, 2010)

Mixtronic said:


> I can use this to replace a rear assembly? Not sure how that would work...


that's for the front only

rear uses a different hub/bearing kit 1k0 598 611


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## Mixtronic (May 8, 2010)

BsickPassat said:


> that's for the front only
> 
> rear uses a different hub/bearing kit 1k0 598 611


figured as much...but my question is, would a bad wheel bearing cause my ABS issues?


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## BsickPassat (May 10, 2010)

no


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## cuppie (May 4, 2005)

Bull.
Yes, a failed wheel bearing can (and will) cause brake control (ABS, etc) problems.

What's the wheel speed sensor read? A ring that's either in the wheel bearing, or attached to the CV joint or wheel hub (which itself is quite firmly bolted to the bearing.)
Failed bearing = play, and/or funly harmonics, both of which will affect the sensor's readings (play = varying air gap= erratic readings; funky harmonics = erratic readings.


In your case, are the two related? Maybe, maybe not. Only determination of which wheel bearing is failed, plus the fault(s) stored in the brake computer (all lights coming on does mean that fault(s) were set) will say with any degree of certainty. 
You (or a friend) have VCDS to read faults?

That said... you know that you have a fried wheel bearing. That needs fixed, regardless of brake control problems. (and, see above, too.)


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## BsickPassat (May 10, 2010)

Ive had failed wheel bearings on my old mk4 and my passat (similar to the op's car)... never had abs issues. there was a small touch of play but nothing to which caused issues with the abs system

in order for the wheel bearings to cause issues with the abs system is if it catastrophically fail where the seals blow out and the ball bearings are no longer properly supporting the races. then it will interfere with the wheel speed sensor readings. if this happens, the bearings aren't "singing"--- the car won't be that drivable

driving in the snow, then the abs system kicking in? since people in the area are reluctant to use snow tires...you can also chalk that up to the EDL or ESP system kicking in to maintain traction/control--- further enhanced that very few had snow tires on in October (even the snow tire faithful)


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## Mixtronic (May 8, 2010)

BsickPassat said:


> Ive had failed wheel bearings on my old mk4 and my passat (similar to the op's car)... never had abs issues. there was a small touch of play but nothing to which caused issues with the abs system
> 
> in order for the wheel bearings to cause issues with the abs system is if it catastrophically fail where the seals blow out and the ball bearings are no longer properly supporting the races. then it will interfere with the wheel speed sensor readings. if this happens, the bearings aren't "singing"--- the car won't be that drivable
> 
> driving in the snow, then the abs system kicking in? since people in the area are reluctant to use snow tires...you can also chalk that up to the EDL or ESP system kicking in to maintain traction/control--- further enhanced that very few had snow tires on in October (even the snow tire faithful)


Here's an example; driving at highway speed, I hit the brakes hard coming to a light that changed to red, ABS/TCS/Brake lights came on, audible alert came from the dash and the wheels locked up. 

Later on, after the snowfall, I was driving down my block and got on the brakes. The brake pedal pulsated, ABS came on, but there were no warnings, etc. 10 minutes later, I whipped a quick turn to see if my TCS worked, and then I had the same warning as the panic stop.

01130 - ABS Operation 
008 - Implausible Signal - Intermittent
Freeze Frame 
Fault Status: 00101000
Fault Priority: 1
Fault Frequency: 7
Reset counter: 75
Mileage: 95552 km
Time Indication: 0

Freeze Frame 
Count: 17472
Count: 57344
Count: 12800
Count: 125
Count: 45626
Count: 65534
Count: 253
Count: 5120 

There's the code, I was told it could be the ABS module, but I really doubt that since I have had ABS properly work at times.


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## BsickPassat (May 10, 2010)

the scan does say "intermittent". so it happens here and there

take it to a shop to get it fully evaluated


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