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Discussion summary
YOUR RESEARCH996 problem, wheel bearing?
Leading reported evidence
Replace before it seizes up
Performed · outcome unconfirmed
No successful repair reported for this finding.
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1
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Read evidence and context
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Suggestion
It might be worth checking your cv boots on the driveshafts I know porsche cv failure is rare but if the rubber is split and you lost the grease and all sorts of muck got in there it will cause damage, a cv normally clunks when turning where a wheel bearing is more of a humming noise, hope this helps!
Leading evidence: 'Replace before it seizes up' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'bearing' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check cv boots' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed
I had a power steering pump replaced on my Mini Cooper S and had a strange vibration that was not easy to reproduce.
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Performed · outcome unconfirmed
Also changed two wheel bearings that failed the wobble test and had NO noise symptoms.
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Suspected cause
Because Gretch doesn't think it was the wheel bearing.
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Check cv boots
No successful repair reported for this finding.
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Suggestion
It might be worth checking your cv boots on the driveshafts I know porsche cv failure is rare but if the rubber is split and you lost the grease and all sorts of muck got in there it will cause damage, a cv normally clunks when turning where a wheel bearing is more of a humming noise, hope this helps!
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
30 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
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Hello chaps,
I wonder if you can help with a nasty problem that has just occurred on my 1999 C4 996.
Only gets driven once a week these days, brakes are a bit bindy for a while but other than that all goes well.
Had some new rear tyres last time I drove it.
Back from 2 week hol, take car to work, brakes a bit bindy...
I find that on a right hand bend, with moderare acceleration - terrible noise from the front, maybe left front wheel. Stops happening after a second or two and all perfectly fine when going straight or right turn with low acceleration. It is repeatable.
Could the psm be kicking in due to the tread depth delta of the tyres? Really bad noise though, difficult to describe. I noticed a red light flash on but not sure which one. Drive shaft?
Had it up on jacks, nothing unusual at full lock turning wheels by hand.
Any help appreciated please.
The noise sounds like a wheel bearing. Easy check. Jack up the left front. Grab the top and bottom of the tire and try to rock it. Shouldn't be any play. If there is, probably the bearing. That's the most likely based on the noise.
Thanks for the replies chaps.
The car has around 80,000 miles.
Will give the wheel a wobble and let you know.
Why is it just on right hand turns? It goes as well as it ever did in a straight line?
By the way, this isn't just a little rumbling noise or whining, it's a very nasty grinding/interference type noise.
Why would a light come on - red I think - unless it was me stalling the thing with shock....
With the wheel off the ground, it rotates smooth enough. It's a C4 so it doesn't just spin.
I don't know the precise functionality but the tell tale symptom of a bad bearing is a loud grinding/groaning noise in turns. Bad left bearing makes noise in right hand turns and vice versa.
If it's really bad the wheel will be wobbling on the axle which could cause the traction control systems to think something is amiss. It's not a guarantee that's your issue but definitely start there.
Hello all,
Just jacked up each of the front wheels, I can detect no play at all when trying to wobble top and bottom of tyre as hard as I can.
What next?
Any ideas appreciated...
Not all "wheel wobble" tests will manifest as a bad wheel bearing. Symptoms suggest a bad wheel bearing. Think of the mass and g-forces exerted on the car when turning, and the forces on the wheel bearing. Grinding crunchy terrible noise may be a wheel bearing going bad, yet not bad enough to wobble. When making a right hand turn, the mass of the car is on the left side, placing a lot of load on the front left wheel bearing. Could be going bad, but not bad enough to wobble.
While others have offered wheel bearing and it is a good guess it reads more like a brake problem.
Reads like rotor and pad contact which results in the noise. I want to believe the light you saw was the brake wear warning light.
You need to carefully check the condition of the brakes, the pads, the rotors, all the hardware.
And "brakes a bit bindy" needs to be investigated too.The brakes should not be binding.
FYI - spoke to my local Porsche dealer.
He suggests checking for a spring failure.
He also says he has never seen a drive shaft failure and that it's difficult to determine a wheel bearing fault by wobbling the wheel.
I'll check the sprint and if that doesn't show anything I'll take it in and let him have a look.
Thanks for all the comments.
I'm just doing the wheel bearing on mine, well I'm actually cheating and swapping the hub but I didn't have any play in the beating just the noise but luckily I can tell what a wheel bearing sounds like and I could make the noise happen by turning whilst driving. Only when I got the brake disk off and turned the hub by hand could I feel the notchy rough feeling as I turned the hub so could still be the bearing! It might be worth checking your cv boots on the driveshafts I know porsche cv failure is rare but if the rubber is split and you lost the grease and all sorts of muck got in there it will cause damage, a cv normally clunks when turning where a wheel bearing is more of a humming noise, hope this helps!
While the wheels are off for checking the springs, I will check the condition of the boot too - although I did have a quick look previously.
Can I reinforce the severity of the noise - it was not something that one would ever consider continuing to drive through.
I only did continue to drive the rest of my 30 miles to work because when I slowed down and straightened up it went away completely. Only 15 miles further on at the next roundabout (do you guys know what one of those is) did it reoccur, and again went away on the straight. After that I was very careful to drive very slowly around RH bends.
A sensible person, like I am not, would have stopped and got(ten) towed away.
So I don't know what your experience of wheel-bearing or brake noise is, but mine is nothing like this.
"Roundabout": British term for traffic circle. Yeah, we know what they are and even have some in some areas. I just wish American drivers knew how to make them work!!! Fun to drive through in a P-car though. Keep us updated.
Yeah I'm also from uk !!!
Sounds like cv joint to me, they sound really bad when they are going , you can also feel it through the steering usually, go on a car park and drive in a circle with full lock , it will clunck like mad!
Yep, C4, CV, been there, done that with those exact symptoms. Also changed two wheel bearings that failed the wobble test and had NO noise symptoms. Reach in and try and move axle up and down.
Update:
Well I visited my P dealer and we drove around burning fuel for quite some time but could not reproduce the issue. He put the car on the lift and checked a few things, but could not see anything wrong.
On the way home, I did reproduce the issue. It seems to be at a specific speed and curve that does it.
I'll try and record it and post it up for you guys to listen to...
Let us know. I had a power steering pump replaced on my Mini Cooper S and had a strange vibration that was not easy to reproduce. They ended up discovering a resonance by a flapping cooling fan, so sometimes the cause it pretty well hidden.
My car starting with an intermittent whinning noise above 65 mph that would stop below 50. A month and 1000 miles later, the whinning became systematic about 55 mph and stopping below 40. Whobble not as disturbing than the whine. The noise was coming from the right side. I just took my car for 10k service to my P dealer and verdict was a bad right front wheel bearing. They changed it and the noise is gonne! A pleasure to drive a quiet car on highway. My car has 78k miles. Bearing is pretty cheap at 89$, labor was not at 445$ plus 200$ for wheel alignment ... so 735$ total but luckily for me that was covered by my extended power train warranty: I just had to pay the 150$ deductible.
