11 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHHumming noise from front of 2000 C4 Cab?
Leading reported evidence
Replace left front diff bearing seal
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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Discussions that performed work without a confirmed outcome
1
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Performed · outcome unconfirmed
The left front diff bearing seal has been changed twice now.
Leading evidence: 'Replace left front diff bearing seal' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check fluid levels and/or' (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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Suggestion
check fluid levels and/or change fluids....(how many miles on the car?) I changed tranny fluid and was shocked how quiet the car became...
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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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1
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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
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Suggestion · Original poster
I will check the trans fluid just to be doubly sure.
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.
11 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
2 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
Got it fixed (along with new brakes while hub assembly was apart) and all is good.
I recently bought a 2000 C4 cab with 54,000 miles on it. Everything is solid on the car except for a noticeable hum from the front end at around 70 MPH and above. It increasing in pace with the speed of the wheels and is not tied to engine speed. I'm thinking it's front bearings that need replacing. Or perhaps this is a common sound due to the all wheel drive. Didn't notice the hum when I test drove it and the Porsche dealer gave it a good going over. Any thoughts or tips? Oh and if it's a bearing job, what are your experiences with cost or DIY ability of that job on a 996 C4?
Glen
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'00 996 C4 Cabriolet
Welcome to RL, please take a moment when you get time and introduce yourself wil a couple pics of the car as well. This is a great place to come and share, gain knowledge and have a spot of fun. Please also report back on your findings so people can benefit from your experiences too...
humming -
check the obvious... many tires make humming sounds, if you have access to another set, swap them and see if the sound changes.
check fluid levels and/or change fluids....(how many miles on the car?) I changed tranny fluid and was shocked how quiet the car became... didnt even think I had a noise
wheel bearing is a PITA to replace - AND expensive... not a DIY job unless you have a good hydrolic press and the availability of materials and machines to make some tooling for the job (IMO - its a "shop job" for most people)
I dont have a C4 so others will have better data on what other noises you might be hearing up there...
GL and again - Welcome
Thanks. The car was recently aligned but the tires were not swapped. It was pretty out of whack so there may be uneven wear. I will check the trans fluid just to be doubly sure. And thanks for the welcome. Photos to come.
Cheers.
where are you located? (state-city)
Also check the fluids up front - there is a ? differential ? up there
what tires are on the car? (make/model) - some people might be able to offer opinion on tire noise better
Wheel bearings on these are not like the old Chevy (dammit anyhow)
Your car should not make that noise. It could be a bearing, front diff, or tires. Pirellis are known for being noisy. Normally a wheel bearing is very loud around 45mph. The best thing to do would be take it to a shop and have them diagnose the problem.
I had the same issue a couple of months ago, Had the wheels trued up, alignment checked and tires balanced before determining it was a wheel bearing. Got it fixed (along with new brakes while hub assembly was apart) and all is good. Not cheap, but what is at the shop...?
Had my '03 C4S in the shop this past week - some whining during lower speed driving. Mechanic put it on air lift and went through all gears, saw a couple millimeters of lateral play on the drivers side axel. He also said diff was low on oil with some in the pan. However I never had any oil on garage floor. He put a new seal in, but he said it is still leaking, and this is the 2nd seal (he's right, I have paperwork describing previous owner's repairs). Also told me it will leak when driven, but NOT when parked. So now faced with rebuilding the diff, or getting a salvage diff, or *heaven forbid* a new diff from Porsche.
Any thoughts out there?
DC4
Welcome!
I would suspect that it is a tire issue, but it could be bearings. On the other hand, I have a 2000 C4 Cab as well and there is no question that it is a bit noisier at speed than a c2. It would make sense- more parts are moving.
I would add +1 to everything that Ed (Ivangene) said....
It is indeed the front. The left front diff bearing seal has been changed twice now.
QUESTION: what would you do? New front diff, used front diff or replace bearings and seals?
DC4
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