22 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHDrone and vibration from 996 rear axle - help!
Reported or suspected cause
sway bar end links
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
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.
Discussions that report identifying a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Leading evidence: 'sway bar end links' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'sway bar end links' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check over and restored, and fresh tyres fitted' (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.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
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.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
* wheels checked over and restored, and fresh tyres fitted
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.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
I'd been putting off the alignment until I fitted the new suspension, but I fear it's looking as though it just needs to be all ripped off the car and started from scratch doing it properly...
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.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
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.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I replaced end links and bushings for about $110 for the front and same for the rear.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
I'd been putting off the alignment until I fitted the new suspension, but I fear it's looking as though it just needs to be all ripped off the car and started from scratch doing it properly...
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.
22 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.
3 acknowledgements have no verified action link; they do not establish a repair result.
Hello everybody,
I own a 2002 996 Carrera (3.6, C2, coupe, manual, etc).
I love the car, but I'm having an issue with it and just wondered if the symptoms rang any bells for any of you...
As the title to the post suggests, there's a droning noise and slight vibration that feels as though it's coming from the rear of the car.
When I bought the car it had some old, worn-out tyres on it, and so expert opinion was that these would be the culprit. There is also minor impact damage on the inside of one of the rear rims (apparently).
However, I've since had the wheels checked over and restored, and fresh tyres fitted, and it's no better. The damage is very slight to that wheel, according to various people, and nothing that shouldn't balance out.
The noise is very surface dependent: it can almost fade to nothing, but is at its worst at a constant higher speed - e.g. 50-70mph - and on coarse road surfaces. It can get so bad that you'd have to shout even to be heard. I've driven 996s before owning mine and know they don't do this (despite being susceptible to having some road noise on our poor roads). The vibration is always there - it's slight, but it just feels like the car is permanently struggling with something. All in, it just makes me not want to drive it, so I'm very keen to sort it out.
The car has done 80,000 miles and I know it could do with a full suspension re-fresh. Would just like to sort this out now though if possible before saving up and then spending the big money down the line...
Any ideas?
Thanks in advance.
When you got the tyres balanced do you get them Road Forced? This helped mine a little and is a cheap next step.
Its also feasible that the wheel bearing or CV joints could be the source.
http://www.pelicanparts.com/techarti..._CV_Joints.htm
For vibration I would suggest it needs to be a rotating part.
Does the noise change when accelerating vs constant speed vs decelerating?
Does the noise change when the clutch is pushed in vs out?
Does the noise change when going around a sweeping turn one way or the other?
You say the noise changes with the road surface... which leads me to think it's tires but let's rule out some other things while we're at it.
And yes, as said above... get an alignment.
Sounds like a bearing. If it goes away when the clutch is pushed it, could be in the gearbox. If not, a wheel. A bad wheel bearing will have some play when muscled around on jackstands.
Thanks for the replies everyone...
My next step is to get it looked at more closely by a specialist. It's already been to one place but they couldn't see anything wrong...
I'd been putting off the alignment until I fitted the new suspension, but I fear it's looking as though it just needs to be all ripped off the car and started from scratch doing it properly... For a start there's a creak from the front axle over large bumps. The tech that drove also commented it 'understeered a lot' so perhaps it's way out of alignment too...
There's no noise when the clutch is in - it's only with road speed. Gets worse the faster you go, but doesn't seem to vary with turning the 'wheel either way. The vibration seems to get worse sometimes when you do turn the 'wheel, having said that.
"There's no noise when the clutch is in"
This is the smoking gun. If all symptoms disappear when the clutch is depressed, the problem lives in the gearbox or engine.
Sorry, I think that's my mistake there and I replied too quickly. What I meant to say is that having the clutch in or out - when rolling - makes no difference to whether the noise is there or not. And there's no noise at all when at a standstill. Apologies again.
If the suspension kit is not stock parts that could be the root of the creak. I say this because a writer for EVO magazine mentioned that he had that same issue with an enhanced aftermarket suspension on his 996 and the suspension creaks were loud.
* droning noise and slight vibration...coming from the rear of the car
* wheels checked over and restored, and fresh tyres fitted
* its worst at a constant higher speed
* creak from the front axle over large bumps
* tech that drove also commented it 'understeered a lot'
* No change in noise with speed change
First, the clunking/creaking from the front suspension is probably unrelated.
With the car in the air, in neutral, have you spun both rear wheels by hand? If a bearing is shot, you will likely feel a bump or grinding from the affected ball(s). As Ditto suggested, grabbing each rear tire (wear gloves) and trying to wiggle it from side to side can reveal bearing play.
Worrying about why the front end sometimes clunks or creaks is fine, but not while you're trying to identify whatever is going on with the rear...
No, admit I haven't jacked it up and tried the wheels. I'm pretty sure that was done by a specialist not long after I got the car and noticed the problem. They also put a stethoscope to the 'box and other parts of the drivetrain back there and found no problems. Like others, they then blamed the old tyres! (the ones that have recently been replaced).
And it's speed related not RPM related?
I would get an alignment and another balance just to eliminate that from the equation.
With the windows down, the sound should get better or worse when turning if it's a wheel bearing.
Next up is the axle. You can get a salvage one for $100 and the swap out is a couple of hours DIY (so plan a day of you're not familiar with these). Read through the pelican how to prior to make sure you have the tools on hand.
It does get louder with speed, but it's not a rotational sound that gets faster as the speed rises.
I haven't noticed any change in the noise when turning right or left. I do think that the vibration might get slightly worse when the 'wheel is turned though.
I brought my car in to change the motor mounts, and they found a transmission mount that was shot and in need of replacement. My clunking and droning went away completely after a new mount. Maybe check this out as well?
For clarification: You will not be trying to troubleshoot this on your own?
Might as well quit soliciting suggestions, then - unless you really want to sour the relationship with whomever the car winds up with, in which case be sure to hand him a printout of this thread when you hand over the car.
For maximum impact, use the following wording:
"I know you're supposed to be pretty good, but I got some
expert
advice off the Internet."
You really need to emphasize "expert" - you can't hit that word too hard. It's key; do it wrong, and he's merely annoyed; do it just right, and he'll go berserk.
You have vibration and noise: I simply HATE taking my car into the shop for stuff like this...they always misdiagnose or write up 5 other things that might be wrong instead of the primary cause. My advice is to jack it up or put it on a rack and figure out what is worn out. There should be no play and usually your eyes can spot something that is loose/worn. I spent perhaps $500 on my front end and over 10 hours replacing parts. I still have to replace the struts and tires but it is 95% better than it was.
I'm thinking you should have those tires' balance re-checked and also a 4 wheel alignment is in order. If there is a slight jarring that is enough to cause some "curbage" or scarring of the inside of the rim, it could have knocked that wheel out pf alignment. The only way you can tell for sure if alignment is out, is uneven tire wear. Since you have new tires...the evidence was thrown away with the old tires.
I had a very similar set of problems on my 139,000 mile 2001 996: clunking and drone.
Tires make a HUGE difference. I replaced Pirellis with Michelin PS2s and it was a great improvement. I could barely stand to be in the car with the Pirellis.
Clunking proved to be sway bar end links. I replaced end links and bushings for about $110 for the front and same for the rear. Big improvement. Clunks are gone.
I still have some droning. Speed related, not RPM. Toeing the brake doesn't seem to change the drone. I don't think it can be the tranny mount as the drone is the same with clutch disengaged. I suspect wheel bearing and/or CV joint. Will work on that.
This is a source reference. Confirm exact model applicability in the original material.
