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911uk

Quiet knocking noise

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15 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHQuiet knocking noise

Reported or suspected cause

also a knocking noise

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.

Reported cause · Original poster

The second issue is also a knocking noise from the rear.

Quiet knocking noise
Frequently discussed work

Check over the bushings and they still look

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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've checked over the bushings and they still look clean and purple....

Quiet knocking noise
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Leading evidence: 'also a knocking noise' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'also a knocking noise' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check over the bushings and they still look' (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.

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1 matching discussions · 15 captured posts examined · 1 partial discussions

Compare 4 other evidence results

Check over the bushings and they still look

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
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 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've checked over the bushings and they still look clean and purple....

Quiet knocking noise

Check quite rusted and doesn't appear any movement

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
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 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

Thanks Alex - just checked - quite rusted and doesn't appear any movement....

Quiet knocking noise

Check sway bars and tried

Performed · outcome unconfirmed

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
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 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 checked the sway bars and tried to tighten with a wrench, but little to no movement.

Quiet knocking noise

Test drive

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
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 contain suggestions
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.

Suggestion

This will take any play up and you can take it for a test drive to see if its gone.

Quiet knocking noise
Frequently discussed actions (6)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Check over the bushings and they still look

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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've checked over the bushings and they still look clean and purple....

Quiet knocking noise

Check quite rusted and doesn't appear any movement

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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

Thanks Alex - just checked - quite rusted and doesn't appear any movement....

Quiet knocking noise

Check sway bars and tried

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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 checked the sway bars and tried to tighten with a wrench, but little to no movement.

Quiet knocking noise

Test drive

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
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.

Suggestion

This will take any play up and you can take it for a test drive to see if its gone.

Quiet knocking noise

Tighten were the sway arm bolts

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
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.

Suggestion · Original poster

Morning Alex - yes tried both - the only thing I could seem to tighten were the sway arm bolts.

Quiet knocking noise

Tighten with a wrench

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
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.

Suggestion · Original poster

I checked the sway bars and tried to tighten with a wrench, but little to no movement.

Quiet knocking noise
Reported and suspected causes (1)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

also a knocking noise

No successful repair reported for this finding.

1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
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.

Reported cause · Original poster

The second issue is also a knocking noise from the rear.

Quiet knocking noise
Coverage and how to read this overview

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.

15 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • 911uk: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261027T003124Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Hi all I have a couple of small niggles and looking for advice as I suppose they could be linked? My sunroof, when fully open makes a knocking noise over bumps - actually quite an agressive one. It's had a new motor, but feels like something isn't locking it into place when fully opened. If I close it an inch from fully opened the noise is 100% removed which is why I think it might be some type of support/click - any ideas would be amazing ( I have not removed the headlining yet, and if that is the route, I'll take it to a garage I think) The second issue is also a knocking noise from the rear. Car has new poly bushes throughout (c. 5k old) and new bilstein suspension, c. 5k old. Generally quite quiet over bumps, its around long corners like roundabouts, if I go from left to right I get a small clunk almost like a sliding clunk.... sometime reversing in a corner does the same and recently its getting more obvious on smaller corners. I checked the sway bars and tried to tighten with a wrench, but little to no movement. Any thoughts what I should be checking and tightening? Thanks as always!

POST 2Original post

On the rear it sounds like one of the eccentric bolts for the coffin arm/toe arm adjustment may not be tight. You can easy spot this as you can see where the bolt has been riding up and down in the subframe here:

POST 3 / ORIGINAL POSTEROriginal post

Thanks Alex - just checked - quite rusted and doesn't appear any movement.... Thanks again

POST 4 / ORIGINAL POSTEROriginal post

I did try and tighten and not possible so think rules this section out

POST 5Original post

Did you try both on that side? Coffin arm and toe arm?

POST 6 / ORIGINAL POSTEROriginal post

Morning Alex - yes tried both - the only thing I could seem to tighten were the sway arm bolts. I tried an impact wrench on the toe arm eccentric which didn't appear to move it. I think I might need to drop it by a garage to check it over.... Any other thoughts very much appreciated

POST 7Original post

There'll be play in an arm or a link. The only real way to diagnose it is to disconnect one side completely from the car and then try moving it and feel for any play. Likely candidates are the ball/socket joints on your coffin arm, toe arm, and the support arm that runs diagonally to the coffin arm.

POST 8 / ORIGINAL POSTEROriginal post

Interestingly, I went for a drive yesterday and tried some sharper left to right steerings at c. 50 mph and the knock is quite apparent - perhaps I've never really noticed due to mainly motorway - longer A roads. I've checked over the bushings and they still look clean and purple.... Thanks

POST 9Original post

As I said, it'll be a worn ball joint in one of the arms or drop link.

POST 10Original post

Quotes source post: 2688516

I concur, my 997 had covered 82.000 miles when I purchased it. A number of noises on cornering, they did not look it from visual inspection but a number of the rubber bushes in the coffin arms were toast. There have been cases of coffin arms giving up the ghost after a short mileage

POST 11Original post

Quotes source post: 2688521

Unlikely to be bushes as the OP is saying he has changed them to poly. Therefore these should now last forever. The ball joints can wear out and develop play but I don't know if they will clunk.

POST 12 / ORIGINAL POSTEROriginal post

Sorry for the slow response Alex, I broke my foot so energy has been spent trying to recover and completely forgot to respond. Thank you - I'll have to wait until it goes in for a service now I think.... thank you

POST 13 / ORIGINAL POSTEROriginal post

Hi Alex - just looking under the car again, and a friend has pointed out that the sway bar bushings look tired and quite dry. Would worn sway bar bushings cause a quiet knocking noise? Cheers

POST 14Original post

Yes they can do, but you can usually rattle your sway bar up and down and see the play if its them. To rule it out, an easy fix is to remove the bushing cover and remove it, remove the bush, wrap a few lengths of insulation (or other) tape around the bar to increase the diameter, then put it all back together. This will take any play up and you can take it for a test drive to see if its gone. Alex's free fix of the day

POST 15 / ORIGINAL POSTEROriginal post

Hi Alex - thought i'd update you on progess. I got the car up and rear wheel off - nothing loose at all, tried gentle tap with rubber mallet - all rock solid. So went around with a wrench to see if any bolts loose - the top coffin arms had approx 1/8th turn in them to c. 100 lbs. cant remember exacts..... The rear right drop link appeared the loosest nut and having looked online I saw the torque was c. 40 lbs but people say tighten them as much as possible. So I gave it a good tighten to c. 80/90 lbs - went for a drive a knocking largely gone however felt something from the left. Jacked up and repeated on the drop link, this one was very loose. (but like the right, not loose when trying to wiggle - but perhaps that's the issue when trying to work off of the floor) so tightened up and on my next outing I'll report back! Thanks again

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