Wanted: bit of special help please
- Thread starter 911hillclimber
- Start date
I'm trying to find an obvious reason for this as you know Rob, and the 'nature' of the hum at such precise speeds for the last 3 or 4 years now do not point to bearing wear and such like which over the miles would have become ever louder I think.
This all started suddenly in Austria on a tour in the car 4 years back. 2 things happened in one day.
1
The engine went on 5 cylinders when really hot. We had been in a very slow traffic jam on a hot day. Pulled off to a parking area and waited.
Reversed to a spot and there was a crunch, as if i had driven slowly to a curb. The parking area was 'rustic' and no defined curbs but rough.
15 mins later he engine was on 6 for 20 mins then 5 until we got to the hotel. Another short story but RAC Cover fixed it in a few hours(!), I had a spare plug top with me!
2
The hum was ever present from that incident on to today.
Last MoT at Zuffenhaus and the broken air duct was found wedged between the gearbox and the chassis. It was pulled out, mostly intact. This must have been what cracked on that car park in Austria.
I swear the car was far quieter on the way home...but not fully gone.
Repaired and re-installed the plastic duct as you saw on your ramp, but the noise, still better, persisted.
When the weather breaks I'll jack the car up and try to see if the leading underbody panel are in place but I think they are.
Zuffenhaus removed them to do the front cross-over pipes last year and replaced them but the noise persisted, the MoT followed. This was March 2026.
I can find nothing on the internet that might explain this noise.
This all started suddenly in Austria on a tour in the car 4 years back. 2 things happened in one day.
1
The engine went on 5 cylinders when really hot. We had been in a very slow traffic jam on a hot day. Pulled off to a parking area and waited.
Reversed to a spot and there was a crunch, as if i had driven slowly to a curb. The parking area was 'rustic' and no defined curbs but rough.
15 mins later he engine was on 6 for 20 mins then 5 until we got to the hotel. Another short story but RAC Cover fixed it in a few hours(!), I had a spare plug top with me!
2
The hum was ever present from that incident on to today.
Last MoT at Zuffenhaus and the broken air duct was found wedged between the gearbox and the chassis. It was pulled out, mostly intact. This must have been what cracked on that car park in Austria.
I swear the car was far quieter on the way home...but not fully gone.
Repaired and re-installed the plastic duct as you saw on your ramp, but the noise, still better, persisted.
When the weather breaks I'll jack the car up and try to see if the leading underbody panel are in place but I think they are.
Zuffenhaus removed them to do the front cross-over pipes last year and replaced them but the noise persisted, the MoT followed. This was March 2026.
I can find nothing on the internet that might explain this noise.
Mx5 is a good shout for a replacment if sticking with a cab.
They just dont go wrong wife had a very early one for 4 years used daily never any problems
Couple of services thats it.
But of course in any car you can get the Friday afternoon car i can vouch for that we had one spent more time in the garage than on the road one thing after another some serious repairs also.
Had to go in the end.
They just dont go wrong wife had a very early one for 4 years used daily never any problems
Couple of services thats it.
But of course in any car you can get the Friday afternoon car i can vouch for that we had one spent more time in the garage than on the road one thing after another some serious repairs also.
Had to go in the end.
My daughter has has 4 x MX5's. Loved them all and someone rear ended one to a right-off, but no injuries, got out through the roof. Last on was an RF 1500 which was slow.
She loved the Mk2's the most.
One big issue, very small boot space, no good for 10 days in Europe....
The use of the sports car is down to practicality, and the 2 boots in the Boxster make it very hard to compare with anything else.
TBH, if the Boxster goes we will drop the 'Sports Car' , hard to justify.
Shame about this hum issue, the car is great otherwise but at 92K miles getting into the danger zone of clutches etc, all original and all working well.
Other justification is it could become the hillclimb car as it is if we have to drop the Lola hillclimb car. (wife's idea).
She loved the Mk2's the most.
One big issue, very small boot space, no good for 10 days in Europe....
The use of the sports car is down to practicality, and the 2 boots in the Boxster make it very hard to compare with anything else.
TBH, if the Boxster goes we will drop the 'Sports Car' , hard to justify.
Shame about this hum issue, the car is great otherwise but at 92K miles getting into the danger zone of clutches etc, all original and all working well.
Other justification is it could become the hillclimb car as it is if we have to drop the Lola hillclimb car. (wife's idea).
Rob: just sent pm ref the hum.
Graham.
Graham.
Possibly some PROGRESS at last.
Removed the front cover shield off the nose of the car. Now I know why people remove these shields from the rear first, all the linking tabs are designed to hook into the front, then the middle(3) and then the rear cover.
Not easy to get the front off with the middle in place, damage almost certain and mine was damaged!
2 of the Torx screws were toast, but got them all out after a good struggle on my back with car on stands, wheels off.
Anyway, took the car for a run with the wife (hearing of a fruit bat) and the noise has all but GONE.
Came back and repaired the broken tab that stops the large front panel from 'panting'. It could be moved a good inch up and down.
A 80 x 60 piece of 2mm alum alloy sheet with 6 good pan head pop rivets and my fav glue by Gorilla and the panel is now setting, back on tomorrow.
This feature (a plastic tab) is very vulnerable when stressing the plastic panel into place, not looking forward to testing my repair.
At the factory, the tab would slide in nicely and the middle 3 panels link well etc.
When it is on, I will tape over all the gaps on the edges that air would pass into the body underside, so I hope to seal it off, gorilla to the cause again, very hi-tac tape.
Acid test test drive after, hopefully tomorrow/Saturday.
Rob, we might be right yet!
Removed the front cover shield off the nose of the car. Now I know why people remove these shields from the rear first, all the linking tabs are designed to hook into the front, then the middle(3) and then the rear cover.
Not easy to get the front off with the middle in place, damage almost certain and mine was damaged!
2 of the Torx screws were toast, but got them all out after a good struggle on my back with car on stands, wheels off.
Anyway, took the car for a run with the wife (hearing of a fruit bat) and the noise has all but GONE.
Came back and repaired the broken tab that stops the large front panel from 'panting'. It could be moved a good inch up and down.
A 80 x 60 piece of 2mm alum alloy sheet with 6 good pan head pop rivets and my fav glue by Gorilla and the panel is now setting, back on tomorrow.
This feature (a plastic tab) is very vulnerable when stressing the plastic panel into place, not looking forward to testing my repair.
At the factory, the tab would slide in nicely and the middle 3 panels link well etc.
When it is on, I will tape over all the gaps on the edges that air would pass into the body underside, so I hope to seal it off, gorilla to the cause again, very hi-tac tape.
Acid test test drive after, hopefully tomorrow/Saturday.
Rob, we might be right yet!
Good news some progress made, all but gone still sounds like not 100% .
Very surprised a good indie has never got to the root of this issue.
Glad you might be on the right track at last.
All the best with a future resolve 100%
Very surprised a good indie has never got to the root of this issue.
Glad you might be on the right track at last.
All the best with a future resolve 100%
Yes, I think there is a bit still there, but nowhere near as prominent as before.
Rob's suggestion was to remove all the shields and then see if it is all gone. Not an easy task on stands on your back, but tempted.
If that was the case, the shields have to be re-installed, so a full circle.
I'm hoping the fixed location of the shield and the tape over the gaps will get rid of that last bit.
At the risk of repeating myself in this very long running saga, the noise I get, the Hum, does not have any vibration to be felt when it is chimed in, particularly at 54/56 mph, it is all sound and not like things are touching each other where vibration would accompany the noise.
When I test drove the car with Rob's wheels on the other day the hum was very apparent, today, 5% if that at the same speed, much the same unbroken road surface.
This is a low level hum, constant, and if you get it in your head you really notice it. Today I was really trying to hear it.
More so, my wife did not say it had gone during today's test but it was quieter and different in nature.
Noise is a difficult issue.
Rob's suggestion was to remove all the shields and then see if it is all gone. Not an easy task on stands on your back, but tempted.
If that was the case, the shields have to be re-installed, so a full circle.
I'm hoping the fixed location of the shield and the tape over the gaps will get rid of that last bit.
At the risk of repeating myself in this very long running saga, the noise I get, the Hum, does not have any vibration to be felt when it is chimed in, particularly at 54/56 mph, it is all sound and not like things are touching each other where vibration would accompany the noise.
When I test drove the car with Rob's wheels on the other day the hum was very apparent, today, 5% if that at the same speed, much the same unbroken road surface.
This is a low level hum, constant, and if you get it in your head you really notice it. Today I was really trying to hear it.
More so, my wife did not say it had gone during today's test but it was quieter and different in nature.
Noise is a difficult issue.
Back to Square 1.
Removed and repaired the front undertray, but a drive with it off had the noise down substantially.
All back on and tape over the gaping holes and slots.
Drive today and the noise is full back.
Obviously have to have the front shield on.
Plan now is to remove the under shield from the rear forward to the front, test driving after each one is removed.
Starting with the dearbox vents which started all this off, drive it. If still there the rear shield (quite small)) and drive it etc until just the front on.
If the noise is still there the aero theory is done for and we are back to bearings etc.
Booked in at Zuffenhaus20 Aug for a check by them.
Getting close to selling and forget modern sports cars.
Removed and repaired the front undertray, but a drive with it off had the noise down substantially.
All back on and tape over the gaping holes and slots.
Drive today and the noise is full back.
Obviously have to have the front shield on.
Plan now is to remove the under shield from the rear forward to the front, test driving after each one is removed.
Starting with the dearbox vents which started all this off, drive it. If still there the rear shield (quite small)) and drive it etc until just the front on.
If the noise is still there the aero theory is done for and we are back to bearings etc.
Booked in at Zuffenhaus20 Aug for a check by them.
Getting close to selling and forget modern sports cars.
That’s rather disappointing news Graham, and somewhat disheartening for you too I’m sure.
However, at least you’re eliminating potential sources and hopefully progressing towards a solution. As you say, having started on the path it’s sensible progressively to keep removing the undershields to see if that has any effect and if not then you have to look elsewhere, presumably the rear wheel bearings/driveshafts, and the involvement of Zuffenhaus seems like a sensible course of action.
You mentioned that the problem appeared to occur suddenly after your “reversing incident” in Austria, so maybe you should pay particular attention to the rear underside even though you’ve visited that area previously?
I know from experience that tracing the source of sound and vibration issues can be extremely time-consuming and frustrating and hope that eventually you’ll crack it and wish you well.
Jeff
However, at least you’re eliminating potential sources and hopefully progressing towards a solution. As you say, having started on the path it’s sensible progressively to keep removing the undershields to see if that has any effect and if not then you have to look elsewhere, presumably the rear wheel bearings/driveshafts, and the involvement of Zuffenhaus seems like a sensible course of action.
You mentioned that the problem appeared to occur suddenly after your “reversing incident” in Austria, so maybe you should pay particular attention to the rear underside even though you’ve visited that area previously?
I know from experience that tracing the source of sound and vibration issues can be extremely time-consuming and frustrating and hope that eventually you’ll crack it and wish you well.
Jeff
Yes, right at the bottom of this endless sine wave with this car. Have to remember how good a car it is!
There is only one thing wrong with it, and it's this noise.
I hope Zuffenhaus might find something in a few weeks time.
Meanwhile, the car just runs so well, so if it is the tyres (say) then I'll just keep on grinding away until I have to have new fitted.
The fronts are 2016, were fitted 'new' when they were actually 2 or 3 years old.
Rears are 2023.
Trish recalls the noise suddenly arrived while touring in Austria 4 years ago and has been the very same since.
There is only one thing wrong with it, and it's this noise.
I hope Zuffenhaus might find something in a few weeks time.
Meanwhile, the car just runs so well, so if it is the tyres (say) then I'll just keep on grinding away until I have to have new fitted.
The fronts are 2016, were fitted 'new' when they were actually 2 or 3 years old.
Rears are 2023.
Trish recalls the noise suddenly arrived while touring in Austria 4 years ago and has been the very same since.
Sorry to hear so frustrating
Indeed. I've had a few teasers along my considerable years of tinkering with cars, but this one is in the top 5.
All Shiels back on, cleaned etc. Doubt Zuffenhaus will have ever seen such clean shields on a 92K mile Boxster !
There were no marks on the inside face of the shields, ie no evidence of rubbing, no contact points.
No pipes loose or having too much 'freedom'
Taking Jeffs point to surgically examine the area of contact some 4 years ago in Austria, everything is clear.
When I worked in automotive in the late 80's the general rule of thumb was to have one finger diameter between adjacent parts. My work was inside doors, so clearances between window regulators, looms and all that was carefully assess. My finger is quite sore now...
Trish and I have now reached the conclusion:
Car runs great, all works, so we will simply tour in it and ignore the noise.
The front tyres need changing due to age, in 7 years they are 2/3rds worn, about 20K miles on them. Shows how easy a life this car has had with us.
We will change the 4 tyres soon to Michelin Sport 4S and see.
Looking around what other car could take the Boxster's place...well that is quite a question.
The package is so good in a Boxster.
Maybe a simple AUDI TT gets close.
They look easy to live with, several will have had good owners and i like the pre-facelift original design.
My daughter had one and loved it but a face lift.
I feel I've hogged this forum too much to the point of Reader Boredom, so will come back if we get rid of the noise or the car!
We Buy Any Car are offering nearly £10K unseen, so that will be the part ex value to work on.
Thank you for everyone's help.
All Shiels back on, cleaned etc. Doubt Zuffenhaus will have ever seen such clean shields on a 92K mile Boxster !
There were no marks on the inside face of the shields, ie no evidence of rubbing, no contact points.
No pipes loose or having too much 'freedom'
Taking Jeffs point to surgically examine the area of contact some 4 years ago in Austria, everything is clear.
When I worked in automotive in the late 80's the general rule of thumb was to have one finger diameter between adjacent parts. My work was inside doors, so clearances between window regulators, looms and all that was carefully assess. My finger is quite sore now...
Trish and I have now reached the conclusion:
Car runs great, all works, so we will simply tour in it and ignore the noise.
The front tyres need changing due to age, in 7 years they are 2/3rds worn, about 20K miles on them. Shows how easy a life this car has had with us.
We will change the 4 tyres soon to Michelin Sport 4S and see.
Looking around what other car could take the Boxster's place...well that is quite a question.
The package is so good in a Boxster.
Maybe a simple AUDI TT gets close.
They look easy to live with, several will have had good owners and i like the pre-facelift original design.
My daughter had one and loved it but a face lift.
I feel I've hogged this forum too much to the point of Reader Boredom, so will come back if we get rid of the noise or the car!
We Buy Any Car are offering nearly £10K unseen, so that will be the part ex value to work on.
Thank you for everyone's help.
If you keep it turn the sound system up and ignore it other wise it will drive you insane.
You have tried its one of those things.
I assume you have changed the gearbox oil along the way.
Not at all you have hogged the forum iam sure we all hope for a solution for you.
Good luck let us know the eventual outcome if there is one.
Cliff.
You have tried its one of those things.
I assume you have changed the gearbox oil along the way.
Not at all you have hogged the forum iam sure we all hope for a solution for you.
Good luck let us know the eventual outcome if there is one.
Cliff.
The problem with noise issues is that once heard you can’t unhear them Graham!
In one respect I agree with Cliff in that - as with tinnitus sufferers - really you need something to distract you if you plan try to ignore the noise and just use the car as normal because ATM you’re very focused on it, and maybe a suitable selection of music will help.
If eventually you decide to move the car on I’d be inclined to do it through a Porsche specialist rather than the usual WBAC, etc., channels who are more interested in the volume market. It’ll be worth asking Zuffenhaus for a valuation when the car’s with them and I’m sure that an Audi TT would prove to be a decent replacement for the Boxster.
Like Cliff - and no doubt others on here - I’ve enjoyed reading about your journey, frustrating though it’s been for you, and have tried to make some useful suggestions along the way even if they weren’t successful, and I hope that eventually you reach a satisfactory solution to the problem.
Keep us posted on progress.
Jeff
In one respect I agree with Cliff in that - as with tinnitus sufferers - really you need something to distract you if you plan try to ignore the noise and just use the car as normal because ATM you’re very focused on it, and maybe a suitable selection of music will help.
If eventually you decide to move the car on I’d be inclined to do it through a Porsche specialist rather than the usual WBAC, etc., channels who are more interested in the volume market. It’ll be worth asking Zuffenhaus for a valuation when the car’s with them and I’m sure that an Audi TT would prove to be a decent replacement for the Boxster.
Like Cliff - and no doubt others on here - I’ve enjoyed reading about your journey, frustrating though it’s been for you, and have tried to make some useful suggestions along the way even if they weren’t successful, and I hope that eventually you reach a satisfactory solution to the problem.
Keep us posted on progress.
Jeff
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