2006 octavia 4x4 "resonates" under load @ 23-2500rpm

[lacrits68]

hello!

 

My scoda has deveoped an "nasty" habit. it makes a "resonating" noise under acceleration 23-2500rpm. i does not vibrate its more like the whole car is a big resonating chamber. 

I cant fins any obvious fault, passed MOT and so on.

 

any ideas what to look for?

 

//Jan

 

 

[phoneman(ret)]

Hi Jan,

 

My car does the same ! mainly in 5th or 6th gear at around 2200 RPM. It has gradually got worse over a number of years - useful for keeping to 70 MPH limit on motorways though as it occurs at around 75 MPH in 6th gear ! Have been told that the fault is the couplings on the prop-shaft ( 4 wheel drive Scout) but it would cost a LOT of money to fix. If your car is not a 4x4, sorry I haven't been much help.

 

Cheers,

Lloyd

[skomaz]

This is definitely the rearmost propshaft rubber doughnut coupling failing.  Cost is about £100 for the coupling alone from various suppliers but Skoda will only sell you a full propshaft at about £800 all plus fitting. 

[J.R.]

There are a few parameters in VCDS with various mistranslated names which are for transmission noise reduction at various RPM ranges, all of which had values programmed in by the factory on my vehicle, I think they reduce the Haldex engagement or even decouple it at resonant frequencies, there are different ones for petrol and diesel engined variants.

 

I have also seen log scans showing the Haldex engagement reduced or removed at certain RPM ranges.

 

I conclude that resonance was a problem in service not designed out by the NVH engineers and the parameters were introduced as a very crude sticking plaster because the Guibo coupling was not performing as intended.

Edited 15 September, 2022 by J.R.

[lacrits68]

good morning all!

 

thank you all for replyes.

 

Quote

Cost is about £100 for the coupling alone from various suppliers 

 

 what might this part have a number and where to get it? do I need just the "donut", do it come as "kit"? or do I need more parts to replace it?

 

on more thing, can I drive the car or is it unsafe when risk to "donut to fail"? Im a bit from nearest garage.

 

//Jan

Edited 16 September, 2022 by lacrits68

[lacrits68]

hello!

 

1 more thing car is an 2006 with vin if this helps TMBKS61Z268066966 

[skomaz]

Yep you should be fine to drive it but it will get worse over time - we did about 30,000 miles in ours between it starting faintly and us finally getting rid of it when various issues meant the cost of repair was higher than the value of the car.

 

The post below should help:

 

 

Edited 16 September, 2022 by skomaz