So i changed fromt ARB bushings and control arm's with cupra bushings, now my 3-pot has horrid NVH when i pul from idle to ~1300rmp.

It shakes the entire car, over 1300rpm it goes smooth again and rides like a charm.

It also shakes like that if i engine brake under 1300rpm.

What could be the culprit? I have not done an alignment yet either.

 

Also the ARB bushings where ordered as 20mm and my ARB is 20mm, but the old bushings had a bigger internal diameter when i took em of, tho they did have 190.000km on them so maybe just worn down some?

 

1 hour ago, Truls84 said:

i changed fromt ARB bushings and control arm's with cupra bushings, now my 3-pot has horrid NVH

 

1 hour ago, Truls84 said:

What could be the culprit?

Harder ARB and control arm bushes.

Give it time new bushes need a bit to bed in. 

Older arb bushes were just wore out hence the larger size hole.

I changed my front bushes to Poly ones last year, vibration was unbearable - like yours mine is a diesel and the vibration transference to the cabin was horrid. Swapped them for OEM ones after a couple of days.

On 22/05/2022 at 21:40, Truls84 said:

What could be the culprit?

 

Deciding to ignore the benefits of decades and millions of pounds of NVH research and development that have gone into producing voided rubber to metal bonded bushes.

39 minutes ago, J.R. said:

 

Deciding to ignore the benefits of decades and millions of pounds of NVH research and development that have gone into producing voided rubber to metal bonded bushes.

Spot on  they dont just throw things on a car and hope for the best, they do things with a reason

 

Steady on with the tartan rug brigade.

 

Void bushes are designed to yield easily to promote understeer, manufacturers deem it safer with FWD cars to have such handling characteristics because most punters are terrible drivers who do stupid panicky things like braking mid-corner if it tightens up on them.

 

There are those of us who don't run with the herd who don't like a rubbery front end and prefer more precision in our steering and handling.

 

Driving isn't for everyone although everyone thinks they're good at it.

Void bushes are designed to be stiff in one direction and compliant in the other, I racked my brains but could not come up with the term for a material that does not have uniform strength in all directions.

 

I was a race car constructor and driver and would use solid mountings, polybushes, rose joints etc where they gave an improvement but it was always at the cost of NVH (no loss) and maintenance, any articulated joint using poly bushes would wear.

 

I have yet to find an application on a road vehicle where any benefit would outweigh the disadvantages, certainly on any articulated joint they lose all the benefits of a rubber to metal bonded bush, that of being maintenance free, if they at least had a grease nipple it would be a start for those willing to go back 50 years.

 

I would actually prefer a vehicle that had a more direct connection through the controls and would be happy having to grease all the joints every 6 weeks, when I use a digger I grease all the joints before and after use, but modern suspension designs, the console bushes being a good example could not operate without compliance using rose joints and solid bushes, electric power steering was the final nail in the coffin AFAIK regarding control feedback.

 

Over a decade ago I was driving an old beat up high mileage MK1 Octavia, for the Téléthon our Lycée pro (motor trade) would invite the public to have their vehicles checked over in the workshops then washed & valeted, my job was to drive the vehicles through the various stations, most were newish vehicles, nearly all newer and better condition than mine, normally it would have left me with a desire for something newer and better.

 

It was not the case at all, all of them were huge, heavy yet confined, no knee room, peering over a high dash, narrow slits for windows, bad visibility whilst I was driving through the narrow path between the stations, the worst of all was the total feeling of disconnection between the controls and the steering, suspension, brakes etc, the absolute highlight of the day was a basic 80's Renault 5 which was a total joy, light doors that closed properly with smooth manual window winders, superb visibility, loads of glass and narrow pillars, sublime non power assisted steering, brakes, clutch and handbrake.

 

The drive home made me realise that the dog that it was, my MK1 Octavia was a better drivers car than any of them, when I bought a MK2 I liked how familiar it was but hated the huge A & B pillars and most of all the electric power steering, people said that I would get used to it and very sadly indeed  I have but no amount of polybushes could make that or my current Yeti into the drivers car that the MK1 was, quite the opposite, I believe they would make it worse.

 

I have a clonk from the RH front suspension, it does not appear to be the new strut or top bearing nor the cheap drop links that I fitted so later on I will be checking all the suspension bushes, I will keep an open mind regarding poly bushes but only for any joints with a rotational element around the fixing bolt.

Alright @J.R., but I can categorically assure you that replacing console bushes with non-void bushes on the Fabia I is all killer and no filler, I've used Cupra rubber solids as well as PU and they're both great upgrades with no downsides.

 

The OP needs to look elsewhere for the source of the vibration problem.

I plan to replace the voided TCA rear bushes with non voided ones - when the need/time comes, but that is on a Polo 1.2TSI, many many years back, when people had just started to need to replace the console bushes in their Fabia/Polo/Ibizas, someone, probably Ross,  issued a cautionary warning concerning NVH issues when fitting the Cupra non voided console bushes to cars with TDI engines, I got them fitted to my wife's 2002 Polo with the 1.4 75PS BBY petrol engine when the original voided console bushes ended up getting torn, and everything was positive absolutely no extra unwanted NVH issues, just sorted out console bushes along with much increased feeling from steering inputs.

Edited 28 May, 20224 yr by rum4mo

I'm changing back to normal bushes and having an aligment done after that. If it wasn't for the NVH i would have kept them, i like some of the characteristics of them better. I just didn't imagine that the control arm bushes would transfer engine noise, i only seen warnings about harder engine mounts doing so.

On 28/05/2022 at 16:15, sepulchrave said:

Alright @J.R., but I can categorically assure you that replacing console bushes with non-void bushes on the Fabia I is all killer and no filler, I've used Cupra rubber solids as well as PU and they're both great upgrades with no downsides.

 

The OP needs to look elsewhere for the source of the vibration problem.

was your car a 3 cylinder?

6 hours ago, Truls84 said:

was your car a 3 cylinder?

 

No, both fours.

Just posting incase someone else get the same problem.

Changed to some new normal control arm bushings and the car is back to normal.

Lesson for today, if you have a 3-cylinder do not change to cupra or poly bushes on the control arm or the engine mount unless you want a rough ride when the engine is under 2000rpm.