Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Vega on 18 August 2014, 18:36:59

Title: Vibration at 20km/h (12mi/h)
Post by: Vega on 18 August 2014, 18:36:59
I need some help with a strange phenomenon.


I have a Omega 2.6 (automatic) 2002 estate and when I start driving there is a vibration at 20 km/h (about 12 mi/h).
I test drove several 2.6 / 3.2 (automatic) saloons and estate and some of then does have the same vibration.

Anyone familiar with this vibration and does anyone know a solution.

Peter
Title: Re: Vibration at 20km/h (12mi/h)
Post by: 05omegav6 on 18 August 2014, 19:46:46
One or both rubber donuts on the propshaft starting to fail :-\
Title: Re: Vibration at 20km/h (12mi/h)
Post by: Vega on 18 August 2014, 21:20:51
Already replaced for other ones, no change.
Title: Re: Vibration at 20km/h (12mi/h)
Post by: tunnie on 18 August 2014, 22:51:54
Steering lock make a diffence? Limited slip diff oil?
Title: Re: Vibration at 20km/h (12mi/h)
Post by: Vega on 19 August 2014, 17:05:02
No LSD, just standard diff with new oil.

Steering lock make a diffence?

Explain?

Title: Re: Vibration at 20km/h (12mi/h)
Post by: minifreek on 19 August 2014, 18:17:46
Propshaft out of balance..?
Title: Re: Vibration at 20km/h (12mi/h)
Post by: Andy B on 19 August 2014, 18:35:39
No LSD, just standard diff with new oil.

Steering lock make a diffence?

Explain?

I think he means does it still do it if you have the steering wheel turned all the way to the left or right? Does it do it when driving in a straight line or just when you are turning?
Title: Re: Vibration at 20km/h (12mi/h)
Post by: Vega on 19 August 2014, 20:55:32
Propshaft out of balance..?

Tried different ones, no change.

I think he means does it still do it if you have the steering wheel turned all the way to the left or right? Does it do it when driving in a straight line or just when you are turning?

Doesn't matter, left right straight is always there around 20km/h.
Title: Re: Vibration at 20km/h (12mi/h)
Post by: 05omegav6 on 19 August 2014, 21:41:33
Scratch that ::)

Cracked flywheel :-\

Is it road speed related or engine speed? I know the transmission is most likely in first at that speed regardless, so is it present at the same engine rpm if revved in neutral?

Might help isolate the problem from the gearbox/propshaft/diff :-\
Title: Re: Vibration at 20km/h (12mi/h)
Post by: chrisgixer on 19 August 2014, 22:34:21
I'm wondering if he means the change up into second on an auto....? It's quite pronounced if off the throttle. Bit if a thump. They all do it.


Its a singular thump though, rather than a repetitive vibration like wheel balance issues....?
Title: Re: Vibration at 20km/h (12mi/h)
Post by: 05omegav6 on 19 August 2014, 22:41:53
Initial post suggests that it only affects some cars :-\

I forget who it was had a cracked flywheel, as discovered by Daz :-\ I also forget the symptoms, and obviously that one was totally shot, practically two pieces iirc :-\
Title: Re: Vibration at 20km/h (12mi/h)
Post by: Steve B on 19 August 2014, 22:45:06
I'm wondering if he means the change up into second on an auto....? It's quite pronounced if off the throttle. Bit if a thump. They all do it.


Its a singular thump though, rather than a repetitive vibration like wheel balance issues....?
Thought it was just mine  :-\ :-\
Title: Re: Vibration at 20km/h (12mi/h)
Post by: Vega on 20 August 2014, 08:58:54
Cracked flywheel :-\

No, changed that with the autobox with new oil 3 times. No change.

Quote
Is it road speed related

Only road speed, around 20km/h

Quote
Might help isolate the problem from the gearbox/propshaft/diff :-\

Tried 3 different propshafts and different rubber donuts, 2 diff's, no change

Tried different wheels all balanced, no change.

Initial post suggests that it only affects some cars :-\

Only the Omega's that I test drove, there could be more but I know that there are without the vibration.
Title: Re: Vibration at 20km/h (12mi/h)
Post by: ronnyd on 20 August 2014, 09:24:31
I'm wondering if he means the change up into second on an auto....? It's quite pronounced if off the throttle. Bit if a thump. They all do it.


Its a singular thump though, rather than a repetitive vibration like wheel balance issues....?
Thought it was just mine  :-\ :-\
Me to. :-[
Title: Re: Vibration at 20km/h (12mi/h)
Post by: 05omegav6 on 20 August 2014, 09:40:22
Engine/gearbox mounts still intact?
Title: Re: Vibration at 20km/h (12mi/h)
Post by: terry paget on 20 August 2014, 09:58:41
If you coast along at 25kph in neutral, does it gradually come in at 20kph, and fade away by 15kph?
Title: Re: Vibration at 20km/h (12mi/h)
Post by: Vega on 20 August 2014, 16:10:47
Engine/gearbox mounts still intact?

Yes

If you coast along at 25kph in neutral, does it gradually come in at 20kph, and fade away by 15kph?

Yes
Title: Re: Vibration at 20km/h (12mi/h)
Post by: 05omegav6 on 20 August 2014, 16:27:25
Engine/gearbox mounts still intact?

Yes

If you coast along at 25kph in neutral, does it gradually come in at 20kph, and fade away by 15kph?

Yes
What happens if you do this stationary in neutral and also in park?