Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: opelman on 14 June 2019, 21:55:11

Title: Sound / howl sound from drive on opel omega b 2.5v6
Post by: opelman on 14 June 2019, 21:55:11: Hi
I have an old opel omega b 2.5v6, which has got really bad in the drive. it is a howl sound and it comes at approx. 40km / h. at 70km / h it gets almost gone, then it gets up by approx. 80km / h.
I have changed wheel bearings at the back. There is no surrender if one turns. the sound is constant.
what could it be? :-[
Title: Re: Sound / howl sound from drive on opel omega b 2.5v6
Post by: BazaJT on 15 June 2019, 08:39:46: Differential? Although I don't know if the sound would alter when turning or not.
Title: Re: Sound / howl sound from drive on opel omega b 2.5v6
Post by: dave the builder on 15 June 2019, 11:07:20: This needs methodical diagnosis, and more information needed , what work has been done,how many miles/Km has the car done :-\ auto or manual box ???
could be many things, diff noise is very possible
also prop center bearing, wheels out of balance, worn front or rear suspension (out of line) is there un-even tyre wear :-\
clutch and flywheel issue, sticking brakes is unlikely at such speed
can't rule out things like a window slightly open, wheel arch plastic liner or trim loose (resonates with speed) exhaust issue
lots of possibilities :(
Title: Re: Sound / howl sound from drive on opel omega b 2.5v6
Post by: Entwood on 15 June 2019, 11:26:30: When I was trying to diagnose a strange drive train noise I jacked the car up at the back onto very solid axle stands, then jacked the wheels to "level" using the lower shock absorber mounts, then ran the engine in gear. This enabled the drive train to function in "normal" aligenment, and it became very obvious that my problem was the diff. Far easier way of checking than trying to stick a head out of a window and listen !! :)
Title: Re: Sound / howl sound from drive on opel omega b 2.5v6
Post by: olm on 15 June 2019, 14:24:37: Check the center bearing
Title: Re: Sound / howl sound from drive on opel omega b 2.5v6
Post by: Doctor Gollum on 15 June 2019, 14:28:23: Prop bearing is pretty robust, even if abused. The diff however will wail like a scorned banshee if all the oil has dripped out over the last 15-20 years...
Title: Re: Sound / howl sound from drive on opel omega b 2.5v6
Post by: Nick W on 15 June 2019, 20:50:53: Quote from: Doctor Gollum on 15 June 2019, 14:28:23
Prop bearing is pretty robust, even if abused. The diff however will wail like a scorned banshee if all the oil has dripped out over the last 15-20 years...

I 'topped up' my diff when I had the car jacked for new rear shocks. It took a litre of hypoid :o and was much quieter for it.
Title: Re: Sound / howl sound from drive on opel omega b 2.5v6
Post by: opelman on 17 June 2019, 17:18:40: Hello again
I can tell a little about the car, it's a 1996 Opel omega B 2.5v6 estate, with manual gearbox that has gone 485000 km. I have, as I said, changed the wheel bearings behind, I have also changed the oil on the diff. The diff is a LSD diff. :)
Title: Re: Sound / howl sound from drive on opel omega b 2.5v6
Post by: Auto Addict on 19 June 2019, 07:37:37: Air vent blocked? Right hand Rear wheel arch inside boot?
Title: Re: Sound / howl sound from drive on opel omega b 2.5v6
Post by: opelman on 28 June 2019, 18:17:09: Hi again
I've figured out the noise, it was worn pinion stock. :-\