Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Ironingboard on 18 April 2008, 21:18:55

Title: Crapped myself
Post by: Ironingboard on 18 April 2008, 21:18:55
Ok I'm looking for some ideas to what caused a god awful sound I heard while driving.

Was coming down a hill while in D mode in my Omega was doing about 20 mph, dropped it to 1 to do some engine braking, then put my foot on the throttle to accelerate away quickly and all of a sudden I heard a loud thump thump thump. Scared the crap out of me, released the accelerated and moved it back into D.

Any ideas in what it could be folks?
Title: Re: Crapped myself
Post by: bustedomega on 18 April 2008, 21:20:08
does the car drive ok now??
Title: Re: Crapped myself
Post by: Andy B on 18 April 2008, 21:22:25
Quote
Ok I'm looking for some ideas to what caused a god awful sound I heard while driving.

Was coming down a hill while in D mode in my Omega was doing about 20 mph, dropped it to 1 to do some engine braking, then put my foot on the throttle to accelerate away quickly and all of a sudden I heard a loud thump thump thump. Scared the crap out of me, released the accelerated and moved it back into D.

Any ideas in what it could be folks?

You must think there's a clairvoyant somewhere here!  ;D
Where abouts is the thump coming from? Front of the car? Middle? Back? nearside? Offside? Heavy thump? Light thump? Metalic? etc etc
Title: Re: Crapped myself
Post by: Ironingboard on 18 April 2008, 21:22:29
Yeah its fine, its only when I do some quick manual gear changes that I get the sound from the back of my car.
Title: Re: Crapped myself
Post by: Marks DTM Calib on 18 April 2008, 21:59:15
Does it have an LSD?

It could be axle tramp if the rear shocks are a little tired.
Title: Re: Crapped myself
Post by: VXmega on 18 April 2008, 23:29:39
Hi..... Had some thing very much like this to happen me but it was on my Senator ...... anyway turned out to be the centre bearing in the prop..... starts of when your giving it a good bit of wellie from rest or low speed after short period pretty much every time your moving off......... prop tries to hit the floor when under load ..........
Regards
Title: Re: Crapped myself
Post by: Andy B on 19 April 2008, 00:01:53
Quote
Hi..... Had some thing very much like this to happen me but it was on my Senator ...... ....

Mine was the big bushs in the rear sub frames.
Title: Re: Crapped myself
Post by: ffcgary1 on 19 April 2008, 00:42:42
Is it a good idea to put the car into 1 from d whilst the car is driving at speed or is this ok on an auto? I ask this as a manual box driver, although i had an auto granny 2.8 with a c3 box fitted. I very rarely used anything other than p,r d on mine. :-?
Title: Re: Crapped myself
Post by: JonArgraig on 19 April 2008, 00:45:07
TBH, for normal driving if I need a little engine braking I just hit the sports mode button, I never get why some people buy a auto and still feel the need to keep changing gear :)

well each to there own I guess

But I would guess the big bushes on the back end, or the main prop bearing
Title: Re: Crapped myself
Post by: Andy B on 19 April 2008, 01:03:04
Quote
Is it a good idea to put the car into 1 from d whilst the car is driving at speed or is this ok on an auto?  ........

The theory is that if you're going too fast for a particular gear position ie 1 at 70mph, the gearbox won't actually go into that gear. It's not something I've ever tested. :o :y
Title: Re: Crapped myself
Post by: Ironingboard on 19 April 2008, 01:54:47
Quote
Quote
Is it a good idea to put the car into 1 from d whilst the car is driving at speed or is this ok on an auto?  ........

The theory is that if you're going too fast for a particular gear position ie 1 at 70mph, the gearbox won't actually go into that gear. It's not something I've ever tested. :o :y

Yeah I read the same thing Andy  :y

I've changed the rear sub frame bushes, would those be the triangle shaped ones near the differential?

I don't think its got an LSD

How do you check the prop bearings, does the prop move around near the bearing when their worn???
Title: Re: Crapped myself
Post by: Andy B on 19 April 2008, 02:07:07
Quote
......
I've changed the rear sub frame bushes, would those be the triangle shaped ones near the differential?
No. They're on the outside edges of the car just infron tof the rear wheels. I've never actually donean Omega's but a Senators are about 5"dia & a couple of inches thick with a steel centre 'tube'


Quote
How do you check the prop bearings, does the prop move around near the bearing when their worn???
Yes  ;D But I think it'd have to be completely oppsed for you to feel it that much in the car.
Title: Re: Crapped myself
Post by: Ironingboard on 19 April 2008, 02:28:44
Quote
Quote
......
I've changed the rear sub frame bushes, would those be the triangle shaped ones near the differential?
No. They're on the outside edges of the car just infron tof the rear wheels. I've never actually donean Omega's but a Senators are about 5"dia & a couple of inches thick with a steel centre 'tube'


Quote
How do you check the prop bearings, does the prop move around near the bearing when their worn???
Yes  ;D But I think it'd have to be completely oppsed for you to feel it that much in the car.

Yeah I've changed those bushes as well  ::)

I dont have a vibration in the car at any speed, so I don't think its the prop bearings, but somethings not right with the thump sound, there's goto be something moving that shouldn't be.
Title: Re: Crapped myself
Post by: waspy on 19 April 2008, 09:48:56
I can relate to this problem you have. I've had countless SD1's in the past & these where renowned for the props on Auto's cluncking. This would be the first place i'd go for. HTH
Title: Re: Crapped myself
Post by: Ironingboard on 19 April 2008, 09:59:31
Quote
I can relate to this problem you have. I've had countless SD1's in the past & these where renowned for the props on Auto's cluncking. This would be the first place i'd go for. HTH

Where should I look at on the prop to fix this problem?
Title: Re: Crapped myself
Post by: VXmega on 19 April 2008, 19:58:29
Quote
Quote
I can relate to this problem you have. I've had countless SD1's in the past & these where renowned for the props on Auto's cluncking. This would be the first place i'd go for. HTH

Where should I look at on the prop to fix this problem?


Grab the prop either side of the centre bearing and see what the movement is like you'll soon know......... the rubber on mine was well goosed and supporting nothing but only thumped on pulling away ...... never when driving along

regards
Title: Re: Crapped myself
Post by: waspy on 19 April 2008, 20:01:14
Quote
Quote
Quote
I can relate to this problem you have. I've had countless SD1's in the past & these where renowned for the props on Auto's cluncking. This would be the first place i'd go for. HTH

Where should I look at on the prop to fix this problem?


Grab the prop either side of the centre bearing and see what the movement is like you'll soon know......... the rubber on mine was well goosed and supporting nothing but only thumped on pulling away ...... never when driving along

regards

 :y :y :y