Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: laughjimbo on 11 May 2007, 15:09:27

Title: dull knocking noise from rear
Post by: laughjimbo on 11 May 2007, 15:09:27
Hi Guys,
I have just replaced the rear shocks on my MV6 Saloon as they were getting really tired. I got a garage to do it and I got hold of some sachs gas ones, they are not the self levelling ones as my car has not got that feature but since they were fitted i have been getting a sort of dull knocking sound coming from the rear when i go over small bumps and it is really annoying. I have also got this creaking sound when i either go round corners or driving on and off my my driveway coming from just behind the drivers side rear passenger seat but the dull noise has only come about since the new shocks. The garage also told me that they checked all the rear bushes as i asked them and they were all ok. The car has only donw about 1000 miles since its last MOT which it passed with no problems.
Can anyone help please????
Thanks in advance!!

Jimbo
Title: Re: dull knocking noise from rear
Post by: ClarCE on 11 May 2007, 15:20:12
I don't know if this would be it, but has one of your rear coil springs broken up?  Changing the shocks might have exerted some new forces on one or both of them and caused one to break, might explain the knocking and they are prone to breaking on the Omega..
Title: Re: dull knocking noise from rear
Post by: mv6copcar on 11 May 2007, 21:57:23
tell you what-i had the same problem on my saloon,didn't have the shocks or anything changed at all, it just started knocking and got worse.
1)changed all 4 springs,
2)changed rear shocks
3)changed all rear bushes and anit-roll bar
4)-never guess what it was in the end...........

The N/S rear door latching pin (it bolts to the rear wheel arch to hold the door closed) had become loose and moved,thus the door sounded like it was closeing fine,but as the car bounced around the road the door lock and latching pin were banging against eachother. causing a very annoying dull(but solid sounding) knocking.

T45 bit, minor adjustment - job done, have a look  :y
Title: Re: dull knocking noise from rear
Post by: Joneyentee on 12 May 2007, 01:55:51
I was going to start a thread with this same name, so I might as well post here instead :)

I've noticed within the past week or so a knocking noise coming from the OSR when I throw the car into a left hand bend. It also creaked at me when I got out of the car Thurs evening. I've not heard it creak before and I'm not like I'm that heavy!

Any ideas as to cause and solution (preferably a cheap one!)?
Title: Re: dull knocking noise from rear
Post by: laughjimbo on 12 May 2007, 18:03:29
Thanks for that guys, i have checked all the bushes and everything and they are fine and the rear springs are fine too, i am going to check the door latch i a short while.
Let you know the results asap.

Jimbo
Title: Re: dull knocking noise from rear
Post by: laughjimbo on 12 May 2007, 23:39:24
Update, had my mate listen in the boot while i was driver earlier and he said the sound was coming from the new gas shochs and then as i was driving he said that there was loads of movement on the top of the shocks, too much. Checked the tighness of the nut on the top of rear shocks and they are done up all the way down to the bottom of the threads!!
Any ideas on why or what could be wrong, have they been fitted wrong or something???
HELP !!!
Title: Re: dull knocking noise from rear
Post by: Markjay on 13 May 2007, 00:24:39
1. Are you sure you have the correct Sachs shocks fro your vehicle?

2. Check that all washers etc are in place and in the correct order:

(http://img233.imageshack.us/img233/1889/shockgt3.jpg) (http://imageshack.us)

Title: Re: dull knocking noise from rear
Post by: laughjimbo on 13 May 2007, 15:33:04
thanks for that, i will check tomorrow if the rain stops.  Normally i do most things on the car myself but just had a new cam belt and water pump fitted so i thought that while they have got my car they may as well do the shocks, will do it myself in future.
thanks for the diagram, will get back to everyone once i have checked it out.
Title: Re: dull knocking noise from rear
Post by: curly on 14 May 2007, 23:10:53
hi mate,99%would suggest when the new shocks were put on the metal insert that sits in the middle of the bushes has not been fitted,as when you get the shocks that part never comes with them,you have to use the old ones which then seats the bushes together and centralises shock,so who ever changed them has left that part on old shock stuck possibly in one of the old bushes,thus why the nut has been tightened to end of thread nothing to lock it on to,lets hope they havent been thrown away??hope this resolves yourn noise from rear,(CAR),good luck,curly
Title: Re: dull knocking noise from rear
Post by: curly on 14 May 2007, 23:17:57
hi curly again it would be item number 14 in the picture that is the culprit??
Title: Re: dull knocking noise from rear
Post by: curly on 15 May 2007, 22:09:39
hi,have you managed to sort the problem out yet with shocks??curly
Title: Re: dull knocking noise from rear
Post by: wombatcurry on 15 May 2007, 22:32:04
Don't know about the knocking noise - but in the original post you mentioned a "creaking" - I replaced all 4 shocks earlier this year & for the next 2 to 3 weeks I had exactly this symptom - embarrassing as you get out of the car  :-[ - but it just went away. I suspect that it's the plastic "drainpipe" covers fitted to the shocks (Monroes in my case) rubbing & bedding in. Since then (3 months, 10k miles) - no problem.
Title: Re: dull knocking noise from rear
Post by: laughjimbo on 18 May 2007, 11:08:51
Latest Update, I have check the rear shocks and all the componenets are there. They are not sachs either, they are gabrielle gas shocks.
It does seem like the you are unable to tighten the top nut enough because maybe the sleve is too long or something. Same on both sides.
Any ideas anyone, could they have given me estate ones or are they completely different.

Title: Re: dull knocking noise from rear
Post by: jonathanh on 18 May 2007, 11:52:00
It seems a bit worring that the garage claimed to supply you with sachs but you end up with gabrielle.  

I'd double check the part number (should be on there somewhere) with a gabrielle catalogue.  If they are the right ones, then suspect the fittings as per the other posts
Title: Re: dull knocking noise from rear
Post by: Elite Pete on 18 May 2007, 13:08:44
I would take it back to the garage that fitted them. When you pay for a job to be done on your car you expect it to be done properly.
Title: Re: dull knocking noise from rear
Post by: Darth Loo-knee on 18 May 2007, 19:58:26
Quote
Hi Guys,
I have just replaced the rear shocks on my MV6 Saloon as they were getting really tired. I got a garage to do it and I got hold of some sachs gas ones, they are not the self levelling ones as my car has not got that feature but since they were fitted i have been getting a sort of dull knocking sound coming from the rear when i go over small bumps and it is really annoying. I have also got this creaking sound when i either go round corners or driving on and off my my driveway coming from just behind the drivers side rear passenger seat but the dull noise has only come about since the new shocks. The garage also told me that they checked all the rear bushes as i asked them and they were all ok. The car has only donw about 1000 miles since its last MOT which it passed with no problems.
Can anyone help please????
Thanks in advance!!

Jimbo

I had a dull knocking sound too when going over small bumps, i was in the boot listening where it was coming from while Mrs was driving like some Loo-knee ;D
I found the problem while t-cutting, the rear window had come away from the sealer so when you tapped the bottom edge of the window you could hear the dull bumping noise. Put some sealer and lovely and quiet now..
Maybe it would be worth a look :y
Title: Re: dull knocking noise from rear
Post by: laughjimbo on 20 May 2007, 11:15:53
Thanks for that, have checked the rear window and all seems well.  I have come to the conclusion that it may be the top rubber mounts as it ooks like the mechanic has not changed these regardsless of me requesting it. In future I am going to do the work myself if i can. Does anyone has any idea of how much these bushes are for the top of the rear shocks???
Title: Re: dull knocking noise from rear
Post by: laughjimbo on 28 May 2007, 15:38:36
Sorry guys i have not got back to anyone, just been on scout camp!!
Fitted new rear soch bushes from vauxhall, they come as a kit with new bolts and everything. They are alot better than my knackered old ones. Now i need to know if anyone knows how tight the top nut should be, i don't think they are supposed to be really tight. Can anyone help with this. I remember along time ago on the cavaliers the nut had to be so far down the thread but not tight!!
Title: Re: dull knocking noise from rear
Post by: Auto Addict on 28 May 2007, 16:03:04
20Nm