Strange noise from rear?

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Gareth 161
Joined: Thu 08 Mar, 2012 23:41
Posts: 137

  Z3 roadster 3.0i
Location: Cornwall

Strange noise from rear?

Post by Gareth 161 »

Not me but the car!!!
My 1997 2.8 has recently started making a clicking/vibrating type of sound from the rear on left hand bends only and seems to be worse at higher speeds or bumpy roads.
Anyone any ideas what it might be as I am driving down through France soon and would prefer not to have any major mechanical problems whilst over there.
Thanks Gareth
2001 3.0 Z3, 2008 Subaru Forester Xten
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Heath
Joined: Tue 20 Dec, 2011 23:35
Posts: 112

  Z3 roadster 2.0
Location: Burton on Trent

Re: Strange noise from rear?

Post by Heath »

Check the handbrake shoes, mine was clicking & jingling on the back. The clicking was knackered handbrake shoes, the jingling was the rear pads as the spring on the back of the pad had been squashed in so the pad was rattling about


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Gazza
Joined: Tue 04 Oct, 2005 20:58
Posts: 9521

  M roadster S54
Location: Romford Essex

Re: Strange noise from rear?

Post by Gazza »

Check rear springs, they are known to break, you need to look carefully as it is usually the end section of the spring.

Check the shock adsorber top mount for wear or failure.

Anti Roll Bar (ARB) droplinks and mounts.
Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

Z3 S54 M roadster Image, BMW Z1, BMW M3 CSL, Z4M Coupe
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Gareth 161
Joined: Thu 08 Mar, 2012 23:41
Posts: 137

  Z3 roadster 3.0i
Location: Cornwall

Re: Strange noise from rear?

Post by Gareth 161 »

Updated symptoms
Still only happens when going fast over rough ground or left hand bends but did try pulling handbrake on slightly as mentionioned in another thread to see if that stopped it.
Strangely it makes the noise worse.Could it be the handbrake cable rubbing the driveshafts somewhere when the suspension is flexing and when the cable is under tension, it does not give way as much & hence more noise?
All very strange but frustrating.Wish I had a ramp to get underneath & see where the cables run.
Has anyone got any ideas?
Thanks
Gareth(will post pictures of car once it stops raining)
2001 3.0 Z3, 2008 Subaru Forester Xten
Gareth 161
Joined: Thu 08 Mar, 2012 23:41
Posts: 137

  Z3 roadster 3.0i
Location: Cornwall

Re: Strange noise from rear?

Post by Gareth 161 »

Strange noise partly resolved.

Whilst lying under the car last week (as one does) trying to feel for an exhaust leak the MOT chap mentioned(could not find one & he passed it anyway), I noticed that the LH handbrake cable above the heatshield and barely visible near the prop had a flat spot on it.
Therefore this has been the strange noise I have been getting and now explains why when the noise was there, applying the handbrake would make it worse as presumably it would tension the cable down more onto the prop.

I can breath a sigh of relief that at least I now know what it is and it is nothing teribly expensive(had visions of rear drive/CV joints failing or diff packing up.
Question to those in the know is what is causing it to happen as I suspect it should not rub?I have checked where it is clipped on near the wheels and that seems OK and handbrake works fairly well athough possibly needs slight tightening up as needs a bit of travel to engage(although again has just passed MOT).
Anyone got any bright ideas?
Incidentally my erratic idling/over revving seems OK again now the weather has cooled down a bit?
Thanks in advance
Gareth
2001 3.0 Z3, 2008 Subaru Forester Xten
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Southernboy
Joined: Thu 07 Oct, 2010 12:39
Posts: 6436

  Z3 roadster 3.0i
Location: Johannesburg

Re: Strange noise from rear?

Post by Southernboy »

If your H/Brake isn't working as it should...remove the handbrake gaitor in the car..you will see the two adjustment cables there with their nuts and locking nuts. They're a B** to adjust, but with some effort it can be done. You will need to re-adjust both cables to balance the braking action equally on both wheels. You will possibly find that the one side (probably the side with the damaged cable covering under the car) is very loose or overly tight. The best way to adjust the brakes is to do the entire routine. ie:- ..1. release the tension on the cables at the handbrake lift handle in the car completely...then 2.remove both rear wheels & raise the car onto stands....use a decent flat blade screwdriver and release the brake shoe adjustment through the hole in the rear drums by rotating the serated adjuster...another B** type job...then with the handbrake lever in the released position, adjust those serated screws through the drum until the brake shoes "grab" onto the inside of the drums..you will know when they do by trying to rotate the hub...adjust the serrated screw one click at a time until the hub cannot be turned, then adjust the serrated screw in the opposite direction 3 - 5 clicks so the hub turns freely without any "scraping" against the brake shoes inside the drums...do both wheels until you are satisfied that you have them pretty much equally adjusted. 3. Go into the car and lift the lever 3 - 4 clicks and adjust the cables evenly until they both lock the rear wheels...without an assistant this requires getting in and out the car every turn of the adjustment nuts and testing the relative wheel for brake shoe friction. Once you are satisfied you have them "about right" replace the rear wheels and try to park the car on a slope...allow the car to roll backwards and apply the handbrake...it should brake evenly...if it doesn't, you will notice that the one side of the car will "lift" at the rear more than the other...the side that "lifts" is the side which is applying the brake...adjust the opposite side to achieve more brake friction until the car brakes evenly on both wheels.
The wear on the cable under the car is possibly due to the cable being under tension and rubbing against the rear axle as it moves up and down whilst driving...there should be fairly large white plastic clips on the underside to hold the brake cables securely out the way... :wink:
"Normal is overrated"
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Gareth 161
Joined: Thu 08 Mar, 2012 23:41
Posts: 137

  Z3 roadster 3.0i
Location: Cornwall

Re: Strange noise from rear?

Post by Gareth 161 »

Thanks For that extensive reply-I will put aside some time to do as suggested although no immediate rush as handbrake is working reasonably well & MOT passed.
My main worry was working out what the noise was!!
Have another nice job to do first-the plastic seat bushes which have been "resting" in the shed for several months!!
Time to look at that video on seat bush replacement again.
Cheers
Gareth
2001 3.0 Z3, 2008 Subaru Forester Xten
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