Rattling Noise from Rear of Boxster

[dcboxster]

Hello Chaps!,

I have a late 97 boxster with around 55k on the clock and have a really annoying rattling noise from the rear of the car. This only ocurs when I drive over very bumpy road surfaces such as the slip resistant finish they are applying to areas of risk here in the UK and is especially bad on a concrete road. The noise stops instantly as soon as I open the throttle or ride the brakes. It also seems to be worse once the engine has reached normal operating temperature. I have been in touch with many other boxster owners who say that they have exactly the same problem, but have not been able to work out what the problem is. Furthermore, this problem has completely perplexed 2 official porsche centres in the UK. Something else worth mentioning is that the noise comes sometimes from the left rear side of the car, sometimes from the right rear side of the car and on surfaces such as concrete roads both sides at the rear. I don't think that the problem is drivetrain related as there is ansolutely no driveline shunt, therefore, I am convinced that it is something to do with the suspension make up. Anyway, any comments/suggestions would be appreciated.

[Loren]

Fairly common is loose sway bar mounts - so that would be a good place to start.

[dcboxster]

Fairly common is loose sway bar mounts - so that would be a good place to start.

<{POST_SNAPBACK}>

thanks i'll try that next

[Highlander]

While you are in there, check the torque on the drop links. If it not swaybar related, check the nut holding the strut together. If this backs off even a little, you'll get an infrequent and annoying "clunk"

Good Luck,

Graeme

[pbox986]

hi dc boxster,

i have the same problem with the rattling noise on my 97 box at same location and condition.. .. please let me know if u were able to resolve the problem and if u did can u kindly please inform me on how it was resolved.. i will let u know as well if i run into a solution for it.. in the mean time im still searching for an answer...

best regards,

frank

[dcboxster]

Hello Frank,

A mate of mine diagnosed the problem as the ball joints in the rear lower suspension arms that link to the chassis. The ball joints become worn and are itegral to the whole arm. I am having both the left and right arms replaced in the next fortnight and hope this will cure it. The arms are about £180 each inc. VAT and take 1-2 hours to fit.

If your rattle dissapears when opening the throttle and is affected by temperature, then I think that you could have the same problem.

I'll let you know if this cures the problem on my car, but please see the links below to threads on the Boxa.net forum which you should find self explanatory. This goes into much more detail about the problem with other owners that are also experiencing this/or a similar problem (I'm dctvr in that particular forum).

If the link doesn't let you through, then sign up, as it is free and I beleive will help you no end.

http://www.boxa.net/forum/index.php?showtopic=14089

http://www.boxa.net/forum/index.php?showtopic=15100

Regards,

Dave

[pbox986]

hi dave,

yeah.. the rattling noise seem to go away as i open the throttle or when i speed up. the noise is most apparent when i accelerate in 1st gear coming from a complete stop and sometimes in 2nd gear at a low rpm. please let me know how your current fix turned out.

thanks/regards

frank

[GreigM]

I have a similar problem/noise at the front of my GT3, and have diagnosed it as the anti-roll bar mountings (I can see the marks on the bar where it is knocking against the chassis). I am having the car looked at on wednesday by a local motorsport mechanic, so will report back to confirm.

Basically the symptoms are a knock/clunk noise when at relatively low speed over bumpy roads. Seems to disappear at higher speeds.

[GreigM]

As suspected, the anti-roll bar had come loose....just the vibration over time had made it happen. 2 hours labour to fix, no parts required.

[Loren]

2 hours labor for a 15 minute job? Oh my...

At least it is fixed now :cheers:

[GreigM]

Well, it was 2 hours labour charge, but to be fair their hourly charge is £25 per hour compared to £100 at th Porsche Dealer, so I presume they have a minuimum charge to make it worth their while.

[dcboxster]

Hi Frank,

The rear lower suspension arms (and integral balljoints) have now been replaced and all is quiet. My mechanic mate (Audi Master Technician) recreated the problem by putting the car up in the air and jacking the offside rear wheel up into the arch immitating the car under normal load on the road. I then proceeded to strike the rear offside rear whilst he listened for the rattle underneath. Although there was very little play in the ball joints to these arms you could hear and feel the rattle if you held the balljoint whilst the wheel was being struck.

My mechanic mate reckons that this is also a common problem on Audi TT's, so Porsche are not alone with their poor development. However, I suppose you half expect this with specialist cars (I had a TVR Griffith 500, which cost me on average about £800-£1000 a month in replacement parts!).

Anyway, if you have this checked out by your mechanic the part number is as follows:

986.331.043.07

The part is the same both sides and it is worth doing both at the same time even if one is more worn than the other. It took my mechanic about 45mins to fit both parts.

Let me know how you get on.

Dave (dcboxster)

[ricorico1]

k

Edited October 1, 2008 by ricorico1

[ricorico1]

hi just thought i'd mention my 2000 2.7 drove horrible creaking front suspension and loud knock on passenger side rear all these on bumpy roads at 15 - 30 mph it really felt like a bag of s--- like riding on rusty bed springs and loose. Thought what a lemon i'd bought. Went to indy and replaced front coffin arms I am in UK(lower track control arms) and rear forked control arms (lower control arms) no 8 on the pic and car felt good and tighter. Dont know how a new one drives but the bumps now feel and sound like my 3 year old peugeot so acceptable as i cant envisage dampenend remember we're talking about bumpy roads

Edited October 1, 2008 by ricorico1

[kbradley]

I have been experiencing a seriously loud rattling noise (enough for people to stare!) when starting up and when sitting in traffic in my 1998 2.5 986 . The sound also happens over some road surfaces like you experienced. The sound was literally like a metal tin of washers being shaken. My problem sounded serious but it was just the heat shields below the cat sensors rattling due to corrosion. These are the heat first heatshields coming down from the manifold. My solution was just to apply a small quantity of exhaust cement in between the shield and exhaust. So far it has completely fixed the problem.

If it fails in the future I may remove the heat shields and use exhaust wrap.

Regards,

K

Edited December 14, 2008 by kbradley