REAR END KNOCK

[porky700]

can anyone offer any advice, my boxster 986 has a dull knock from the near side rear, ive changed both rear shocks,drop links and fitted poly bushes the rear anti roll bar, its sounds as if its under soft top cover, it s still there top up/down, its driving me mad

 

[Glyn]

This will be the rear forked control arm (very common fault) - the sound is often like having marbels banging together, £90 from Hartech

 

[gcorner]

At the risk of seeming stupidly "low tech", do you have an empty rear luggage area? Just checking because I had a dull regular knocking round the back end of my 987 that I eventually traced to an umbrella handle in the corner of the boot, fortunately I identified the offending item before reporting the issue to a mechanic. The sound occasionally returns, depending on what I am carrying. The boot liner seems to act a bit like a drum and appears to bounce some items up and down quite nicely.

 

[gcorner]

Forget I said that - its been going on too long. I'll not delete my post in case a new owner finds an occasional dull knock and looks at this. Good luck with the cure. Previous comment looks better than mine.

 

[porky700]

thanks for all the advice,even the boot theory,is it possible to poly bush the control arm, or simpler to replace with new

 

[Andy Fagan]

]

 

[Glyn]

Hartech are reconditioned parts, dont know if you can get the bush alone and DIY but for £90 you get what is a new unit and just two bolts to fit so it saves downtime

 

[GOOFY]

Hi Porky700

Have you checked the front engine mount ? Front engine mounts seem particularly prone to degradation after time. If you also have a large play in driveline (i.e. lurch when deaccelerating/ accelerating) then this (fron mount) may be the cause. Mine went quite early on.

But I also have exactly a similar noise rearing itself now - very hard knocking over bumps when car is cold for some strange reason. It felt as if the rollbar was knocking against a roof strut in the car - it was so loud.

I am very interested in how you get on so please let us know if this cures your problem.

Regards

 

[cjdavidson]

Rear control arms are a very common problem,
sounds like pool balls being racked,when going slowly over rough surfaces.
Pretty easy & cheapish to sort.

 

[porky700]

Thanks for the advice guys, watch this space over the next few weeks,and hopefully a conclusion

 

[porky700]

HI GUYS, finally after listening to my local garage for the last time , I took the car to zentrum at calverton Nottingham.Where i was met with a welcome coffee and a chat, the car was taken on a short test drive and then taken into the workshop, after a full inspection i was shown what the problem was... both coffin plates and control fork arms. i have purchased all the parts from europart which are trw genuine porsche for a mere £249 inc vat. The car is booked into zentrum for sat morn.

 

[porky700]

What a relief to drive a car without a knock, squeak or bang,YES Zentrum of nottingham found the problem straight away, After changing-rear shocks-drop links-anti roll bar bushes, And still not finding a solution i finally saw sense and took the car to professional porsche mechanics,and i even supplied the parts myself,They changed the coffin arms and fork control arms, Job done
Zentrum gave me a first class service at a price that was very reasonable, and would certainly use them again

 

[GOOFY]

Hi porky700

Thank you for feedback on the issue and glad it was not too expensive either !
I already have the front arms ready to fit, as these seem to wear out first according to forums, now may think about also changing the rear !

 

[porky700]

Dont forget to have the car re-alighned as even a 1 degree change will scrub the tyres