Rear suspension noise

[Rev Den]

I have a noise coming from my rear suspension that is getting worse. It sounds like a clunk or knocking when I go over a series of bumps or single bump. If you are driving it sounds like it is coming from the rear passenger side. If you are riding in the passenger seat it sounds like it is coming from the driver side rear. Acceleration does not cause the sound, only bumps in the road. The sound is the same with the top up or down. My local mechanic and I ckecked the rear struts and sway bars and everything seems to be tight. Does anybody have a clue what it might be?

2002 Boxster

[der Geist]

One possible thing is that it could be your shock. The sound you are describing could expain it however it usually always sound like it is coming from the same side and does not move around. It is highly unlikely that both shocks went at the same time. Did you look to see if any of the fluid has leaked out of the shock assembly? It will usually be apparent on the inside fender or right on the shock itself. When a shock loses it's fluid it can make a sound exactly like what you saying but whatever it is it sounds like it is related directly to the suspension or something attached to it.

[Rev Den]

I checked again and there is no evidence of any shock leakage. After some more driving I think the sound is only coming from the right rear side. The shock seems to still have good compression when you press down on the rear end. Any other possibilities?

[faheemf1]

It is possibly your rear track arms. Have you had them checked?

[rgriffin]

My car makes the same noise. I had it checked out and mechanic cannot find anything wrong. I heard a similar noise from my 2000 Z3 when it was brand new.
I thought maybe it was just characteristic of convertibles.
To me, it sounds like it is coming from an area between engine and rear seats, possibly low to ground, but I cannot distinguish which side if any.

[JackG]

Count me in as well, it's on the driver's side, behind my left shoulder, but it's hard to tell how far up/down. I had my alignment guy look at it, and he couldn't find anything.

It will pop when it's being jacked up off the ground, and will pop either when it's let back down, or when you sit in it after it's back off the jack. When driving, it will occasionally pop when cornering hard right (and loading up the suspension on that side), and will especially do it if there's a bump in the corner that loads and unloads the suspension.

My noise sounds like someone lightly tapped a solid part of the frame/suspension with a ball pein hammer. Like maybe a bolt is loose, and whatever it's holding can slide around under it's head? But the weight of the car normally keeps it from sliding.

A bad strut (shock) is a good idea. I've looked over the bottom, I'll have to take a closer look at the top of the strut and it's mounting area. I guess it could be internal as well. It's not leaking on mine.

[CJ_Boxster]

When my rear end started to make that noise it was the rear-track arm control arms. There is really no way of checking them cause the play that the bearing cartridge develops is as thin as a hair but can cause ALOT of clunking and chattering from the rear end when going over bumps.

DIY - Replace Rear Upper Control Arms (Track Arms)

Che @ delubozparts Rear Track Arms GB $249.99 Shipped

[der Geist]

A bad shock will almost always show some sign of leakage from the cylinder. When driving with the top down it will be very clear that the sound is coming from the top of the shock tower. Maybe you could put a lubricant on the moving parts of the track arms one at a time to isolate the problem. When the noise stops you have found the bad part. Not foolproof but it may be your only choice of diagnosing this if the mechanics can't be certain.

[CJ_Boxster]

Too hard to put lube on the track arm that I'm talking about cause its got a rubber flexible boot on both sides of the cartridge. Chances are that it is his track arm control arm that I'm speaking of cause his symptoms are 100% identical to the symptoms i had experienced when my track arms failed.

[der Geist]

If the symptoms are 100% then I guess there is not much point to doing anything other than switching them out. Should be a nice project for the weekend.

[CJ_Boxster]

Yeah, my front track arms should be arriving today so that will take care of the noise i get from the front as well.

[PhxRealtor]

I have the same noise. Only hear it when I go over a series of small bumps in the road. It's loud, sounds like something loose behind me clunking.

[Padawan]

I notice a sort of muffled rattle or knocking over bumps when the car is cold (as in, just started it up and driving a few miles), but it doesn't sound metallic. It almost sounds to me like it could be coming from the engine cover, but I haven't tried to locate exactly what it is. It seems like an impossible task.

[CJ_Boxster]

Originally Posted by PhxRealtor

I have the same noise. Only hear it when I go over a series of small bumps in the road. It's loud, sounds like something loose behind me clunking.

Yup thats about when you hear it most, you'll also notice that as your speeds increase the noise fades abit, anything about 15 to 25 mph is when its loudest.

[CJ_Boxster]

Originally Posted by Padawan

I notice a sort of muffled rattle or knocking over bumps when the car is cold (as in, just started it up and driving a few miles), but it doesn't sound metallic. It almost sounds to me like it could be coming from the engine cover, but I haven't tried to locate exactly what it is. It seems like an impossible task.

Hmmm, not typical of a rear track arm failure, Usually the track arm will make more sound as the day and bearing cartridge warm up and is quieter when cold.... my thought is that nylon bushing within the cartridge softens up when temps around it increases... remember the exhaust manifolds are very close to the bearing cartridge.

[Rev Den]

I finally replaced my right rear control arm and the noise is gone! Thanks for the advice.