Re: I had a bunch of those in the 197K miles of ownership 2000 Boxster S

Hi folks - spent several hrs @ an independant mechanic shop the other day. I had noises from the front and rear of the car. The FRONT I covered in another post. But now I wanted to ask a question about the noise from the REAR.

When driving/coasting at any imperfect pavement (like an open walmart parking lot) - at speeds as lows as a few MPH..... it is really easy to hear all kinds of CLUNKING noises from somewhere in the rear. My mechanic road w/ me and also could hear it easily. Then when the car was put up on lifts and they went around banging everything w/ a rubber mallet and pushing on the car/etc, they couldn't hear the same noise. Visually looking from underneath they didn't seem to find any parts that looked worn that might have caused the noise.

I'm at a lost and frustrated and want to get this fixed! Anyone resolved a similar problem and know what needs to be replaced?

consider brake pads loose in their nest in the calipers and these can move about and make noise at slow speeds when going over speed bumps or entering or leaving a driveway with its severe dip as long as one isn't applying the brakes at the same time.

Check the nuts that hold the stiffener panel to the rails under the rear of the car. My Boxster lost a few of these some time ago. Apparently they just came loose and fell off.

can find some noises. But not loose ball joints or worn bushings that allow the suspension to move under stress.

Those need to be found via prying - with hands, a pry bar, etc.

You could have an exhaust that taps something when you go over bumps. Those would only be heard under large excursions (not taps, or even whacks).

Marc mentioned some other ideas. I find the brake pads, unless the pistons are frozen or the pads mis-installed, unlikely.

I too had a diagonal brace nut loosen - and fall off. At Watkins Glen (shiver). The problem with them is if the diagonal brace is not completely seated, and you tighten the nut down, and THEN the brace seats itself, the nut is now completely loose. They must seat square and easily before the nuts are torqued down. and I torque them a bit at a time, end toward center. Sorta like head bolts.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

conditions hear the pads knocking about. Not real loud, but moving slow on rough road surface or going over a speed bump at an angle, or during a sharp slow turn with the windows down I can hear what I believe are the pads.
There's nothing else loose. The tech checks for this every time I have the car in, he gives the car an inspection looking for things amiss.

I know the brake job parts list no longer requires the inserts that fit into the piston and have a pad that sticks to pad backing plate, so the pads are a bit freer to move about in the pad nest in the caliper.

I will put big money that it is a control arm..... I replaced a bunch of these over the life of the car. I could only hear the clunking on rather smooth, undulating roads at low speeds.... parking lots etc.

As you note, identifying the offending arm is pretty difficult. I put on miles faster than any one else my local dealer had seen so they had no experience base to judge the offending part (the first time it happened). The way he diagnosed the clunker was using chassis ears. However, we now have an experience base and the offending arm is usually the lateral arm.... the one that goes front to back. Banging with a mallet or wedging a tire iron in there will only reveal a really failed arm.

I will bet it is 986 331 043 04 ( don't know if left and right are the same number) about $380 for the part.

The only other clunking/rattling etc I ever really had other than a control arm, was the heat shields buzzing and rattling. But those are higher-pitched noises.

Peace
Bruce in Philly



Edited 2 time(s). Last edit at 05/04/2014 10:42AM by Bruce In Philly (2000 S Boxster, now '09 C2S). (view changes)

Thanks for the information. I will keep it in mind. I tried to check it w/ the car on the ground and at least there, it felt really solid. And can't see anything loose in the brake pads that could make noise like I'm hearing. Chassis ears I can ask about the next time I go back to the shop but no idea if they have them (I am just learning about that and from googling it - looks like something electronic - the shop was using something akin to a doctor's stethoscope to try and listen for the sound when I was watching them).

How about the rear struts? If when pushing down hard on the fender (or jumping on the door sill w/ the door open) I can't hear/duplicate the same noise, the struts should be fine right?

Grant

gee-lenahan-at-gee-mail-dot-com

Don Rosen had it up on the rack...... actually, they went so far as replacing the sway bar links first... They took it for the test drive, and it still clunked. That is when Bill pulled out the chassis ears and made a more definitive diagnosis.

Peace
Bruce in Philly

Wishbone has the ball joint.

Track arm is this thing, looks like a tuning fork:

[www.pelicanparts.com]

Grant

gee-lenahan-at-gee-mail-dot-com

[www.elephantracing.com]

They keep the wheel from moving fore-and-aft. They connect via a center metal bushing in a rubber bushing. You need to move the wheel foreward or backward, a lot, under great pressure, to get them to make noise. The very movement should be a give away.

mechanics, alas, are often in a hurry or follow rote procedure.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

No clunking or measurable looseness, but i wanted a really solid platform for the track and would likely have killed any marginal part in a few days.

So i just replaced anything you didn't get to yet.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com



Edited 1 time(s). Last edit at 05/06/2014 08:20AM by grant. (view changes)

Chassis ears??

Chassis ear?

the mechanic listens on a receiver with headphones while the car is driven.