997.1 front suspension rattle help needed

[brendel]

Hi Everyone,

My C4S 2006 80KMiles, was making bad noises from the front suspension, squeaking + rattling

My car being under guaranty, I went to my porsche center to ask to fix it ( it all happened over a year time)

First visit changed the droplinks, + Sway bar bushing+ tower bearings

No effect

SEcond visit, they changed the suspension + springs + control arm ( coffin one), squeaking is gone and rattling only partially, I still have an annoying rattling at low speed

Third visit, they changed the suspension again (and screw up my wheel geometry) but the rattling is still there

I noticed that the rattling is more pronounced when I go over a bad road and turn, going straight seems fine, I can also feel it in the steering wheel which makes me even more mad about it

To summarize, the only parts that are not new are: Tie rods ( but I have no play in the steering), diagonal control arm

Which of the 2 is more like to be the trouble maker?

I have spent evenings on the forums but cannot find a good technical answer on this

Thanks

[brendel]

I was asking for help :huh:

[Loren]

Inspect the control arm bushings and the steering rack mounting bolts for tightness.

Many times you can see issues with the control arm bushings when they go bad.

[997_rich]

can you give some more info on the rattling? you feel it only in the wheel? do you feel it in the shake of the car? what does it sound like? like a washer dancing around on a loose bolt, like a bell ringing, like clunky rattle, like a quarter rattling in a coffee can, like a hockey puck bouncing around in a bucket?

you're sure you can't feel a click or anything in the steering? I had a bad steering universal.

it could be a loose ABS or brake line on the wheel carrier.

[brendel]

What is a steering universal?

What do you mean with loose ABS? the whole control box ?

Driving with music I cannot feel anything strange in the steering, so it must be somewhere else

The noise is more like the hockey puck in a bucket, "clonk"

I would describe it as reactive rather than direct, which makes me think there is something loose out there, it really occurs if the road is bad in a turn or while braking ( on bad road)

I have heard of the airco line in the right front wheel arch being loose from its clamp, I have checked that previously but since they messed around with my suspension at the garage, I would need to check this again

All in all this seldom happens and I can only hear it at low speed, maybe I should avoid bad roads and low speed...

I extended my guarantee last week and the porsche guys are fed up with this car, they do recognize there is a noise, but since they changed a lot of parts they don't know what to look for anymore

[997_rich]

Ok, first I would completely clean the frunk to make sure there's nothing in there. I'd also take all of the frunk plastic trim off and put a hand on every visible component (like the battery or wiper motors) and shake the **** out of it. I'd do the same thing on the bottom of the car.

If it's none of this my best assessment based on "in turns or when braking" and "hockey puck in a bucket" and "reactive" is that it's a control arm bushing. go to a parking lot and do a few braking situations from 25mph, do it straight, then in a right and left turn, try it again and again and add braking force each time. If you can get to a point where you consistently feel braaaaaaaake-clunk it's almost def a control arm bushing. The force builds up and then all the sudden the bushing pops.

It is just one hockey puck clunk, right? or at least a clunk-return (bad-dunk). If it's a true repeated clunk the control arm diagnosis might be off.

[brendel]

Thanks Rich,

I looked yesterday at the control arm, they look good, I tried to quick the wheel while while turning completely and there is a "clonk" indeed, since it is the only part that I am not sure if it was changed or not... I also found a big connector in the right wheel arch hanging loose close to a metal piece ( the one holding the light), I will test the car today...

The trailing arm part number on the catalogue is 997 341 043 00 the part on my car is 997 34 143 00, I was wondering if I had the older number or a new part number in which case porsche would have replaced one by the other, does someone knows that? it seems to be the same part for CAymans boxters and 997s, I have seen the 997 341 043 00 mounted on 2010 cayman ( ebay ) so I might have an older number

Thanks

[brendel]

The trailing arm part number on the catalogue is 997 341 043 00 the part on my car is 997 34 143 00

Would anyone know if I can use the 043 vs the 143 on my C4S from 2006?

How do you find out that a trailing arm is to be changed

Thanks

[Loren]

997 34 143 00 is not a good part number.

According to Porsche's part list (PET) the only part number for your car is 997-341-043-00.

[brendel]

Thanks Loren

I cannot find the "...143..." in the porsche parts catalogue either, I suspect it to be first part number in 2006 then replaced by the ...043... later on

I will make a replacement of the track arms on both sides and photo document it on the site

Thanks

[997_rich]

Trailing arms and control arm bushings are difficult if not impossible to check without pulling the bolt and looking at it. They only pop out of center when under force. You can't see the bushing inside the mounting ears.

[brendel]

I ordered 2 trailing arms for the front, I guess wheel realignment is needed? can the bolts be used a second time?

I also had some heavy noise when hitting a pot hole from the rear, see what I found, the bushings seem to be broken, there are all like that, even the bushing of the shock absorber, I guess there must be one elements being more faulty than the others, by where would you start?

It seems that control arms last about 80K miles on a 911, though I don't see much documentation on that on the net, there is always one person changing a part after hearing a clunking noise ( like me), there must be a logic order on what is getting worn first, anyone would have that ?

Thanks again for all your advice

[brendel]

Just a little update

The front of the car is now all new

Strut, strut bearing, strut tower..., Sway bar bushings, end links, Coffin arm, control arm, tie rod inner and ends

And the car still rattles when I put in PASM sport, I car ear it at low speed over potholes, not speed bumps though

I really do feel there is something loose out there, I did drive with an empty trunk...

any idea?

[Loren]

Just a little update

The front of the car is now all new

Strut, strut bearing, strut tower..., Sway bar bushings, end links, Coffin arm, control arm, tie rod inner and ends

And the car still rattles when I put in PASM sport, I car ear it at low speed over potholes, not speed bumps though

I really do feel there is something loose out there, I did drive with an empty trunk...

any idea?

Did you check TSB 3/05 4078 Rattling Noises From The Area Of The Front And Rear Axle -- dated Jul 5, 2005?

[brendel]

Thanks Loren,

Yes I have seen both TSB the March and the July one, my whole struts and coils were replaced twice within one year at Porsche, this was performed under guarantee, I assume this is the first thing they look at and the end liks have been changed one year ago

The car is still under guarantee but my dealer just don't know where to look and they have been in contact with the factory tech crew...

I noticed that my front right CVjoint has longitudinal play, ( quite a lot, 1/4 inch ) the left one can hardly be felt, but I was told that only axial play maters with CVjoints

I was thinking also, could that come from the steering rack or steering column, or front diff? they are somehow screwed to the cross member ?

To describe the phenomenon again, I get a rattle at low speed only in Sport PASM, I guess I cannot hear it anymore when driving faster, It does not happen on speed bumps but only on potholes, It is somehow amplified if I hit a pothole while turning

And again, all the potential culprit have been replaced by new parts ( both control arms , sway bushing, end links, struts, coils, strut bearing and top bushing, inner and outer tie rods)

Thanks

[Loren]

Since the car is lower (and stiffer) in Sport PASM - I wonder if that puts more stress on the steering box.

I would ask them to double check the tightness of the steering box mounts.

[brendel]

Thanks I will and keep you updated