Mysterious front end rattle

[carey558899]

Hi, hoping someone can suggest what the mysterious front end rattle/clunking is that has evaded 2 mechanics and several attempted fixes! The symptoms on my 2002 Boxster S are:
- dull rattle that sounds like a "loose coupling" or a "bucket of large bolts"
- seems to be from the front and occurs when the front wheels hit a bump
- most noticeable at low speed (30-40kph or 18-24mph)
- most noticeable when driving over low but "sharp" bumps/cracks (e.g. bridge expansion joints or large cracks in the pavement)
- only occurs in warm temperatures (above 15C or 62F), and even then usually not til the car has been driven 15-20 minutes

Have replaced both front sway bar links and the right front lower control arm, but no noticeable improvement. Was led to believe by the first mechanic that I should now change the left front control arm, but the second mechanic disagreed after listening to the rattle and doing the "fender push test". Hearing the sound (while driving), he was in fact surprised that the first mechanic suggested it was due to the lower control arm. After putting the car up on the hoist and prodding the suspension components, he was unable to find anything abnormal.

Any suggestions or advice would be much appreciated as this is now driving me crazy! Thanks!

[Ghostrider 310]

02, original suspension components, I'd change the other control arm, in fact at that age I'd probably change them as a pair out of the gate. Your id says Ontario, I live in the freeze/thaw region too, think about the pounding the ball joints in that arm every spring on our rutted trails. Most noticeable over bumps is some suspension component, if the steering feels effected check the tie rod ends. One good thing is even if you chase your butt a little at that age replacing these items can only help preserve the performance and longevity of your vehicle.

[carey558899]

Thanks Ghostrider. The reason I haven't changed the other side yet is that the second mechanic said the rattling sound did not sound like a worn control arm bushing. What type of noise does this typically make. Thinking about it some more, I think I would best describe the rattling I hear as "a couple metal bars bouncing on plywood". It is triggered exactly when the front wheels hit the crack/bump. Each crack/bump causes a several rattles. Is this consistent with control arm wear?

thx

[Joe hockin]

Hey,
Did you ever solve it? I have those same symptoms...and have attempted the same fixes..no joy. How could such and obvious sound have such an unknowable source?

[ELoomis]

Did you check your spare in the frunk? It could be loose.

[Timco]

Originally Posted by ELoomis

Did you check your spare in the frunk? It could be loose.

Or the little bag of tools is loose?

Battery loose?

[nicecar]

i have been chasing this rattle for a long time no luck got excited with the tire mine wasnt loose 2 things left to change struts, sway bar links also thought that brake springs would do it no luck. because it doesnt occur when brakes applied buying jacks and stands and going after it my self this really sucks

[laphan]

I had the same issue last year. Car drove fine until it got hot, usually after 1hr drive. Took.it.to multiple shops and found nothing. After spent $300 total in inspection, I decided to get my hands dirty and started throwing parts instead... With my luck, the last piece that I replaced was the troublemaker. Ended up with all new suspension.
I started by replacing sway bar bushings, no change. next was drop links, no change. There was no play in control arms and track arms, so next was inner and outer tie rods. Multiple discussions in rennlist on 996 inner tie rods.making clunky noise when grease dry and car gets hot. no change..
so next was both control and track arms.. and same noise.
the last thing was strut and upper strut mount. that cured the problem. when I got the upper strut mounts from dealer, part number has been revised to 997 part. Front has 997 number and rear has been revised to 987 part.

I ended.up with all new suspension...

[nicecar]

replaced everything but the struts hard to diy/

[nicecar]

did you do the stuts yourself

[laphan]

Originally Posted by nicecar

did you do the stuts yourself

I did. it was really easy. car stayed on jackstand and rented spring compressor from o reilly. I removed the whole strut without even disconnecting brake lines.
I got the bilstein sport for $160 each from autozone. they often gives 20%off coupons.

[Steve Tinker]

Don't forget to replace the top bearings while the shocks are removed....

[linderpat]

had the exact same problem as described by the OP with my new to me 03. The ppi shop said it was suspension related. My local guy said everything there was fine. The sound was from a loose and out of adjustment front trunk latch mechanism. He adjusted it and the sound is gone. Cheap quick fix, probabaly an easy DIY. See if that works.

[Joe hockin]

I'm taking mine in today to have it put on a rack. Strut mount/strut is the most likely...how can the strut be diagnosed? Won't make the noise on the car.

[Joe hockin]

Hey,
What was your outcome...identical symptoms to mine

[dghii]

I messed with my 98 that had all sorts of rattling up front. Changing the struts cured the problem. I would guess that my issues could have been solved by replacing the strut bearing alone but I guess I'll never know.

[Joe hockin]

I changed the strut bearings...rattle persists...the shocks themselves sounded and felt good when out of the car. It now has new: control arms; tie rods and now strut bearings...gremlin?

[Timco]

The obvious has been covered. I am thinking loose fender well lining, mud in body parts, loose underbody panel or similar, loose parts in spare kit, license plate holder, trunk liner or something under carpet, loose bumper securing nuts / parts, or so on. What would have come loose over time?

Hamster wheel has new bearings? They can rattle. Got way better mileage when I changed his bearings.

[nicecar]

struts are left for you and me joe

[Joe hockin]

Can struts make a clacking rattle? The temperature sensitive aspect of a strut would make sense...when I had the struts out I cycled them without incident....I'm going mental!