dmw

I have the same issue. I only notice it in the summer/hot months. I think I traced it to the tie rod ends. One side is rock solid. The other side has some play - BUT only if it’s hot outside and the tires need to be under load (lifted from the tires, not the jack points). I’m taking it to my mechanic next week. We’ll see if that fixes the problem. Really annoying.

Cogito_Ergo_Zoom

Is your car a C2 or C4?

dmw

Mine is a 2002 Carrera 4S. My clunk is most noticeable on hot days driving slow on slightly bumpy pavement.

Cogito_Ergo_Zoom

Have you inspected the drive axle?

dmw

I think the shop did. I’ve been under there and didn’t see anything obvious. But the noise doesn’t change regardless if the car is in gear or coasting in neutral. What should I look for?

Cogito_Ergo_Zoom

It's worth checking to eliminate. The heat aspect makes me think the grease could be insufficient and/or thinning out at higher temps and you have excessive wear and play in the CV joints.

Are there any tears in the boots? If you don't see any tears, then check the CV joint itself. Get the car up safely and slide the axle in and out to see if there's any strange friction, roughness and/or clicking. If you do, it's worn and needs to be replaced. If nothing seems out of sorts there, grab the axle near the inner boot and try to move it in around in an oblong fashion like you were stirring a mixing bowl. If there's play, it's bad. Do the same thing with the outer joint.

jumpy chunky

Tuning forks fixed the rattle in the front end of my 996 C2.

rufrob

Thanks for replies and info. My car is a 02-996TT.
Next I'll try the tuning fork. The catalog calls it the control arm. Strangely, it's intermittent. I drove the it yesterday, the first 10mins were noisy as hell. Then nothing. Smooth and quiet.
I also noticed the front end seems noticeably tighter after swapping the upper strut mount with the 997 unit.
Btw, has anyone tried the upgraded poly urethane bushing?
https://www.europeanpartssolution.com/cart
It's the same price as an OEM part!
I also did the cv boot on the right side.
All I removed was the control arm/tuning fork at the coffin arm, coffin arm from the body and that was enough to swing the hub assembly forward enough to clear the driveshaft. Btw the 928 CV fits.

Cogito_Ergo_Zoom

Rufrob, do the same CV joint test to eliminate that. If the first 10 mins of your drive yesterday were typical around town stuff--accel/decel, sharper steering angles, bumps--that could be a clue. Bad CV joints are usually noisest in those situations and then quiet down a bit at highway speeds when you're driving in a straight line. Why did you replace the inner boot in the first place?

If it's not that, it sounds like you've checked/replaced everything but the two LCA connections (outer ball joint & inner bearing) and the two tension/"tuning fork" connecting points. After that the only other likely culprit would be the swaybar bushes.

rufrob

The cv boot was done on the right side while
the noise was coming from the left.
No highway driving only city.
It feels so much better after the 997 strut mount was installed. I actually enjoyed driving the car. Ordered the thrust/control arm.
Next issue is a slight gas odor only with AC on at slow speeds.

Looneybin

Tuning fork test
if the clunk/rattle goes away when you are braking, it’s the tuning forks
if the noise persists under braking, it’s the upper strut mount or tie rod ends

PCAR996C2

I had both upper strut mounts replaced due to the creaking noise when turning slow. After about 6 months a small front end rattle on one side turned into a rally loud rattle. Turns out one of the nuts on top of the suspension had come loose!

rufrob

Replaced diagonal control arm today. Same noise. The LCA bushing looked fine. I'm beginning to suspect the outer cv joint. I heard a slight popping cv noise for the first time. I have been hearing tensing noise from the rear axles too. I guess a cv grease repack won't hurt.

dmw

We finally figured out my issue. It was the steering rack.

808Bill

Rebuild or replace?