991 metallic 'clang' noise over bumps

[fistenburger]

My 991.2 S has developed a noise when driving over bumps in the road. It's only audible from the outside of the car or whilst driving with the window open.
The noise seems to be from the rear of the vehicle, and sounds very metallic - like two spanners banging together.

I had the car over at Center Gravity on Monday and they couldn't find anything wrong or broken (they transformed the handling of the car BTW).
I looked on Rennlist where people have discussed loose engine covers, missing fan grommets etc. I checked these last night and everything seems ok.

Any ideas what it could be?

[av185]

I've had a couple of 911s (991.1 and 991.2) with simlar noises which proved to be faulty hinge mechanisms on the rear engine lid which were replaced under warranty.

[LeoSayer]

Give the exhaust a wiggle and see if you can recreate the noise. Maybe a loose heat shield.

[elisered]

Had something similar - turned out to be a loose (completely undone) brake calliper bolt. Probably undone earlier in the cars life and retightened rather than being replaced.

[That White GT3]

Bit of an old thread but i have this exact noise currently, did you manage to find out what it was in the end?

[willisit]

I didn't see this originally but mine was a broken rear spring.

[That White GT3]

willisit said:

I didn't see this originally but mine was a broken rear spring.

Just had a feel around and its sharp round the back with the coating worn off so i assume this will be it.

Thanks.

[MinchCS]

fistenburger said:

My 991.2 S has developed a noise when driving over bumps in the road. It's only audible from the outside of the car or whilst driving with the window open.
The noise seems to be from the rear of the vehicle, and sounds very metallic - like two spanners banging together.

I had the car over at Center Gravity on Monday and they couldn't find anything wrong or broken (they transformed the handling of the car BTW).
I looked on Rennlist where people have discussed loose engine covers, missing fan grommets etc. I checked these last night and everything seems ok.

Any ideas what it could be?

Can't help, but at least you know it's nothing to do with the suspension - CoG are so particular they will have found a problem there.

[fistenburger]

I had the same symptoms on my previous 991.2. OPC couldn't find anything wrong, but RPMtechnik found a broken rear spring.
Car felt fine to drive, the only symptom was the noise.
I suspect my GT3 now has the same thing.

[That White GT3]

fistenburger said:

I had the same symptoms on my previous 991.2. OPC couldn't find anything wrong, but RPMtechnik found a broken rear spring.
Car felt fine to drive, the only symptom was the noise.
I suspect my GT3 now has the same thing.

I have a GTS now but a GT3 prior to it and the front spring did the same at 13k miles!

[996Targa]

I had a similar issue which i mentioned at a service time but the OPC couldn't find anything wrong. I persisted and they sent out their "Gold" technician with me and I drove the car over a speed bump. Straight away he said "leave it to me". There was a stone trapped in the rear suspension.

[JamesW]

Same here - small stone trapped in the rear suspension. It wedges itself further and further down until you get a bang/clunk and it returns to the begining to repeat the process. Really annoying and took two trips to Porsche to fix it