Hey guys, just had a set of GMG WC springs installed on to my 997.1 TT.

Stance looks great, and the car handles better

However, over certain bumps, I am getting a knocking noise from both the front and rear. This noise has never been here before until immediately after installing the GMG springs. Everything has been rechecked, and was/is installed properly.

Installer is Porsche trained technician with over 20 years at an authorised dealer, so his ability and equipment is not in question.

Any ideas? Car is still at dealer and they are looking into it

 

Were the sway bars disconnected for the install?

 

I don't know - will ask. Actually, sway bars were on my mind too. They are factory 997 GT2 sway bars, adjustable.

 

I had some similar noises that were caused by 2 different sources. The end links were causing some noise and they also found the nuts on the top of strut towers were loose causing knocking sounds over bumps.

 

Link issue.

 

Thanks all for your help. Will pass on to my tech.

 

your car looks great, love black wheels on a white turbo

what kind of bumps cause the knocking and how fast are you traveling over the bumps when you hear the knocking?

 

I usually have to be going at least over 30mph, and is over sudden abrupt vertical movements such as deeper manhole covers.

Thanks for the kind words. The ADV wheels are actually a dark antique grey, but looks black in certain low light.

 

good clarification. Is the knocking a single "knock" or do you hear several knocks from each corner when you go over a bump at speed? If it is a single knock it may be a simple matter of the suspension and springs settling into their new position after the drop. However if it persists after ~100 miles and you are hearing several knocks over each bump then something may be loose or improperly installed.

 

One thing I have learned is to never overlook the installer regardless of qualifications. Ive had issues with dealer techs with 15+ years of experience twice now. Silly things like not torquing the throttle body hose down and it blew out on my 1m from the dealer!

 

+1.

Even the best can have bad days.

 

+2 had a Gold meister tech forget about my oil cap once found it in the engine bay a day later.

OP car looks great BTW OEM aero front lip??

 

I would also make sure the springs were installed the correct way - we have had cars arrive with similar issues and find the springs were installed upside down - the noise being caused because the spring is moving in the perch.

 

how is that possible they have totally different ends on top

 

Sorry, I didn't mean on a Porsche. The OP may just need a second technician to go over the springs while the car is lifted - see if something is clocked funny or loose.