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Porsche 993: Why is My Car Squeaking?

Noisy suspension is not only an annoyance while driving your Porsche 993, but can also indicate worn components in the steering and suspension system. Take some time to inspect your 993 for the source of that squeak.

By Joseph Coelho - May 12, 2015

This article applies to the Porsche 993 (1993-1998).

Given enough time, a recurring high-pitched squeak is enough to drive any car owner insane. In the case of the Porsche 993, the stock suspension components utilize a good amount of rubber bushings and ball joints that have the tendency to make noise over time. Given the age of the 993, it is prudent that the condition of the suspension components be inspected to ensure that you are getting the most out of your car. This article will examine the steering and suspension components that owners often report becoming noisy or squeaky on their 993s.

Materials Needed

  • Floor jack & jack stands
  • Tire iron
  • Torque wrench
  • Metric wrenches, sockets, and ratchet

Suspension Bushings

The 993 uses a large number of rubber bushings in the front and rear suspension components to achieve strength, while also limiting noise, vibration, and harshness. As with all rubber components, these bushings can age, dry out, or deteriorate, leading to less than ideal suspension handling and performance. Additionally, these bushings often can become noisy as the rubber hardens, which may be an indication that they are in need of replacement. The front lower control arms contain two bushings per side. Similarly, the rear multi-link suspension has bushings located in the track arms, toe links, and control arms for a total of eight bushings.

  • Figure 1. Front lower control arm bushings.
  • Figure 2. Rear suspension bushing locations.

Anti-Roll Bar Bushings

The anti-roll bar bushings are notorious for being noisy on the 993 models. As the suspension moves up and down, the roll bars twist and flex inside of the bushings. When the rubber bushings dry out or deteriorate, the roll bar will start squeaking. If the bushings have excessive wear, they will also be less effective at reducing body roll. Inspect the condition of both the front and rear anti-roll bar bushings. If in good condition, the bushings can be greased to promote smooth movement of the sway bars. Otherwise, replace the worn bushings with a new set.

Figure 3. Greased anti-roll bar bushing.

Ball Joints

The front suspension, rear suspension, and the steering all utilize ball joints to connect various components and allow for smooth movement. These spherical ball and socket joints are free to pivot in any direction which makes them ideal for use in the steering and suspension system. Unfortunately, these joints will not last forever and can begin to squeak and creak when their lubricant dries up or corrosion sets in. The ball joints can be visually inspected for tears in their boots that can allow moisture and debris to contaminate them and lead to premature failure. Additionally, the rubber boot can be felt and squeezed to determine if the lubricant has hardened, which can limit free movement of the joint.

(Related Article: How to Replace Lower Front Ball Joint in Porsche 993 - Rennlist.com)

Figure 4. Ball joints are used throughout the suspension system.

Struts

A squeaking noise emanating from the suspension struts (coilovers) can often be identified with a quick inspection. Check the springs to ensure there are no broken ends or cracks that could be causing them to bind and squeak. Similarly, inspect that each spring is properly seated in its perch; binding can occur if they are hanging up and not allowed to work freely. The strut top mounts can also become a noisy component in the 993. Some owners have reported a loose top mount making a squeaking noise in their cars, but was easily fixed by tightening them to the proper torque specification. The top mounts utilize bearings that can corrode or freeze up; however, they typically will not exhibit a squeaking noise. Nevertheless, it may be worthwhile to inspect the top mount bearings while examining the other suspension components.

(Related Article: How to Replace Front Struts on Porsche 993 - Rennlist.com)

Figure 5. Strut inspection.

Pro Tip

Stock struts on the 993 have been known to have a short lifespan of only 30,000 to 40,000 miles. The front top mounts will usually last 100,000 miles, but the rear top mounts usually have accelerated wear and last half as long.

Windshield

A notorious issue for the 993 is a squeaking windshield. For the 993 model, Porsche introduced a new, modern windshield that would fit more flush than the previous 964 windshield. Unfortunately, with the body flex of the car, the 993 windshield can squeak from the movement of the glass inside of its rubber trim surrounding. Many times, this throws owners for a loop and has them in search for a suspension squeak, when it is actually coming from the windshield. If your suspension components check out okay, the windshield is likely the culprit. Many owners have had moderate success spraying various lubricants between the windshield rubber to stop the squeaking. Porsche did issue a technical service bulletin and now have a rubber chord (Part #996 541 903 00) that is inserted between the the rubber trim to take up any space in the windshield and alleviate the squeak.

Figure 6. Rubber chord to prevent windshield squeak.

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