Help diagnosing a front end squeak

[geoff]

For the past several weeks, I've had a very annoying squeak that sounds like it's coming from the front of my car ('01 Boxster, 5 speed, ROW M030, 18" wheels, 64K miles). It's noticeable driving downhill on a twisty canyon road at around 20-30 MPH. Not a metallic squeak, but more like the squeak you get behind the dash on a new car from plastic rubbing against something. It seems to occur more when it's warmer, and isn't noticeable over speed bumps. It's either getting worse, or I'm just noticing it more and more.

I went to the dealer last week and the mechanic went with me for a joyride, but he couldn't hear the noise (I could). Based on searching here, the probable culprit sounds like the rubber bushing in the lower control arm. The mechanic plans to apply some high-tech grease to see if that solves the squeaking noise, at least temporarily, so we can identify if the lower control arm is in fact the problem.

Any other suggestions for diagnosing the problem? I'm guessing trying to touch only one suspension component at a time is probably the best approach for narrowing down the source of the squeak. Any secrets to quickly isolate the problem anyone cares to share?

If it is the lower control arms, is there any advantage to spending the extra $ on the GT3 control arms? Are they any stronger or do they wear better? Is it possible to replace the rubber bushings that wear on these in the future instead of having to buy all new control arms the next time?

[geoff]

After no response here and some suggestions / online diagnoses from a few other Porsche boards, I'm a lot smarter. My third trip to the dealer today might have solved my problem, though. On my second dealer visit, the head mechanic squirted some magic Wurth lubricant on the front lower control arms and sway bar bushings, then tightened the drop links and sway bars. Our plan was to lube/tighten one thing at a time. Unfortunately, the squeak remained and continued to get worse over time. I talked to Steve Alarcon at Johnson's Alignment, and he suggested retorquing everything to factory spec, as he's seen some fasteners loosen over time causing a squeak. I went back to the dealer this afternoon for the third time planning to just have them retighten everything, but the mechanic wanted to take another test drive first. As we started driving through the canyons at 30 MPH, he finally heard the sound (chatter/squeak/rattle). A few more miles through the canyons after doing lots of circles at various intersections, we were finally able to reliably reproduce the squeak (he was calling it a rattle at this point). After driving back and forth numerous times at the intersection of Mulholland and Decker Canyon (me driving, him standing outside), we got the car positioned at the right angle such that he could bounce the front up and down to cause the squeak. After poking around in the wheel wells and under the hood, he closed the hood and claimed success. Driving back to the dealership, the squeak was just about gone. When we got back, he popped the hood, adjusted the hood latch, squirted some WD-40 in the latch, and said the squeak was gone. Sure enough, I haven't heard it since.

The good, bad and moral of this experience:

I've got a great working relationship with the service department at my dealer. Two test drives, probably 3 hours of the head mechanic's time and a couple squirts of various lubes cost me exactly $0 dollars. I asked them to charge me for their time, but they didn't feel they did anything worth charging me. Is this a great way to build loyalty and repeat business or what?

I was almost convinced the problem was worn lower control arms based on numerous posts here and on other forums. I really want some of the GT-3 lower control arms now, but can't justify the cost now. The mechanic saw my notes on our test drive today and said he'd be happy to put them in, but I can't see spending a grand, give or take, when I didn't really have any suspension problem.

Several morals to the story - building a good relationship with a dealer (or independent) is invaluable, and trying to diagnose squeaks and rattles over the internet is potentially wrong and expensive.

If anyone is interested, my posts on other boards, including some good information on GT-3 lower control arms, can be found at:

Boxster Spec.com: GT3 control arm bushings vs. stock, Same or different?

Boxster Racing Board: GT3 control arms

Pelican Parts Boxster & Cayman Forum: Boxster front squeak