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Strange Noise & Bump in Reverse

So I was leaving work tonite and was backing out of my spot with the wheel cut to the right. As I backed out I felt a "bump" and heard a "bump" come from the wheel area. Best way to describe both is like when you drive over a road reflector marker. The sound is similar and the bump vibration is close, not as abrupt.

I inspected everything as best I could and could not see anything. I went to open area in the lit and cranked it all the way to the right and did circles in reverse. Every once in a while the noise and bump would repeat.

I will stress that it was cold for TX, in the low mid 30s all day with a slight drizzle off and on. Could not repeat the house in a forward circle. I stopped in a lot on my way home and did a few reverse circles and could not repeat it.

I have stock wheels and Boss springs. My only performance upgrades.

Any ideas?
Interesting. I had a the same problem last month. My tires were shot, so when I had them replaced, I brought the noise to the attention of my dealer. After they replaced the tires and performed an alignment, they drove the car, then rode in it with me. We were unable to duplicate the noise. It has not reoccurred since (2 weeks/500 miles). I don't know if it was tire, wheel, or suspension related. I wonder if putting the car up in the air manipulated the front suspension in some way so as to make the noise go away?
I had the same situation a few days ago on a cold day here in San Antonio. The front tires almost felt like they were stuck and dragging. I was backing up on my way to get it aligned (after installing my coilovers) so I just figured it had something to do with that install. I haven't driven it since then so maybe it had nothing to do with the coilovers/lack of proper alignment???
Ok I knew that I wasn't (completely) crazy! Seems like a semi-common issue that might not really be a problem.


#LS-378 - So many Porsche's, so little time....
Pitt302 said:
My brake pads stick if wet ,when car sits for any lenghth of time.I always move the car the day after a wash or it sticks real bad.

This is true. Also, if you are using race pads in the rear without the spring retainers you can get some 'bite' onto the rotors when you go into reverse. I get it all the time but it causes no issues.

Champale said:
Ok I knew that I wasn't (completely) crazy! Seems like a semi-common issue that might not really be a problem.

Hmmm...all very interesting thoughts and ideas. I will test it out again after it warms up and everything is dry. I ran wider front tires on my 2008 Shelby and never had anything similar cold or wet. Just is very odd. If it repeats I will take it in.

There are no flat spots in my tires as she is my daily driver and my tires still have good tread.

Sounds like from everything it should not be too big of an issue. Thanks for all of the feedback.

Grant 302

basic and well known psychic
Darth Boss said:
There are no flat spots in my tires as she is my daily driver and my tires still have good tread.

I didn't mean that kind of flat spot from wear or lockup under braking, but the Pirellis are supposedly known for holding the flat spot on the tire where it contacts the ground if left to sit too long. I was guessing that this could temporarily be caused by the cold too.
Re: Strange Noise & Bump in Reverse

Wow! Thanks for the SVT link above. My LS makes the same sound twice a day: backing out of my driveway, and backing out of my parking spot at work. In both situations, the steering wheel is full lock right, and I get that clunk from the front right wheel. I was about to lift the car today and check out clearances.

via thumb power from my Pantech Discover
I had the same issue and after researching I found this regarding the lower control. So I took it in under warranty and had both the right and left side lower control arms replaced. Seems to been my issue but I have noticed a scrubbing sound but mine is due to the front tires being worn down and slipping.

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