Before I provide any guesses or tear into it I thought it would be fun to collect a set of diagnoses from the Dorki Experts!
Car: 2002 Boxster S - Some Suspension Mods
Driver Experience:
Drives fine at and from SP HPDC to Berryville Grill with some possible spirited driving on the windy bits.
Reenter Route 7 heading east to DC. Notice when making a very slight right changing lanes a rhythmic bumping noise and feel in the wheel like a wheel/tire out of balance. Particularly it felt like the front left. Goes away turning sharper right or back to straight or any left turn. After the right hand off ramp onto the Greenway it gets much worse. Applying brakes appears to lesson the effect. I pull over. Check wheel torque - all fine. Check rotors and pads for signs of a broken pad or oddity in the rotors - all appears fine.
Post-Shadowing Note: Front-Left (couldn't see Front-Right) during the morning braking exercises were 'on fire' per stewards and 'showering sparks' per me watching - nothing felt/heard in wheel by driver/instructor and nothing identified as root cause at that time. Dismissed as foreign object
Reenter Greenway and the out-of-balance action starts to happen while going straight anytime above 40 and trying to drive faster than the harmonic does not make it go away. Begin the long, slow drive home to DC.
At some point on the Dulles Access Road it begins to be fine going straight at speed but still starts with any slight right. Brakes used to stabilize bumping. You would be amazed to know how few actual rights there are between SP and NW DC.
I have some thoughts on what I am looking for but was curious if anyone has seen this before or would like to make a suggestion that could lead to a six pack of beer for the correct answer.
Proposed Answers:- Wheel Bearing: BikePump, HoodPin, Rob VN, spiffyjiff, BobNovas
- Stub Axle Nut Loose: roundel
- Flat Spotted Tire: tdatk
- CV Joint: GaryGanoo
- Catastrophic Engine Failure Costing Thousands/IMS/RMS Failure: Casey914 aka BuzzKill91(4+4)Drover, NLuvWHisHands
- Wheel Weight Loss/Tire Slip - Out of Balance: Patrick3000, SJK (temporary FOD)
- Dumb*ss Owner Error: Vicegrip
- Brake Pads Eaten By Deer: jhsmith
- Cr*p Drover: Hunter, PerhapsOthers, sigh
- Will Not Be Tricked Into Compliance With The System!: Black Talon