My car (2012 G37S sedan) is bouncing slighly fore and aft after coming to a stop. Thoughts on what it could be? I installed PowerTrix coilovers 4 months ago, so perhaps the car being a bit lower, plus the stiffer suspension, has put additional stress on 14 year-old, 94k mile bushings?

Other than this fore-aft bouncing when coming to a stop, the car's ride and suspension feels smooth, tight, and controlled.

 

Well, funny story, this was a case of a silly mistake on my part. I had one rear coilver set nearly full hard on compression, while the other was set nearly full soft. My intent was full soft, so I must have neglected to check one of the shocks when I installed it. Fortunately it was relatively easy to check and fix this while swapping over to my summer wheels and tires as the rear shocks are easy to remove.

The good news is I am aligned and all the bushings are still in good shape.

 

Tohle chování po zastavení často ukazuje na kombinaci věcí, ne nutně jednu jasnou závadu. Ano, coilovers a snížení auta můžou změnit geometrii a zatížit starší silentbloky, takže to lehké „houpnutí“ dopředu/dozadu se může víc projevit. Ale u G37S se to často potkává i s unavenými silentbloky zadní nápravy nebo diffu, případně lehce měnícími se otáčkami při doběhu automatu po zastavení.

Důležité je, že jinak popisuješ auto jako pevné a kontrolované, takže to nevypadá na katastrofický problém. Spíš bych zkontroloval zadní kontrolní ramena, diff bushings a správné dotažení a usazení coiloverů. Pokud se to zhorší, diagnostika geometrie a vůlí v podvozku to rychle odhalí.

 

this sounds like a front lower control arm bushing/rubber that ripped. it's the main/large/posterior bushing. took me a while to figure out. i got lucky honestly... once removed, somehow twist or bend the bushing to expose the tear(not easy), otherwise it looks normal. only my driver side was torn. i replaced both, starting with the passenger before finding out that the driver side was bad. no more fore-aft bounce after stopping.