Front Suspension - Popping Noise???

[95370]

Hello all,

I have a mostly stock 2015 FR-S. Manual 6-speed, stock suspension. Meticulously dealership maintained from new by my uncle, @etherdude, from whom I bought the car last year. It's up to 76k miles now.

The only mods I've done to it thus far are a full exhaust system (FT Speed cat'ed UEL header, and full Invidia exhaust behind that, ending in a Q300), drilled and slotted Stop tech rotors and stainless lines, and, recently, 18x8.5 Rota RT5's on all four corners, with Bridgestone S007A's in 245/35R18 size. This wheel/tire combination doesn't rub. This car is my daily driver, on some fabulous mountain roads in the Mother Lode region of Northern California (there is indeed gold in them thar hills!). I also plan on doing a few autocrosses (SCCA Fresno region), starting later this month (watch out, STX class!).

Unfortunately, prior to my installing the new wheels and tires, the car started making some odd popping noises, emanating from the front end. They seem to only occur at very low speed, when manoeuvering forward or reverse (i.e., changing direction). With the popping noise, comes a slight tic feeling in the pedals and steering wheel.

Any thoughts on the component at fault here?

I have put the car up on a lift, inspected the front suspension components carefully, and have not found anything loose or seemingly with unnaturally sloppy play... end links, ball joints, strut top hats, etc.. Any suggestions on what to check next?

I have a Subaru dealership local to me that could replace everything on the front end and charge me accordingly, or I can do the work myself, which I am equipped to do and quite comfortable with (30+ years of racing and working on BMW's, Porsches, MG's, Audis, MR2's, Miatas, water-cooled and air-cooled Volkswagens, and an ATS).

Thanks for your thoughts.

Dave

[DarkSunrise]

Sounds like you’ve checked all the usual suspects. I once had a similar popping noise after a track day that turned out to be a loose bolt on one of the underbody panels. Couldn’t believe it was something so simple but the noise stopped after tightening it down. Worth a shot.

[rbfr.s]

I had the exact same issue a few days ago (mind you my suspension is all modified). The culprits of my popping were the firewall strut bars and endlinks. The undertray, as @DarkSunrise mentioned, is also another area to inspect.