Hi everyone! I currently seem to be hearing (and feeling) a loud clunk under my new 2015 STI. I know I should just carry it to the dealership but honestly I've always worked on my own Subarus and I'm 3.5 hours from my nearest dealer and I'd like to at least diagnose the problem before I take the car to them so that maybe they could order the parts or something to speed up the process hopefully so that I only have to make 1 trip. Anyways its a loud thump that I can feel in the floorboard that seems to be coming from the front or middle of the car. It does it under reasonably hard loads forward or backwards. It will do it if I give the car enough gas to really shift the weight of the car to the back or if I hit the brakes and shift the weight forwards. I can floor the car and hear the clunk and then it wont clunk again until I shift the weight forward (if that makes sense). Vice Versa if I hit the brakes semi-hard I can hit the brakes over and over semi hard and it wont clunk again until I go to hit the gas fairly hard and shift it to the back. Whatever it is,its something shifting forwards and backwards and doesn't do it when turning. I've never seen this exact issue on any of my other Subaru's before. anyone have any ideas on things I can check? I have access to a lift and tons of tools and I'm a pretty good mechanic. -Thanks everyone in advance!
yep my car has the trunk rattle but ive fixed it already. This is definitely something suspension or drivetrain related
Get underneath the car and look around. It's possible something wasn't torqued down properly at the factory and you just have a loose bolt or something. Check suspension components, sway bars, etc.
Actually did that yesterday. Didn't check everything but I did notice that the trans mount seems to have a lot of play. Is that normal? I'm talking an inch or so of play pressing against with lightly with a pry bar
From the symptoms you described I could totally see that being your transmission mount. Sounds like way too much transmission slop.... I'm willing to bet that is the issue
It didn't look broken or anything but I will check it out a little more when I have a chance. I took a video of it that I'll post when I can
Check the torque on your axle nuts. If they're loose they will cause a thump sound. This sounds like a similar situation. http://www.iwsti.com/forums/how-install/53796-axle-nut-replacement-got-click-knock-noise-try.html