So quickly I did research this awhile back and came across the fix for the hatch when it makes the "thunking" sound. Followed the DIY fix and it went smoothly and was done in twenty minutes. It didn't fix the problem. If anything it has gotten worse. Also on full disclosure I did a DIY clutch change, it was after this that I noticed the issue. I'm not sure whether it occurred after or before the change as the car was down for several months before I could fix it; and it was very intermittent and quiet at first. Also right after that was done I had an alignment done on the car (rough roads here in Utah) but the noise started before that so I doubt that is the issue. Oh the car is a 2006 CS only modification is the Tubi exhaust.
So on to the symptoms: So whats specifically going on is that when going over rough roads at lower speeds I hear a thunk-thunk noise in the back of my car, sounds just over my shoulder. It is intermittent but has become more common place. Whats odd is it is really bad when taking large bumps at low low speeds (as you should in a low, expensive car) and the slight deviations in the road at normal speeds. It completely disappears above 50mph no matter the road surface. That's it in a nut shell I'll make a time-line below with more information if you're interested or if you have experienced this and may know the solution. Oh and its a very solid thunk now, but i cannot feel it in the floorboards. I cannot feel it at all other than what you'd expect through road feedback.
As aforementioned I first noticed this about five months back after I completed a DIY clutch replacement. It was faint at first and very intermittent. It would only occur about once in three drives. You could almost never hear it unless you were really listening. It became more prominent and common so I was concerned enough to jack the back of the car up and try to find any issues or loose bolts, anything that could explain it. There were no obvious signs, the wheels didn't wiggle; and none of the bushings were worn. I am so obsessed with this car that I started to wonder if I was just going crazy. I had friend of mine drive the car(not a hard sell) while I leaned across the engine into the back of the car and I swear I could hear it coming from the hatch. This is also supported by the fact that even with the windows down the sound comes from behind me not outside. I have pushed down on the back of the car and sometimes it makes a sound but I'm not certain its the same.
Next
after much procrastinating I finally did the DIY hatch fix to no avail. I am going to tear down everything to the transmission and reassemble it this weekend, weather permitting. If anyone has had a similar issue let me know. Like I said whats supper weird is it totally disappears above 50mph.
I just wrapped up a clunk stopping change of sway bar bushings but it was the front. It sounds like you read my thread but I would look closely there. Your description does sound a lot like what my car was doing. With load on the bushings, it's hard to tell that there is play. I remember the day I actually felt and saw the movement with my hand on the bar/bushing while working the suspension. I knew I had found the problem and proceeded to drive the car for months after that with no real problem other than what became a really annoying clunk. I will say the car "feels" better with that play gone. Good luck, C.
Yeah I'm hoping that since it has been more pronounced since I last checked I'll be able to see it. Thanks for your input!
cannibalox, from yours and several other posts - it can be difficult to narrow down the source of the noise. YMMV with my comments....
The first clue that it is wear and tear related is that the sound is getting louder over time.
From the posts I've read it seems that the control arms and sway bar bushes are probably the best place to start.
As crispy mentioned, it can be hard to tell the condition of the bushes by visual inspection or jiggling it and some disassembly may be required.
Some of the bushes may have also hardened over time.
Oh and don't forget to check your dampers/absorbers and absorber mounts or strut mounts as you didn't mention the mileage and condition of the rest of the components.
for the rear - these are "over the shoulder" too.
other items you may want to check:
- condition of the trim pieces at the seat belt area (I had mine removed and reattached with some damping material to reduce trim rattle)
- anything in the compartments beside the engine area that could be moving around?
The vehicle has about 57,000 miles on it. That's the plan, as far as disassembly is concerned. It's due for its 60k service which I'll have done after the winter. When I have it done of I cannot find the issue by then I'll have them check. The front drivers side strut bearing is squeaking so I'll need to have that fixed as well. I'm doubtful of it being trim because i checked most of those as well. We have rough roads here in Utah and it can be murder on suspension although it was a California car until I bought it last summer. Thanks for the reply. Oh and condition. I'm super nuts about maintenance and cleanliness of it. I personally hand detail it several times a year. The only thing that's not flawless is where some a$$ hit my back drivers side
and drove off (It was in a parking lot) when I got back to the car the rear taillight was damaged and a small chip in the paint.
