Clonking / Knocking going over bumps
 

HI, I have a 2007 231 6 speed Manual UK RX8. I have a clonking noise when I drive over bumps with the left wheel (i.e man hole covers) and rough surfaces but bigger bumps and general dips in the road don't do it. I have attached a recording which I made from inside the car as the noise seems to travel though the steering wheel and you can also feel it in the wheel.

I own a garage so I have had this car in the air on our lifts to check the steering and suspension and I have got to say I cannot find anything wrong. All bushes are fine and there are no loose bolts.
SO guys i'm stuck, I dont really want to take my car into the dealer as I cant see what else different they can do that I havent already.

I must also point out that this car has only done 5,940 miles so I doubt anything is worn.

Any ideas?

check the tq on the wheels. should be 108 ft lbs.

i might be corrected on this for a 07.

beers :beer:

I have had both front wheels off while looking at the suspension and I tightened to 110 ft lbs.

do you have aftermarket springs?

No the car is totally stock

the torque on the front sway bar end-links?

or possibly this...

http://www.finishlineperformance.com...05-08-1948.pdf

Thank you for your post, I hadn't seen this Mazda bulletin.

I'm afraid it's not the end-links as I removed them and drove the car a short distance and it still did it even when they were disconnected

This might be too easy but last time this happened to me It ended up being a tool I left under the hood on the left side.

check the fronts..

btw, you recorded it with the microphone where???

beers :beer:

I recorded it with the microphone inside the car around the back of the steering wheel as I think the noise is traveling up. I tried recording it outside i.e microphone on the shock absorber but there is too much other noise to hear clearly what is going on.

Could by any chance it be the shock absorbers? Would I feel it through the steering wheel?? I have checked the steering rack mounts and they are perfect

No tools left under the bonnet as the car has hardly had any work done other than a couple of oil changes

sounds like a plastic moving around to me

The knock is quite heavy sounding and I have tried removing all the covers from under the bonnet.

I cant find anything under the dashboard that would make a noise which can be felt in the steering

hmm, I don't know... I guess the shock or spring isn't a bad guess, is it seated properly?

I'd try retighten everthing suspension wise. How about the tower bar, and all the nuts that holds all the shocks, I remember mine would make a popping sound when I twist the chassis turning in to a steep hill.( you know how one wheel would start climbing the hill before the other wheel )

I will give that a try and let you know. It is booked in with the dealer for the 29th September but I would like to find the problem myself in the mean time :)

I had to look up what a tower bar is. I think in the UK we call it a Strut Brace

Last time this happened to me the dealer had left 3 loose bolts on my suspension, and the noise was very similar to yours, however mines were on the left rear side of the car. I also thought it was coming from the front of the car until I had some1 seat back there. you might want to check the rear.

maybe like a sway bar bushing

My car has only been to the dealers once for its first service which is basicly just an oil change and check the levels so its not like they have done any work on the suspension.
Its definitely coming from the front as I have people sit in the back to verify this

With regards to the Sway Bar I've checked all the bolts on it and they are all tight.

Put more lube on the front anti sway bar

i had the same problem and it came to be the bushings on both sides after greasing these bushings the noise went away.they only made a sound when going over speed bumps and slight ground height differences.tbecause of all the rain in the area they were preety dry. hope this helps!

Thank you for your reply at least I'm not alone with having this noise.

I disconnected the sway bar both side from the wishbone and the noise was still there :(

Yep same. Grease the sway bar bushings. Did it 6 months ago and have to do it again :(

yea double check that nothing is loose under the hood and hitting up against it and check the strut mounts to b sure they are ok....not sure if u did that or not

I would check the top strut nut on the strut. If it's not tight the strut can go up a little and knock over a bump. It will appear tight. but check it anyway.

Hello there, did you ever figure out where and what problem was? I might be having the same issue right now but I'm pretty sure mine is coming from the rear left side. I removed the rear left tire and examined it and couldn't find anything wrong but if I had to guess I'd say the bushing might be the problem. But please I'm open to hear your experience and solution