Clank/clunk noise, very intermittent

[Emgee]

Hi Guys

From time-to-time, my 2007 GT-AWD CX-7 will make a clank/clunk noise which comes from the front-end. It happens in the following cases:

1) Car has been parked, I drive forward just a few feet (e.g. to the stop sign at the end of my street), I start to press on the brake and clank/clunk.

2) I'm pulling in to park at work; I pull in to the stall, put it in park, turn off the engine and when I release my foot from the brake the car nudges forward a bit (as normal) and I'll get a clank/clunk noise (not as loud as in case #1).

3) Sometimes when reversing out of a parking spot when I hit the brake to stop I'll get the clank/clunk; again, not as loud as in case #1.

All come from the front-end and seem related to having applied the brakes. I've taken it to the dealer and, of course, it doesn't happen. Which is the case, it doesn't always happen. I've been trying to find some situation in which it happens, but no luck so far. Currently I'm checking to see the position of the tires (using the tire valve as a reference) to see if the tires need to be in a certain position for this to happen.

The other thing is... once this noise has happened once it will not happen again for the duration of the drive. Or at least it hasn't so far.

Any one here have any suggestions as to what it could be? Perhaps I can ask the service shop to check it out on my next oil change?

Thanks for taking the time to read (and help).

 

[erhayes]

Not totally unusual. I suspect that the pads are shifting in the calipers. If that is the case then no problems other than noise. Another thought is loose wheel lugs.

 

[Emgee]

Hey erhayes

Thanks for replying.

If it's the pads can they do anything about it? I'll be having my tires rotated this fall, so they'll be off and can look at the brakes.

I checked the wheel lugs, they're secure. But I'll check again.

Thanks!

 

[offset_98]

Could be suspension as well...?

 

[Emgee]

@offset_98:

Thanks for the suggestion.

It could be... my struts have developed the "creaking/moaning" sound as the car takes dips and bumps in the road. Second time this has happened (within a year of previous strut replacement).

However, the clank/clunk/snap noise only happens with braking (and doesn't take much, usually when it happens I'm only applying the brake lightly).

 

[Emgee]

Does it happen on your CX-7?

Well, after a while I have two developments to report.

The first is that I can now recreate the sound consistently. I'll describe it below and it would be great if some of your here wouldn't mind trying it out to see if your CX-7 does it.

Start-up the car, put it in reverse and move back a foot or two. Brake normally. Go into drive, move the car forward a foot or two and then brake normally. At this point my car may make a clunk/snap-like noise, maybe not. Put it back in reverse and move the car back a foot or two, then brake normally. Now my car would definitely make the clunk/snap noise. Go forward again... snap/clunk. Go reverse again, snap/clunk. Comes from the front end, front wheels. The clunking/snap will happen only after a direction change. Once it makes the noise once in a given direction it won't make it again. You do not have to be moving fast at all, just drive casual.

The service center tells me it is the pads separating from the rotors.

Opinions? My concern is I'm only 5 months away before my warranty finishes and don't want to be told 6 months from now by the service center it really is something wrong and I got a big bill to pay.

Thanks all!

 

[offset_98]

I'm wondering now if its a transmission or engine mount.

 

[Emgee]

It only happens when the brakes are applied. Otherwise, if I just drive off in the current direction no noise is heard.

 

[vidor95]

Same problem here

It only happens when the brakes are applied. Otherwise, if I just drive off in the current direction no noise is heard.

My '08 CX-7 has the exact same issue. Did you ever find out what was causing it?

 

[Emgee]

My '08 CX-7 has the exact same issue. Did you ever find out what was causing it?

Yep, I believe it is the calipers (?) shifting in the housing of the brakes. Something to do with shims used in the brake assembly. In order to "fix" it, they had to install new brakes, couldn't just install replacement shims. Interesting thing though, my car is starting to make the noise again (after about 8 months or so). I've found the quality of parts/assembly on the CX-7 to be less than stellar.