2000 626 Tapping/Rattle When Hitting Bumps

[Coastie John]

All,

Whenever I hit a small bump there is a tapping noise that sounds like it is coming from both upper shock towers on the rear end. You can feel it also. There will be one to two loud taps/rattles after hitting the bumps. It doesn't look like the exhaust is hitting anywhere so I don't think it is that. Any thoughts?

Thanks....John

[Mark E M]

check exhaust again, closely.. pay close attention to the rubber gromets that hold up the exhaust in three differeny points. if any are broke it will rattle... also look at the heat sheild on the cat. converter, if loose it will transmit sound all along the exhaust.If nothing there then find a small pot hole and drive over it with one of the front wheels, then the other... if it rattles or clunks when you drive over the hole, your shock on that side is shot. Hope this helps..Later,,, Mark.

[Coastie John]

Thanks Mark. I'll double check the grommets. If I can pinpoint the discrep I'll post the results here......JOhn

[Coastie John]

Still chasing down the rattle. The exhaust grommets and cat shield were good. I did eliminate one noise. Turns out the chrome trim that goes around the tag lights/license plate area was loose. It had 4 broken plastic retaining pins. I super glued them back on and that worked.

I had to remove the trunk liner because water got inside and flooded the trunk. Turns out there are two 1/2" holes in the bottom of the spare tire compartment that are just taped over. The tape came off of one of the holes. I RTV'd and retaped both holes. Not sure if that was the leak. Waiting on the next rain storm.

Anyway, with the liner out and back seats down I can still hear the noise when going over bumps. More to follow.........

John

[Mark E M]

Coastie john, your leak will be (covered) well with that fix...Just occured to me that the rattle couls be the spare tire and the jack,where they are supposed to be locked down and the plastic top and threaded rod hold down the cardboard top could be the rattle.. just a thought.. Later,Mark.

[Coastie John]

Mark,

The leak is still there along with the noise. I have all the trunk items removed and drying out. We'll start with the noise. I have the carpet removed and with the back seats down the noise is coming from either the struts or one of the rear suspension components. I have been underneath the car numerous times staring at the different possibilities. It's tough troubleshooting without actually seeing what is thumping. All the bushings look ok.

We've been getting alot of rain the last few days (Oregon, where else!!). I looked inside the trunk from the rear seats while it was raining. The water is dripping in from what looks like the trunk seal area right above the latch mechanism. I pulled the seal, laid down RTV' along the metal lip the seal slides over and reinstalled the seal. I will let it sit for the night inside the garage with the trunk closed and check it in the rain tomorrow. I'm surprised this new of a car has leaks already! If it still leaks a new seal at the dealer is $54. That will be my next step.

John

[Mark E M]

Coastie, Try putting two jack stands under the rear axle, about 6 to 8 inches in from the wheels. start by having some one push down on each side.If not enough to make the noise then have them jump up and down on the bumper, be careful here,so they don't fall. It should be enough to find what is loose and making noise. Also grab each wheel and jerk back and forth to see if noise is coming from either wheel. Hope this helps. Later . Mark.

[mazdatech]

look at your rear sway bar you will see a link on each side that connectes the sway bar about 3" long or so ive seen these link wear out or break causing the noise your after

[Mac626]

I had a problem with a rattling noise on my '98. When the back brakes wear a lot, they clatter. I think this was due to the design of the calipers. There is a set-screw under a bolt in the rear calipers that limits the travel of the piston. It adjust with brake wear but at a certain point stops and the pads will rattle. To test for this tug lightly on the emergency brake when the rattle starts. If it stops immediately, this may be the problem.

[davisnfld]

Originally Posted by mazdatech

look at your rear sway bar you will see a link on each side that connectes the sway bar about 3" long or so ive seen these link wear out or break causing the noise your after

I had the same problem with my 98 last year and that was the problem. Dealer replaced link on one side and solved the problem. The noise is now back on the other side. So I guess it's time for another repair.

[Mark E M]

coastie john, Have you solved the problem yet?? been courious as to what you found. Later,, Mark

[BrySki]

Coastie, Is this noise intermittent...happens sometimes on our
DoubleOught. Only 60K on ours,how many miles on yours?
Mazda has a TSB on this issue but no proven single fix. To eliminate
"stuff in trunk" we've emptied the boot but noise still there...off/on!
Check out our Zoom/Zoom here http://www.cardomain.com/id/bryski

[Coastie John]

It took almost a 2 years but I finally found the culprit to the clunking noise. I read on another forum it might be the rear sway bar bushings. I changed them out and that fixed the problem.

[fuzzypuppy]

Hey there, I'm in Oregon myself though in Eugene, all the rain has made it difficult to fix my car as well, I'm ready to give up till spring.

[Coastie John]

A follow up. Still noise free. I forgot to pass the source of the water leak. It was from over spray by the Ziebart folks. They sprayed that sound proofing film along the inside of the trunk. It dripped down on the metal surface where the seal rests. I used some solvent to remove the film and that fixed it.

The next problem is the P0420 code. That will be for another thread.