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  July 20, 2010 4:13 p.m. RexSeven Dork

  I don't think my '07 Mazdaspeed3 escaped last weekend's New England Forest Rally unscathed, despite it not actually racing. I had to drive on a lot of the stage roads to get to my work assignments, and many of them were long, rocky, dusty logging roads with many inclines. At one point I heard two very loud "BANGs" that made me think I busted my oil pan, but there was no discernible damage aside from some scratching on the plastic side skirts.

  Today I noticed my MS3 was acting like it had a bad wheel bearing while on the highway (i.e. making noise when turning right, but not left). Near the end of my 35mi trip to work, I noticed it making a loud thumping noise when decelerating, no matter where I pointed the wheels. The car did not make any of these noises before the rally, so I assume something got damaged on the stage roads.

  Any ideas? Do you think it will survive the 35mi trip back home tonight? It has an extended warranty and roadside assistance, so I'm already penciled into the dealership for Thursday morning and if it breaks down, I can get it towed to the dealership.

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  July 20, 2010 4:20 p.m. mndsm HalfDork

  Did you bend a dust cover? I did mine similar on some gravel "roads" on my way to a cabin. Other thought might be a cooked endlink....

  And the BIG question- did you have have the TSB for the motor mount done? Stage roads would certainly be detrimental to that mount (the bolt for it wasn't loctite'd or something along those lines, and was prone to backing out, and shearing off- mine did it). If not, I'd probably not drive it until it hit the shop, or at least be careful, because when that mount fails, it's bad news.

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  July 20, 2010 4:36 p.m. RexSeven Dork

  The motor mount was actually a safety recall, and according to the dealership when I bought the car, the recall was done. I haven't looked under the car since the rally after I heard the bang noises, but I doubt it's a dust cover due to the severity of the noise and the slight vibrations in the steering wheel.

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  July 20, 2010 4:47 p.m. mndsm HalfDork

  Which side of the car was it on? If it's the MM, it'll be on the left.

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  July 20, 2010 4:52 p.m. RexSeven Dork

  The thumping noise at deceleration is kind of loud so it's hard to tell which side it is coming from. When driving straight with some gas on, the noise behaves like a bad front wheel bearing on a rear-wheel drive car like I described in the OP. That's the best I can describe it since I've had bad front wheel bearings on my RX-7 before.

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  July 20, 2010 8:02 p.m. RexSeven Dork

  I took the car to and from the convenience store about 1/4 mile down the street from work to pick up some dinner and to try to notice anything I've missed. I can't hear the thumping until I coast/decelerate from 40mph, then it is very faint. It was very noticeable when coasting/decelerating from highway speeds (55mph or higher) earlier on my way to work. I think I also hear a clicking when parking with wheel at full left lock (didn't test right). There definitely sounds like some metal-on-metal rubbing like the brake heat shield rubbing against the brake rotor.

  It's getting dark here and I left my flashlight and 1/2-drive ratchet set in my RX-7, so I'm not going to be able to do any looking under the car or any quick repairs. Since I go home at 12am, I can take it easy going home since there aren't nearly as many M@$$holes trying to run me off the road as during the day.

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  July 20, 2010 9:18 p.m. hank

  You should try looking at the dogbone mount under the car. They tend to be traps for dirt and gravel, which can then make those noises.

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  July 20, 2010 9:21 p.m. RexSeven Dork

  By the dogbone mount, do you mean the rear motor mount?

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  July 20, 2010 9:34 p.m. hank New Reader

  Yes. It has a 17mm bolt that goes through it, and the mount sits in a pocket.

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  July 20, 2010 9:35 p.m. RexSeven Dork

  I will check that, then. I have a CP-E 75-duro rear motor mount in place of the weak-sauce stock part.

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  July 20, 2010 9:43 p.m. irish44j HalfDork

  any possibility you busted a CV boot? If you did it early in your off-road trekking, crap (rocks, dirt, debris) could have gotten in there and trashed the CV joint....while definitely making a clicking or thumping sound.

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  July 20, 2010 10:01 p.m. RexSeven Dork

  Possibly. I will be able to have a look under the car tomorrow or Wednesday to see if I can find any damage. I was able to get a quick look under the car during the rally but it was mainly to look for any punctures after hearing the BANGs. I didn't hear any of the thumping until today.

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  July 21, 2010 2:39 a.m. Strizzo SuperDork

  If you bottomed the car out, you could have tweaked the exhaust enough for it to be contacting the body when you get off the gas. Accelerate up to mid/high tons then let off without pushing in the clutch. If you letoffquick enough you should be able to hear it bang in the body.

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  July 21, 2010 9:30 a.m. Xceler8x SuperDork

  After my first track day in my 2007 MS3 I noticed a thumping sound from the rear. Sounded like something moving around in my hatch. Turns out it was a sway bar mount that had worked it's way loose on the track. The dealership tightened it up and it's been ok since. 40k miles later.

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  July 22, 2010 3:40 p.m. RexSeven Dork

  Dealership says it's a bad front left wheel bearing. I suspected a wheel bearing at first but the noise got so loud I began to think the issue was much worse. Doesn't mean there isn't anything else going on - I will get the MS3 up on the ramps this weekend - but it looks like it isn't as bad as I thought. All of a sudden that extended warranty I thought I'd never use makes perfect sense.

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  July 22, 2010 10:44 p.m. digdug18 HalfDork

  I'm kinda surprised that it was covered under warranty.

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