Mazda CX-7 Noise and Vibration

maavalousmaavalous Member Posts: 17
Hey... HELP!

I have a 2008 GT AWD (bought in in April) and it is exhibiting a "harmonic vibration" throughout the car at highway speeds. It is worst between 55 and 80 mph. It smooths out, but is still noticeable between 80 and 110 mph.

Clearly a difference between "coasting" and under power... worse under power/torque. After 100 miles on the interstate... I feel like I'm sitting on a massage seat :o(

Dealer has tried:
Tire rotate and balance - nothing odd found... no help.
Replacing the drive shaft - a 3-piece monster... no help.

I have tried simulating the RPMs in different gears and the vibe only appears at highway speeds not highway RPMs. Obviously, can't easily test gears lower than 5th or 6th gear at 75 mph.

Oh, and no noticeable vibe in the steering wheel specifically... allignment seems spot-on... it's the whole car that vibrates.



  • zewie1zewie1 Member Posts: 5
    So i purchased my Mazda CX-7 just under a year ago and about 4 months ago it started to make this very loud ticking, clanking noise (lost for the proper comic sound). this noise comes and goes very quickly only when accelerating. i cant reproduce this noise for the technicians while i just sit there and look like an idiot with my lips flapping trying to get my point across. the technicians say they will take a look and have come up with no answers. so now im stuck with a car that has an apparent problem but no way to diagnose it.... anyone out there have any of the same issues..or can help... by the way this is one thing that is not tripping the CEL...imagine that!
  • zoom49zoom49 Member Posts: 76
    Sounds like it could be knocking (detonation)due to either lack of premimum fuel, or it"s possible you have an early build CX-7 that need the ECU reprogramed. We have always used premimum gas but just had our ECU updated. If when you back off the gas the noise goes away, this is the most likely issue.
  • outbackeddyoutbackeddy Member Posts: 7
    If it is gas related, you should be able to demonstrate it to the dealer. I think we need more information to assist you in trying to determine a cause. Ed
  • zewie1zewie1 Member Posts: 5
    ok so i admit i dont use premium fuel, but splurge for the synthetic. but in fact the noise does go away when i lay off the gas. the technician test drove the car and he wasn't able to recreate the noise. and i tried numerous times to get it to make the noise while another person was in the car and still couldn't make the noise. it as if the car has a mind of its own and only does it when it wants to.. by the way thanks for the help any new ideas.........?
  • zewie1zewie1 Member Posts: 5
    what is ECU?
  • carlitos92carlitos92 Member Posts: 458
    ...splurge for the synthetic what? oil?

    that's probably a good policy - but most likely unrelated to the noise you have.

    what i would do is run a tank full of 93 octane gas in the car and see if the noise disappears. run the tank as empty as you can before putting the premium in.

    detonation is temperature-related as well, so it may be that when you visited the dealer, it was cooler?

    incidentally "ECU" is the engine computer... manufacturers can change fuel delivery, timing, and all sorts of things just by reprogramming the computer. with the 2007's, mazda upgraded the software at least once to diminish turbo lag symptoms.

  • anxsanxs Member Posts: 7
    Has anyone experienced mirror vibration? When my car was delivered the driver side mirror shimmied and it gave me a headache to look at. Not only that but any time I listened to the stereo with the slightest bit of bass in it it would vibrate real loud. Part of the reason I choose this vehicle was because of the stereo package and I can't even enjoy it. They replaced the whole mirror assemply once and it's only slightly better than it was before. What should I do now? I'm sure they think I'm insane.
  • apattapatt Member Posts: 1
    Has anyone else noticed a wobbly or bumpy feeling while driving the cx-7? I test drove 2 different 2008 cx-7 sports both were front wheel drive. Only diff was one had a power seat and the other didnt. The car without the power seat drove a lot rougher than the car with the power seat. Is it possible that it is just my imagination?
  • vbbuiltvbbuilt Member Posts: 498
    The only way you can tell if it's NOT your imagination is if you drove both vehicles over the exactly the same route, same driving conditions, same speed, traffic conditions, etc. The presence or lack of an accessory, does not make a difference in suspension, drive train or engine, in the FWD sport.

    What I'm thinking is that you may have actually stumbled onto a problem, peculiar to that that one unit. Recommend you go to another dealer and test drive another vehicle and see if you notice the same problem.

  • morrison0880morrison0880 Member Posts: 4
    anxs. I am having the same problem with the vibrations from the Bose. For me it is mainly coming from the door armrests, both driver and passenger. Right by the window controls. I upgraded to the Bose for the same reason and now it drives me nuts listening to the vibrating, which isn't quiet by the way, but really loud! Dealership said that there was nothing they could do about it. If anyone else hase run into this problem, let me know, and if there are any fixes I'm all ears.
  • vbbuiltvbbuilt Member Posts: 498
    I have the tech package as well. It's not your imagination and there is a fix, but don't expect Mazda to do anything about. My dealership tried to fix it, but couldn't. It's the material in the door panels, which vibrates at low frequencies, such as strong bass. In my ride, when the doors were closed, the low frequency vibration was barely noticeable. But if the doors are open and I crank up the volume, the vibration in the door panels was horrible!

    The fix is to go to an audio dealer and get DYNAMAT installed. I did and it makes a huge difference. Got rid of 90% of the vibration and also provides a measure of sound insulation from the exterior road noise. Cost me about $300 for both front doors, where all the vibration was coming from. Audio shop told me that they could do the entire car for about $700, which I'm considering.

    Hope that helps! Vince.
  • morrison0880morrison0880 Member Posts: 4
    There is a little annoying rattle in the door, that I'm going to have checked out, but the vibrations I'm hearing with the stereo aren't coming from inside the door, but rather from the plastic moulding by the window controls. I can physically push in the moulding, and when I do the vibrations lessen, since I'm tightening the contact between the two plastic pieces, but don't entirely go away. The arm rest for your elbow near the back of the piece is made out of cushioned rubber and that area doesn't vibrate at all. I don't know why they didn't manufacture the entire top of the piece out of this rubber, or at least put a piece between the plastic components to dampen the vibrations. Probably has something to do with cost, but for such a small piece, that doesn't make sense for the cost of the vehicle.
    This is the first new car that I've bought, and although the rest of the vehicle is outstanding, this minor problem is a major disappointment. Takes away a lot of the fun of driving it, and I'm not sure anything can be done about it. I sent Mazda a nasty email, and I bet I get back some automated response. "Thank you for your feedback. We value our customers and their opinions. BUY THE NEW CX-9, SUV OF THE CENTURY!!!!"
  • kkearneykkearney Member Posts: 4
    OK, here goes: 2007 GT. Bought 2nd hand from dealer with 12k miles, now have 26k. Since purchase have had a vibration I can feel through the steering wheel at almost exactly at 30 mph, lasting a few seconds, then dissapearing.

    I've replaced the tires, which helped with handling, but the vibration remains. Once the tires were replaced I now get a shaking from ~58 to 62mph, which also dispappears. At all other speeds (up to 100) the car is solid - no shaking...

    I return to the dealership figuring the tires are slightly off-balance... BUT, am told they are dead-on. When I ask about both vibrations I'm told that this is inherent in the car itself due to a short wheelbase, yada yada yada. Further, he explains that mine rides like a Cadillac compared to others in their inventory and that the '08's are worse! Now, I've owned a number of small cars including a Ford Fiesta (yikes), Accords, and a VW GTI. NONE (including the Fiesta) shook like this one...

    So, my questions to the group are:
    1) does anyone else feel a momentary vibration in the steering wheel at ~30mph?
    2) How about vibrations and shaking in general? Have you had any you can't seem to get rid of?
    3) How has your dealer been to work with? Is it time for me to find another dealer to look at this?

    You help/feedback is appreciated. Thank you
  • dmele426dmele426 Member Posts: 33
    I owna 2008 cx-7 awd-GT, I had the car for about 6 weeks (1500 miles later) and the car has developed a rattle or squeek as if some panel is loose within the passanger cabin / front right side. I cannot figure what it is??
    anybody has the same problem, I can hear the noise specially over bumpy roads, i am heading out to the dealership in NYC-Long Island area to see if they can find the source.
    Anybody has any idea what it could be, worst yet i am afraid they may not even know what it is.
  • slw5slw5 Member Posts: 19
    That is what mine does. I call it a metal clanging rat-i tat-tat sound and then black smoke blows out the back only when accelerating and at any speed and never once tripped the CEL either. I have several posts on this website about it. I also have an extremely strong turbo lag which has put me in life threatening situations. Mazda told me it was not predetonation ping (it never even sounded like that anyway) and they didn't know what it was so they "red lined" my vehicle and notified Mazda to find a fix for it. That was October.

    Very rarely, I am able to duplicate the problem and thank heavens a technician finally drove with me and witnessed it and it was just minutes after it occurred on the way home from work. Next time it does it pay attention to what you are doing. Mine happened quite often after a new tank of gas but not always and I could be going 45 or faster . . . it's ridiculous.

    So a couple of days ago I contacted a lemon law attorney and they say I have a good case since I have been complaining about this since the first few months I owned the car and Mazda hasn't found a fix for it. I'll know the results in about 30 days. Needless to say, I've parked the car in the driveway and am not to drive it another mile till it's resolved.
    It truly saddens me because I love the way this car looks and when it's not lagging or making that noise with the smoke it's truly a fun car to drive. And, If this case works I'm not even sure what I want. Dare I stay with Mazda and choose the CX9 .. . not sure. I've owned Toyotas forever and never had a single problem. I realize that the 2007 CX7 is new technology and maybe that was my mistake. .. the bugs hadn't been worked out yet.

    Good luck on your noise issue. I sympathize with you.
  • jjvanjjvan Member Posts: 1
    How did you make out with your noise morrison0880 ? I have a 2007 cx-7 and have the same noise, on the same side, since I bought the car. It seems to start when I drive over 60 mph. It sounds like it comes from the door panel, but Im thinking its comming from the roof rack slots above the window. They do make alot of noise when you tap on them. I had the dealership look at it a few times, and they don't know where its comming from. All they say is that its wind related. I don't want to mess around too much and make even more rattles, so I just drive with the radio on when I drive over 60.
  • kcrnmalekcrnmale Member Posts: 47
    This was a common problem when I owned my Chrysler 300C. At the same mph you mentioned, the engine causes a harmonic vibration through the exhaust system sort of like a tuning fork. It tends to be felt at specific speeds but disappears otherwise. Not sure if this is the same, but it may explain your vibrations.
  • sueb613sueb613 Member Posts: 3
    I am curious if this has been solved. I have a 2008 CX7 and the vibration occurs at 58 mphand disappears around 75 - 80. It is in the steering wheel.

    I have had the car for one month and it has been in service for half that time. They replaced the tires, 4 wheel balance, etc. Didn't work.

    Now they think it has to do with the transmission because that is the last speed it shifts at. They have replaced many parts but it is still there - so they tell me.

    Now they are replacing the transmission mounts.

    IF this doesn't work, we will be filing under the lemon law.

    Does anyone have any other ideas?
  • jennholl02jennholl02 Member Posts: 2
    I have a new 2007 CX-7...have owned it for 10 days and it's already been in the shop for 3 of them.

    It drives great until I reach about 70 mph and then I get an incredible shaking/vibration in the steering wheel. It's been aligned (still pulls to the right), tires balanced and had 2 tires replaced due to "flat spots" from apparently sitting on the lot. And it still vibrates.

    Anyone else have this or similar issue? Any suggestions? :confuse:
  • sueb613sueb613 Member Posts: 3
    Is your's a new 2007 or 2008? Mine is a 2008, and I have owned it for less than 1.5 months and has been in service for about 15 days of that.

    I now have Mazda corporate involved. They have no clue what it is. They had me drive another new car to see if it has the same problem. While there is a certain amount of vibration in the steering wheel of all these cars, my car's problem is more of a harmonic vibration that you feel all through the car starting at 58 mph. If you sit in the back seat (which I tried) it actually vibrates all through your body like a low rumble.

    They are now suggesting it has to do with the "torque converter."

    Waiting for the Mazda "engineer" to get around to looking at it. This is not a normal feel or sound, and they have now had their third try at it.
    As I said earlier, I will shortly be filing under the "lemon law."

    I would suggest you stay on top of it with your dealership. I will bet there are a LOT of these cars with this problem around.
  • jennholl02jennholl02 Member Posts: 2
    It's a new 2007...the dealership had it for 4 days...they supposedly fixed the vibration with a wheel alignment (still pulls right) and 2 new tires. But, I still have the vibration over 70 and now my check engine light is on...less than 12 hours after I drove away from service.

    My vibration is felt mainly through the steering wheel...I don't believe that it can be felt in the back seat or passenger seat, but you can physically see my arm start to shake as I approach higher speeds. Have driven it on various roads/highways to ensure that it's not road specific and have had husband and sister drive it to ensure it's not "driver" error (which I love to hear :mad: )
  • maavalousmaavalous Member Posts: 17
    Hey... HELP! :sick:

    I have a 2008 GT AWD (got in in April) and it is exhibiting the same sort of "harmonic vibration" throughout the car at highway speeds. It is worst under power/torque and between 55 and 80 mph. It smooths out, but is still noticeable up to 110 mph. Clearly a difference between "coasting" and under power.

    They have tried:
    Tire rotate and balance - nothing odd found.
    Replacing the drive shaft - a 3-piece monster... no help.

    I have tried simulating the RPMs in different gears and the vibe only appears at highway speeds not RPMs.

    Oh, and no noticeable vibe in the steering wheel specifically... it's the whole car.

  • sueb613sueb613 Member Posts: 3
    OK - you MUST call Mazda corporate headquarters - they are extremely responsive. This is exactly the problem I had, and it was finally solved by replacing the drive shaft. They had done everything up to that point including 4 wheel balance, new tires, front end alignment, yet the car still had this harmonic vibration that went right through your body from the steering wheel. It was especially bad in the rear seat - I know because I sat back there and couldn't believe what it felt like.

    I am convinced that Mazda got a batch of bad drive shafts -as my son who is a mechanic diagnosed the problem right at the outset.

    DO NOT STOP trying as it can be fixed. For information purposes, mine was fixed at Suburban Mazda in Farmington Hills, MI. They sent in the regional engineer to figure it out and didn't stop till it was solved.

    In the long run, both the dealership and Mazda were excellent about taking care of the you can get it fixed.
  • maavalousmaavalous Member Posts: 17
    It is a bit mind boggling that my dealership couldn't find anyone that was aware of this or that it wasn't already out as a TSB!!
    I think the serious vibration problem may have been fixed by replacing the tail shaft. I need to give it another 1,000 miles with no serious vibe to be certain... the original vibe didn't become apparent until around 1,000 miles. Since I now know that Mazda got a bad batch of shafts I can't be positive, yet, that the one they installed isn't also one of the "bad" ones. Statistically, it is possible.
    There is still a vibration in the car at highway speeds. It is clearly not as bad as before. Not sure what to attribute the remaining vibe to... tire, motor, suspension, overall design... very hard to say. I have a sneaking suspicion it may be related to the combination of 6th gear and low RPMs (which is great for gas mileage but is the rough-running range for a 4 cyl. motor). It seemed to be less noticeable if I manually shifted down into 5th or 4th while maintaining same speed. So, this may be a "design choice" and nothing "fixable". But, unlike before, I can get over the reamining vibe in time :o)

    Thanks for your reply and help!!
  • maavalousmaavalous Member Posts: 17
    Guess I jumped the gun... replacing the tail shaft (drive shaft) does seem to have fixed the problem.

    It is a bit mind boggling that my dealership couldn't find anyone that was aware of this or that it wasn't already out as a TSB!!

    I need to give it another 1,000 miles with no serious vibe to be certain... the original vibe didn't become apparent until around 1,000 miles. Since I now know that Mazda got a bad batch of shafts (confirmed by a lady in MI that had the same issue) I can't be positive, yet, that the one they installed isn't also one of the "bad" ones. Statistically, it is possible.

    There is still a vibration in the car at highway speeds. It is clearly not as bad as before. Not sure what to attribute the remaining vibe to... tire, motor, suspension, overall design... very hard to say. I have a sneaking suspicion it may be related to the combination of 6th gear and low RPMs (which is great for gas mileage but is the rough-running range for a 4 cyl. motor). It seemed to be less noticeable if I manually shifted down into 5th or 4th while maintaining same speed. So, this may be a "design choice" and nothing "fixable". But, unlike before, I can get over the reamining vibe in time :o)

    I'll only post back if it isn't actually fixed...
  • deezozdodgedeezozdodge Member Posts: 4
    Do the test: raise the car up on jackstands. move the tire and wheel with your hand up and down and side to side. check for play. you should not have any play. if you do have play, look carefully around the ball joints, tierod ends and inner tierod.

    mine was inner tierod bushings. a $15.00 part and easy fix...
  • p100p100 Member Posts: 1,116
    I do not own a CX7, but I have had my share of vibration problems with a 1992 Mazda Protege and 1999 Mazda 626. Both of these cars exhibited steering wheel vibration that was caused by substandard CV axles installed at the factory. Replacing the axles helped, but did not totally cure the problem. At least I did not have vibration under acceleration, which was caused by defective inner CV joints. I am so annoyed with this that I have no intention of buying another Mazda vehicle. Ever since this company was taken over by Ford, they started using crappy parts.
  • maltbmaltb Member Posts: 3,572
    Ford bought controlling interest in 1997. How did that affect your '92 Protege?
  • sweetie12sweetie12 Member Posts: 8
    I have had my 2007 CX-7 for 1 year and have had a noise under the front end for about 9 months. I first thought it was due to the cold winter months, but I still have it. I had the car in a few weeks ago to have the motor replaced in the sunroof (apparently I'm not the only one) and for this noise. It sounded to me like a noise in the shocks, struts, ball joints, something to that effect. I took the mechanic for a long drive over speed bumps, etc. and he said it was the bushings in the stablizer bar making the noise. They replaced the bushings, but I still have the noise. Is anyone else experiencing this type of problem? It's really irritating!! :confuse:
  • maavalousmaavalous Member Posts: 17
    Well, so far they have...

    Balanced/rotated tires 3 times. Admitted the Goodyear Eagles are very soft and prone to cupping but mine aren't bad enough yet to be the vibe cause... only 4,300 miles.
    Replaced the tail shaft (engine to rear differential 3-piece).
    Done 4-wheel alignment.
    Put "special" synthetic lube in rear differential.

    Although the tail-shaft made a big improvement. The vibration is still there... just not as bad. I've driven a front-drive CX-7 to compare and no such vibe. Also driven Nissan, Hyundai, Audi and Acura with no vibe.
    They tested it without the tail-shaft (I didn't get a chance) when they swapped it and the vibe went away. So, clearly, there is an issue with the Mazda AWD system.

    We're still working on it... I have to say, they (both dealer and Mazda) have been great about it so far.
    I'll continue to update until it's fixed or I trade the car :(
  • weinerdowndogweinerdowndog Member Posts: 13
  • maavalousmaavalous Member Posts: 17
    Sadly, I have to report no progress. The car still vibes at highway speeds. I have contacted MazdaUSA. Again, everyone is friendly and helpful... just not able to stop the vibe even with the help of the Mazda "master technician".

    There are only 4 components that are different from the standard AWD car. Since they have not said... "it's the xxxx part and we'll replace it now and you'll be all set" I have to assume there is something very wrong with how Mazda implemented AWD.

    I'll post more updates until it's fixed, or sadly, I trade it for something else.
  • maavalousmaavalous Member Posts: 17
    DO NOT BUY A MAZDA CX-7 with AWD!!!

    Final update on my vibration saga…
    The last part they replaced was the rear driveshaft (tailshaft if you will). That knocked out about 40-50% of the vibe. Same result they had on at least two other cars I know of.
    I asked them to do better… obviously. We had gone from teeth-chattering vibration to very annoying vibration at that point.
    They had a team of Mazda engineers in Houston from Japan for a meeting. They spent 2 full days with the car. They did some form of elaborate balancing on the tailshaft. End result, maybe another 10% reduction at best.
    Realizing they hadn’t gotten rid of it, they next brought in an NVH Engineer (noise, vibration and harshness). They loaded the car with test equipment for a couple of days. In the end, they did nothing to improve the situation.

    So, I asked Mazda to trade with me for a new car of the same type. This is when it gets GOOD…
    They came back and said that putting me in a new car would not solve the problem. That the vibration was “normal” in their opinion.

    So I asked them for a refund… gee, what a surprise that they would say NO.
    So, I will pursue the Lemon Law on this for a bit. But, the Texas Lemon Law was written by the car dealers (gotta love Texas politics) and you have almost no protection. We’ll see how far I get but I may be stuck with a LEMON!!

    Bottom line, Mazda knows the car has this vibration issue. After testing/identifying FOUR units that all exhibit the vibration they could not cure it and have concluded it is “as designed”. Let me tell you, I have test driven almost all the CUVs out there and NONE vibrate like this. It is NOT normal!

    So, this car is my first and LAST Mazda… and they are NOT planning on fixing this so BEWARE!!
  • maavalousmaavalous Member Posts: 17
    Mazda still refuses to correct the vibration... I'll be pursuing other options for getting rid of this LEMON. :lemon:

    If you own a CX-7 AWD you may have this defect and not realize it... yet.
    The vibration is evident at all speeds over about 50mph but most evident at 65 to 75 mph. The kicker is, if you typically drive less than a couple hours non-stop you may not have experienced the true problem. Once the vehicle has been driven for several hours non-stop the vibration escalates dramatically until it is almost unbearable. As if you had a square tire.

    So, if you own an AWD and you sense any constant vibration on smooth roads at highway speeds, you have the issue. And, I'd like so ask for some help. I'd like you to reply to this post so I can determine if there are enough of us out there to qualify for a Class Action Suit. Mazda already admitted to finding one more like mine. Lawsuits are not fun, so hopefully, I can make Mazda aware of enough other cases that it will be an incentive to realize they can't ignore this issue. Ultimately, I will need to get your VIN# to prove to Mazda the cars exist... but that can come later. Right now, they are treating me like I don't exist.

    So, it appears they have me where they want me... they got my money and they are NOT going to fix the problem. A case of the big corporation showing what they really think of the customer.

    I am truly glad that Mazda does not make heart defibrillators!!
  • almattialmatti Member Posts: 164
    Maav; I have 2001 Pathfinder - 114k miles, it suddenly developed severe vibrations. Thought it was my son's fault _ hit some huge pothole - that wasn't the case. Rotated the 6 week old new tires, that wasn't it. Had it checked out at Nissan: Front Transfer Case and driveshaft with a U joint - slightly warped. CHECK THE TRANSFER CASE That could be a source of the problem IMO.
  • wwestwwest Member Posts: 10,706
    The CX-7 is a "base" FWD vehicle, sideways mounted engine, and therefore uses a PTO, Power Take-Off, rather than a transfer case. Front drive is pretty traditional, left and right halfshafts using CV joints. Directly driven rear driveline/shaft via the PTO with a dual electromagnetic clutch mounted integral to the rear diff'l for "controlled" engagement, up to half, of rear drive torque.

    Any vibration unique to the F/awd system would most likely involve the rear driveshaft and/or its U-joints.
  • almattialmatti Member Posts: 164
    wwest, maavoulous' CX-7 is AWD and does have a transfer case. On my Pathfinder, I just replaced the U joints on both drive shafts, the virbration is now WORSE than before. When the mechanic took off the front driveshaft and thus making the PF a rear wheel drive only vehicle, the virbration was 85% gone, still a small vibration sensed in the rear. I saw the one damaged U joint on the shaft, BUT he did say there is something not right in the front transfer case and thought there was a "noise". It was decided to replace the U joints fore and aft. Got it back yesterday, it's WORSE. Reason: there is a bad X-fer case gear and now that the driveshaft is re-connected to the transfer case with stable U joints, the vibration is being more firmly transmitted. I just spent $650 doing this. I should've known better: ANY VEHICLE with 114k miles , 8 years old, with bells & whistles like auto 4WD, will become a Money-pit.... What a mistake putting new tires, and new spark plugs a few months ago. Should have traded it in. Japanes cars or not that 100k miles is still a Magic Number.
  • maavalousmaavalous Member Posts: 17
    Sorry... you have been misinformed. The CX-7 is a F/AWD and virtually all F/AWD use a PTO and some form of controlled clutch in the rear differential. The Audi Quattro system is actually R/AWD and does have an xfer case (Torsen system is the BEST). But, to do that system you have to have a longitudinally mounted engine and most CUV go for latitude to conserve space.
    Your Pathfinder is actually a 4WD based on a truck design.
  • bigmick1bigmick1 Member Posts: 4
    I have a 2008 CX-7 AWD.

    In most respects I love the car. However, it has a FIERCE vibration between 50-63mph. Smooth as glass below 50. Over 65 a slight vibration that I can live with (after all it is a 4cyl turbo). The vibration was mild and barely noticeable when I bought the car (obviously or I wouldn't have purchased it); now it is truly teeth-rattling - especially under acceleration.

    When I first reported it, I was told it was because of how badly worn the OEM tires were after only 20,000mi (a whole other issue!) New tires, balancing, alignment, etc., still there. I have just now been told by the dealership that this is "normal" for this car. Bulls***. I am 45 (been driving for 29 years) had have had many cars, some turbo, some AWD. Never had a vibration like this (except, like another poster in a high mileage Pathfinder that had a transfer case going bad) - not even in this car when I bought it.

    I have less than 29K on my CX-7.
  • maavalousmaavalous Member Posts: 17
    There are a couple of things to check before you give up...
    Don't worry about driveshaft, if you had a bad one, it would have vibrated from start. A common problem. A quick check of the CV/U joints on the shaft (there's a dozen) is all that can be done there now.
    There is an issue with the rear wheel bearing and hub that you might check. Not common but possible.
    If you've done a force balance on tires and checked both tires/wheels for round... did you hit an open manhole lately?... then that's clear.
    Warped break rotors is a possibility... worth looking at.

    Otherwise... you may be in deep poo poo.
    Mazda is buying mine back because they couldn't fix it :(
  • bigmick1bigmick1 Member Posts: 4
    Well, here is the UPDATE:

    I just picked up my AWD CX-7 up from the dealership. After they told me the vibration was "normal" and "the same as in a new one off the lot," I took the service agent for a ride with me. He agreed that the vibration deserved a second look. Turns out the technician never actually road tested the car (as I specifically requested) but instead just ran it up on the lift (no load). After my complaint and ride-along with the service manager they ran it up on the lift again, but up to the equivalent of almost 90mph with no load - at which time the vibration manifested itself. Based on those observations they replaced the "Rear Propeller Shaft" which transfers power from the front diff to the rear diff and the flexible joint that connects it to the front. They had the car for nearly a week. Results: It's like Mazda gave me a new vehicle - in fact, I think it rides BETTER than when I first bought it. The transformation was not minimal - it is smooth as glass now; almost unbelievable given how bad the problem had gotten. The work was done under warranty, total cost to me: $0.

    I've only driven it about 100 miles since then, so I'm keeping my fingers crossed.

    Thanks for these forums for helping me to keep the pressure on.

  • maavalousmaavalous Member Posts: 17
    I'm a bit surprised... but happy for you :)
    My vibe only got slightly better when they replaced the driveshaft. That was a known problem and they did that to mine on first visit so your dealer tech didn't even go to the Mazda tech site to look or he would have checked that first. Keep an eye on those guys... they clearly aren't paying attention. No road test... geez!
    Just for clarity, there is no "front diff" or "rear diff" the way you may be thinking from truck-type systems. The front is a PTO (Power Take Off) unit and the rear is a limited slip differential with a magnetic clutch system that engages/disengages the drive shaft. The driveshaft spins 100% of the time, just doesn't provide torque until the magnets lock in (wheel slips somewhere).
    Good luck... they are great cars when they are working :)
  • wwestwwest Member Posts: 10,706
    With this type of F/awd(***), most of us know that the point at which power is taken off the "front" and routed to the rear driveline is actually, internally, from the front diff'l carrier itself or from the same point that drives the front diff'l carrier.

    And I don't know if the rear diff'l has a mechanical LSD or a virtual one via TCS using selective braking. Given the current trend toward simplicity and lowering the vehicle weight, I would guess a virtual one. In any case the rear differential carrier is driven by the duel electromagnetic/mechanical clutch assembly mounted integral to the rear diff'l case.

    The electromagnetic clutch design aspect allows a continuously variable coupling coefficient front to rear so the rear can be driven even if these is no front slippage.

    But like you, I would assume that the instant front slippage is detected the rear coupling coefficient becomes 100%. Obviously if wheel slippage isn't abated via that action TCS will just as instantly dethrottle the engine while simultaneously braking the slipping wheel(s), most likely the front slipping wheels.

    Given the fact that the PTO must be, is, continously cooled via the engine coolant flow I would guess that the F/R coupling coefficient is normally, straight line driving and no braking, something other than zero.

    *** Used on the Ford Escape, Mercury Mariner, Mazda Tribute, CX-7, and now the Toyota Venza and 2010 Lexus RX350. Likely also soon on the Highlander and Sienna. Also, Porsche has just adopted a clutch of this type for driving the front wheels of the 911 C4 model line.
  • jdorf40jdorf40 Member Posts: 1
    Man, I feel your pain. We've leased a 2008 CX-7 AWD Grand Touring. It's TERRIBLE. We've had success in the past with Mazda vehicles, but this thing is not a smooth ride, it burns thru tires like you're driving on lava, and in the snow it's borderline dangerous when you try to stop. There is serious vibration issue, but the tires are bald. We are going to be replacing them this weekend and I'm hoping that the vibration stops, otherwise I'm going to be an un-happy customer! Put me down if you're thinking civil because I'll sign.

    Justin :mad:
  • wwestwwest Member Posts: 10,706
    Add to my list should I purchase a 2010 CX-7.

    Add to the capability of the switch I already had in mind. I expected to add a switch in order to be able to manually put the system in "FULL-TIME" 4WD any time roadbed conditions warranted.

    "..burns thru tires.."

    A sure and certain sign that the rear driveline is being engaged improperly or with to great a coupling coefficient resulting in inappropriate level of tire scrubbing. I am noticing the same problem being posted for the RXh and HH.

    Now it looks as if that same switch should be used to disable 4WD otherwise.

    Or three switch functions, 4WD "OFF"/disabled, 4WD locked "on" FULL-TIME when adverse roadbed conditions are a certainty, and automatic 4WD enabled in rain or with OAT near or below freezing.

    My '01 F/awd RX300 came with the capability, C-best programming, to disable the A/C compressor functionality for an indefinite period, and second, to unlink the A/C from operating automatically in defrost/defog/demist mode. I NEVER allow the A/C to be used for any purpose but for cooling or initial cooldown of the cabin.

    Having the same feature on the CX-7 might move the preventative A/C compressor replacement requirement from 20-25,000 miles to double that.

    ' the snow..." "..borderline dangerous when you try to stop.."

    First, " the snow.."

    This implies that either VSC or ABS is TOO active in slippery roadbed conditions.

    I have two suggested fixes.

    1. Do NOT allow ABS activation UNLESS a stability control system indicates the need.

    2. In rain or with the OAT near or below freezing disable FRONT braking capability ENTIRELY for light to moderate braking absent "1", above.

    To continue:

    There should be NO 4WD coupling coefficient to the rear during braking or VSC/TC activation.

    The CX-7 uses, mistakenly IMMHO, some minor(??) level of drive coupling to the rear during low speed turns. Supposedly this is done in order to alleviate, at least partially alleviate, the propensity for loss of control when high drive torque AND lateral traction might result in loss of directional control. Helps, in addition, to the reduction of torque stearing effects.
  • wwestwwest Member Posts: 10,706
    "..vibration issue.." "..but the tires are bald..."

    In my opinion that is the condition in which vibration due to tire balance is most likely.
  • bigmick1bigmick1 Member Posts: 4
    My experience has been that the "burning thru tires" issue is more closely related to the quality of the OE tires than the possible driveline issues. After replacing my OE Bridgestones at (IMO) an unusually early mileage number, the Continentals I replaced them with have been wearing normally. I now have almost 15K on the new tires, 40K on the car. The wet/snow traction is much better, and the road noise is much reduced. With nearly 15K on the new tires I am comfortable saying that most of the traction/tire wear issues seem to be related to poor quality OE issued tires. Posts on other forums also seem to support this.

    The only issue I have had related to the 4WD driveline, is the vibration issue. That issue was completely solved at with a warranty replacement of the "rear propeller shaft." (quoted from service docs). The car ran smoother than new after that. However, it appears to be returning. I once again am starting to notice a slight vibration, under acceleration, between 50-60mph. Presumably this will worsen, as it did before, until another repair is warranted.

  • maavalousmaavalous Member Posts: 17
    Whew... I missed a few posts lately.

    1) Switch to over-ride the AWD and have it on command. Nissan has that as well a several others. But, it only works up to 15 mph for a long list of reasons. Without the clutches modulating the power to the rear, you'll burn up the system. If you know a way to add such a switch to a CX-7... you must be some extreme tech geek and I am not worthy!

    3) Turning off the A/C compressor on command??? Sorry, I'll file that under "silly mods for bored people". There's a button on the dash for that :)

    2) Most of the tire issues are just cheap OEM tires... my son-in-law worked for Goodyear. They definitely make "cheap" versions of their tires for the mfrs. to use. And, the mfrs. use the smooth and gripping tires for giving the car excellent off-the-lot ride/handling. Look at the Treadware rating on OEMs... you'll see numbers in the 200 range. Then, look at something like a Goodyear Assurance... over 400!!

    3) The propeller shaft (tail-shaft) replacement is a well-known fix for some units and some degree of vibration. If yours is returning, then one of two things... either they replaced with another bad one or you have the "real problem" with the CX-7 AWD system. And, there is no known cure... only lots of proof that it is real.

    4) On the issue of "should I get a 2010 CX-7?". MAN! I have just taken delivery on a 2010 GT with FRONT wheel drive. This car ROCKS in a ton of ways my 2008 did not. They made hundreds of small changes that, in my opinion, "finished" the car they started. With 2,000 miles on it, I love it!!

    That being said, note that I did NOT get AWD. Mazda could not assure me that they would make any changes and, if they did, it wouldn't be until the 2011/12 model range.

    Frankly, I'm going to have see written/public proof that Mazda redesigned their system or scraped it for a known reliable system from a 3rd party. Frankly, they couldn't fix it on a 2008... I have VERY low confidence they can fix their internally designed one ever :(
  • wwestwwest Member Posts: 10,706
    1. A couple of points.

    a. Engaging the rear drive full-time is not a problem if you drop one of the front halfshafts. ...CX-7 = RWD

    b. Having the rear drive fully engaged along with front drive is not a problem when driving on consistently slippery, low traction, surfaces.

    c. Having both front and rear drives engaged once underway, >20MPH, can be HAZARDOUS, as is ALWAYS the case for FWD. With both front and rear drivelines engaged simultaneously you increase the danger of plowing/understearing significantly, and ABS will basically be non-functional, as would be VSC, stability control.

    d. I guess I do quality as a "tech geek" as I would have no problem providing PWM modulation of the ATC.

    3 (??) No, that button on the dash does not typically prevent the A/C from operating, often with NO indication of same, in the windshield defrost/demist/defog modes, full or partial. And that's when use of the A/C is most problematic, DANGEROUS.

    And I find it much easier to turn the A/C off just once for the entire season rather than check to be sure it isn't enabled (someone/me having inadvertently used the "auto" PB). each time I start the vehicle.

    2. No. again. 244HP and "automatic" PART-TIME 4WD adds up, simply, to a LOT of tire scrubbing(tires, weakest "link"). Absent FWD biasing and 244HP, a lot of NEEDLESS tire scrubbing. Put that same 244HP, or even 600HP in a RWD or R/awd vehicle and the manufacturer no longer must protect me from myself.

    I'd much rather have a simple 2WD, even FWD, the majority of the time and be able to bring in the opposite driveline selectively, on my own, when the need arises. Not by any means saying the TC utilization of the rear drive capability isn't justified. But that REACTIVE use is unlikely to result in any significant level of driveline stress or tire scrubbing, if any at all.

    3. (The second 3). As has already been said the CX-7 uses 4WD pre-emptively, often engages the rear driveline only on the presumption of need. Not only does that result in a lot of needless tire scrubbing, tire scrubbing only on the POTENTIAL of need, but puts a LOT of needless stress throughout the entire driveline. Drive shaft U-joints and front and rear halfshaft CV joints (8 of those..??) come immediately to mind. 50,000 miles before one of those begins the failure process..??

    Oh, in my experience the drive shaft U-joints will be much more prone to failure than the CV joints.

    I can't help but wonder if detuning/derating of the engine HP/torque in the lower gear ranges might be a better overall solution.

    4. "Should I get a 2010 CX-7?" Shamefully the new small I4 is not available with the F/awd system. So if you want/need F/awd the 244HP turbo I4 is "it." $5,000 extra just to get the automatic climate control, the only part of the option package that has appeal for me. NOT..!!

    I would normally be reluctant to advise the kind of modifications I might do to make it more safe and functional but I just "stumbled" across something called "the brown wire mod" for the Ford Explorer. Apparenty it is a way to disable the "R/awd" mode. I don't think this category of a modification would be as common for a base RWD such as the Explorer, but here it "was", post #59.

    Or Google search"

    "brown wire" ford explorer.
  • wwestwwest Member Posts: 10,706
    A shame, really a shame.

    Had you known of the "brown wire mod" YESTERDAY, you could have gone ahead and purchased the F/awd CX-7 without having to wait for Mazda's "improvement."

    By the way, the new Venza and 2010 RX350 both use the CX-7's F/awd system virtually exactingly. The only exception I see is the lack of PTO cooling that the CX-7 has already. Obviously that might protend a less functional, or less "used" F/awd system as Ford has done with the Escape once they discovered the short-comings in the base design.

    Wonder how easy it will be for Lexus to add the PTO cooling..??
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