They all do that

#1

I have a 2008 MX-5 Miata with 300 miles on it. When I back out of the garage or a parking space and put it into drive (automatic transmission) is makes a “thunk”. That is the only time I hear the noise and it drives fine. I called the dealer and they said “they all do that”. He also said that when they do the computer updates at the first service visit that might help the problem. I know nothing about cars but if there is a problem with the transmission I don’t see how updating the computer helps. Does this make sense to anyone else?

#2

Oh, ye of little faith (in your dealer). Your dealer may be telling truth about the affect of the computer update (if there is one). You don’t have to wait until a service date. The car has a problem which should be covered under warranty, and you can have the dealer repair it at anytime. (Save yourself money by having your periodic services performed at an independent shop).

#3

I already have an appointment to have them check it (and to be fair, they immediately suggested I bring it in if I am concerned). I just wondered about the “they all do that” part of it.

#4

Are you stopping the car before you shift from reverse to drive? If the car is still moving backwards when you shift into drive, that is bad, and it might be causing this.

#5

Yes, I am stopping the car before shifting. That was a bad habit I had with my last car and I am being especially careful not to do it with this one.

#6

While you’re at the dealer tell them you’re going up front to the sales dept. and test a few other models on the lot to see if they all do that.
When you call the dealer service dept. on the phone you’re talking to a service manager or service writer; the vast majority of them having little or no mechanical expertise at all.
The correct answer would be to tell you to bring the car in and get it looked at.

While an '08 should not have a serious problem there is always the possibility of a production glitch, bolt left loose somewhere, etc.
Some possible causes of a thunk noise (assuming it’s not a transmission internal part) could be a loose/broken engine or transmission mount, driveline fault, idle speed too high, etc. Hope that helps.

#7

I just wondered about the “they all do that” part of it.

Easy answer to that one. Have them show you a new car on the lot that does it.

#8

A loose transmission mount was one of the things I thought of. they are being quite responsive so I am not anticipating a big hassle from them. I like the idea of driving another one to see if it makes the same noise. I have an appointment next week so we will see what they say. Thanks.

#9

I agree that an update to the computer might help the problem, but then again, this could be part of the usual service department mantra of “they all do that”. As was suggested, comparing your car to other comparable new ones will reveal the truth or the fallacy of “they all do that”.

Many years ago, one of my ongoing gripes with a brand-new Chevy was that the door lock button on the passenger door constantly rattled as I drove. On my second or third visit to the dealership to have this remedied, the new service writer told me, “Oh, they are supposed to be like that”. My reply was, “Well, I certainly want everything on my car to work exactly as it is supposed to, so when I come back to pick it up, please be sure that the lock button on the driver’s door rattles just like the other one”.

Yes, I was taking somewhat of a risk with my statement, but knowing that it was probably more difficult to make the good one rattle than it was to correct the problem with the bad one, I pretty much called this dullard’s bluff–and, guess what–when I picked up the car, the loose, rattling door lock button on the passenger door had finally been fixed.

Sometimes you just have to outwit these service writers at their own game, and since many of them come to a battle of the wits only half-equipped, it can be fairly easy to out-wit them. Give them a chance to re-flash the computer, and also test-drive one or two comparable Miatas. If the re-flash does not help, and if it seems like yours is the only one that is exhibiting this behavior, be politely persistent until you are satisfied, and “kick it up” to the corporate level if necessary.

#10

Thanks for the support. with any luck they will a computer update will help or they will find something else to fix the problem. I really like the car and have had a good experience with the dealership so far. I’m hoping they don’t blow it.

#11

One easy thing you could do yourself would be to check the idle speed. Raise the hood and there should be an underhood sticker with the idle speed listed.
Make sure the idle speed on the tach is at or very close to what is stated on the sticker.

If the tach reading is 50-100 RPM higher this could cause a thunk when shifting.

#12

I didn’t see a sticker with the idle speed listed.

#13

Christine, Welcome to Miatadom. My first thought when I read you post was u-joints on the drive shaft. Just my guess.

If you have not been to the Miata.net stop by and have a look. It is the place on the net for all things Miata.

http://www.miata.net/

It may be the ABS from a topic i just found on the Miata.net:

http://forum.miata.net/vb/showthread.php?t=289759&highlight=clunk

#14

Thanks. I thought about the u-joints but I would have never thought about the ABS. It happens every time I go from park to drive - not just when it has been sitting for a few hours so I am not sure that is it. Guess we will see what the dealer says.

#15

While a “thunk” does not really describe an ABS “self-test”, I suppose that this could be the cause of the symptom. On most cars with which I am familiar, every time that you start the engine and engage “Drive”, the ABS self-test takes place after driving a couple of feet.

#16

Well, that is when it happens - after I have put it into drive and driven a few feet. Since the Miata is so small I suppose it’s possible that it is the ABS. I can’t believe how many suggestions I have had. I will definitely share with everyone what it is - assuming the dealer can figure it out.

#17

Well, now that you are describing the symptoms more clearly, it really does sound like the ABS self-test is what you are hearing. I have to assume that the car that you had prior to the Miata did not have ABS, or that it was one that did not do a self-test each time that you start the car.

I am more sure than I was previously that you are experiencing something that it absolutely normal for the Miata, as well as for many other makes and models.

#18

I had a Mercedes SLK Kompressor previously. It definitely had ABS and I never heard a noise like this. However, I hope you are correct and this is absolutely normal for this car. I should note that prior to the Mercedes I had a Miata and I don’t remember hearing a noise like this on that car either.

#19

I hate ABS - I wish the manufacturers would get rid of it. It’s sooo expensive to fix, and I find no advantage to it as long as you have good driving skills. I had a pickup that had it and I found no use for it. Unfortunately, here you must keep your ABS working to get your car safety approved, even if the brakes are fine.

#20

most cars do have a self test for the ABS pump and solenoid systems, but usually you may just hear a click upon starting each time. These ABS pumps and distribution solenoids and high pressures and separate resevoirs for fluid are VER"Y expensive. and maybe this is the characteristic of the Mazda. A pressure test and proper initiation and sensing of the ABS system is easily tested, but you need special tools and knowledge.