I had this same problem with my 2007 MS6. It occurs with a quick throttle/load application, but I could not make it go away even with 110 octane race unleaded. I then had the dealer do the reflash thinking it would fix the problem, but no luck. It took 2-3 visits with the dealer for them to even duplicate the problem. Finally, they determined that the driveshaft (from front to rear diff) had a bad mount and was vibrating under load. The vibration supposedly effected a sensor in the 4WD system, which fooled it into thinking there was rear wheel slippage, which in turn triggered cutting the throttle. I sort of made sense, so I didn't argue since the dealer was very easy to work with. The axle was back ordered for a month, so they pulled one from a new MS6 on the lot! Funny thing is that after a week or two, the car is starting to do the old "knock", with simultaneous, momentary sudden power drop. It's not as bad as before, but I'm getting frustrated. Maybe time for a 2008 vette !


Tom

 

I have the complete service and repair manuel from the dealership if you need a copy I can email , its on a PDF file.

-Allan

 

dont use octane booster on boosted cars or trucks.........its screws up the O2 sensors and inturn the ECU's ability to get ur Air/Fuel ratio right.

now this knocking ur hearing...........take a empty can of pepsi(or soda of ur choice) put some marbles in it or some BB's from a bb gun.........shake the can..........does the sound of ur car sound like that? if it does ur experincing DETO........which can be caused by too advanced timing, or a lean condition. Either or Deto is bad. usually the end result in contiuous deto is a new motor if not remeided.

if not............take a metal rod of some sort.......screwdriver or whatever.........and tap it quickly up against valve cover or something solid on ur motor(dont bang it too hard just enough to make solid contact and a solid noise).....now does it sound like that? if it does u may have a ringland going bad, or maybe a valve seat giving out on u. Or it can be spark knock.......which is probably something that all speed6's will encouter from time to time due to the top mount intercooler. Usually the people at the specific Mazda dealers dont know much about the cars they work on......they lok at a book that tells them "hey if this is happening its this this or this" and ETC.

pull ur plugs and come back and describe what they look like to me.

how often do u check ur oil? Mazda's eat oil for some reason........and ur boosted so oil life is very important to u. My haed went on my 3.0L .............head was starved for oil......TICK TICK TICK........mazda come get ur car.............lol........i knew what it was but it was under warranty so im not gonna touch it.

get back to me.........we need to get ur problem solved!

AGAIN! if boosted............dont use octane booster.....if u want better fuel pay for it and get the real stuff!

 

u wouldnt happen to have one for the regular 6(3.0L) would u? could u email me the one u have for the Speed6............

ive been working on something with the 2 and that manual would be of great help to me.

justinw@twistedvisionz-carclub.com

appreciate it

 

Thanks for the good thoughts. I have never used octane boost for the obvious reasons. Not a good idea.

Also thanks for the offer of the manual pdf. No need for it now though.

When the knocking occurs, it is accompanied by an abrupt but short lived loss of power. I still maintain that it is detonation that the knock sensor/computer is unable to adjust timing, fuel curves, and electronic throttle quickly enough for. The dealer said it was not detonation, but was the driveshaft/mount. I'm still not convinced, but they didn't see any detonation or knock sensor codes when they rode with me using a laptop connected to the car.

You mentioned spark noise, but this car has individual coils at each plug, ie. no plug wires to arc, etc. That wouldn't make a loud rattling noise with a big sudden power drop, maybe a missfire.

I may leave the car with the dealer again, but I'm going to turn it in soon since it's leased (miles racking up!) It really is a cool car, but with some minor flaws.

I still have another Mazda - my RX3 race car to keep me busy.

Cheers,
Tom

 

When the individual coils go bad, you end up with a serious mis-fire condition (vehicle bucks real bad.) I had this occur on an 01 F-150 I had. And once they go bad, they're bad. They don't tend to fail intermittently.

 

OK, so I'm not the only one with this problem. I'm glad. =D

Yes, I think that the bad driveshaft thing is unlikely... but perhaps it is true and some design flaw keeps messing them up. Anyways, I've had the same problem since my car hit about 2500 miles. Its now got about 15,000.

My extent of car knowledge is 'Oh, I think that's where the dipstick is to check the oil... maybe I should do that once a month or something like that'. All I know is all my 'die-hard car tweaking' friends have no solid idea what it is... and the dealership keeps shipping it back to me.

Basically, I have the exact same symptoms - generally around 3k RPM, but not always (I've had in the 2ks all the way through the high 4ks). I drive mine hard, all the time, so it happens fairly frequently. They seem to think it may be related to waste gate on the turbo (like I know what that is). They've kept it for week + driven it hundreds of miles and never get it to duplicate. I got it to duplicate once when the tech was in the car with me - but only once. Pisses me off really really bad, but what can you do?

They keep saying that they can't run it with the machine hooked up without a 4 wheel dyno because its illegal to drive with the computer thing hooked up that monitors everything. And they can't get any type of code, etc. because the central computer doesn't record any problems. Auuuugh. I tracked it for a whole month this spring to see if I could find patterns and realy nothing... almost all gears (2nd-6th), wide range of RPMs (2400-4800), and range of length of time running (<1 minute - >4 hours), and decent range of temperatures (68-91) [I'm in AZ so, yes, 91 degrees is a spring temperature, lol]. It seemed to happen less in the middle of the summer but that could be related to my lethargy and realization that the turbo doesn't do much when its 115+. (we had 38 days over 115 this summer, so that's 38 days of sucky performance, lol)

All I know is I've pretty much decided to trade it in and get a new car before it goes out of warranty (40k on the '06 speeds). Any further updates as to what happened to you?

Oh, and P.S.... do you think those two recalls they just sent out may fix this?

 

I have this noise as well on mine and was just looking it up to see if anyone else heard this. Mine sounds like a can of rocks when you acclerate in to low of a gear.. only happens sometimes. I heard it for the first time the other day, but my husband has heard it a few times I guess. I sent him this information for him and have him check it out...