shift shock: is it a bad design issue? - Mazda 6 Forums : Mazda 6 / Mazda Atenza Forum

funes · 10-05-2009, 09:57 PM

I had a number of problems: shift-shock in lower gears, especially 1>>2, gear shift; hesitation from a start and then shift shock, as though the car was hit from behind. Hesitation, bucking/surging problem at 40-70 mpr. Diagnosed my CEL with P0300 multiple misfire. After changing all the plugs and ignition coils, in higher gears and on the highway the car drives like new. But I still sometimes detect that notorious first to second hesitation and then a shift shock. So what is going on here? How does one resolve this issue? After seeing hundreds of shift-shock cases with M6 I am starting to believe that there is an underlying design fault somewhere. Has anyone actually permanently resolved this situation?

DRB94 · 10-06-2009, 10:07 PM

What year car is it and I am assuming its an automatic transmission. I had similar problems with my 06 6S but it was a tranny issue that got replaced by Mazda. Could be an idea if its not related to the misfiring.

funes · 10-06-2009, 10:21 PM

QUOTE (DRB94 @ Oct 6 2009, 07:07 PM)

Quote:

What year car is it and I am assuming its an automatic transmission. I had similar problems with my 06 6S but it was a tranny issue that got replaced by Mazda. Could be an idea if its not related to the misfiring.[/b]

Lucky for you the car was still under warranty. Mine is a 2003 ATX V6, so no warranty and thus replacing the transmission is really out of the question for me :--) . I would hope it's not the transmission, and probably not since it's fine in higher gears. I just get that hesitation from the stop but the funny thing is that the rpm is fine, it goes all the way to 4000 rpm before shifting into second ( but sometimes it functions normally). The strange this is that the rpm needle goes high up but the car barely moves, and after a few seconds shift into second and then everything is fine. Could it be a dirty TB? But why then does the rpm work fine? Doesn't TB control rpm? Man is it confusing!

kpjimmy · 10-07-2009, 10:20 AM

QUOTE (funes funes @ Oct 6 2009, 09:21 PM)

Quote:

Lucky for you the car was still under warranty. Mine is a 2003 ATX V6, so no warranty and thus replacing the transmission is really out of the question for me :--) . I would hope it's not the transmission, and probably not since it's fine in higher gears. I just get that hesitation from the stop but the funny thing is that the rpm is fine, it goes all the way to 4000 rpm before shifting into second ( but sometimes it functions normally). The strange this is that the rpm needle goes high up but the car barely moves, and after a few seconds shift into second and then everything is fine. Could it be a dirty TB? But why then does the rpm work fine? Doesn't TB control rpm? Man is it confusing![/b]

Either a bad TB or a dirty one. Its an easy thing to clean if you have the time. The only part is that its recommended to wait like 4 hours before removing the TB and the antifreeze hoses that are connected on the TB. That thing gets HOT.

I have had shift shock but has pretty much gone away for the most part. With my replacing of the TB with an Optimized one and installing a wishbone CPE mount it doesn't happen as frequent as it used to when it was stock. Others have said to install a tranny cooler on as well helps.

Oh and another thing, being that we have an 03 as well, when was the last time you had your ECU flashed? I know mine was flashed at least twice. I think the last one was the MSP10. Also there is a technical service bulletin that is out for our years for high revs as well, but I am not sure if its "cured" by the latest ECU flash.

GL!

funes · 10-07-2009, 08:43 PM

I have suspected the TB for a while now but the first thing I'll do is to flash the ECU/TCU and see what happens; I suspect it has never been flashed since everything from the first owner was stock, including spark plugs and coils (it has 93k miles now).

I heard good things about the tranny cooler too but I don't notice any dependence on engine temperature or air temperature on the hesitation in first gear; probly won't help in my case. Was also thinking of possible vacuum leak somewhere, but in that case one would expect poor performance in higher gears, but thats not the case. And the same goes for a bad TB: it should negatively affect performance in higher gears ( I would think). So gonna flash the ECU first and take it from there. I 'll make sure to leave an update here for anybody else who is having the same issues.

10-06-2009, 10:07 PM	#2 (permalink)
DRB94 Learners License Join Date: Aug 2008 Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts Groans: 0 Groaned at 0 Times in 0 Posts iTrader: 0 reviews	What year car is it and I am assuming its an automatic transmission. I had similar problems with my 06 6S but it was a tranny issue that got replaced by Mazda. Could be an idea if its not related to the misfiring. __________________ Tungsten Gray 06 6S Grand Touring, Mazdaspeed CAI, Steeda TB Spacer and grounded TB,TB coolant bypass. 6spd ATX.......Wanting more n more n more Official Honda Hater

10-05-2009, 09:57 PM	#1 (permalink)
funes Drivers License Join Date: Sep 2009 Location: Brooklyn Posts: 78 Thanks: 0 Thanked 0 Times in 0 Posts Groans: 0 Groaned at 6 Times in 6 Posts iTrader: 0 reviews	I had a number of problems: shift-shock in lower gears, especially 1>>2, gear shift; hesitation from a start and then shift shock, as though the car was hit from behind. Hesitation, bucking/surging problem at 40-70 mpr. Diagnosed my CEL with P0300 multiple misfire. After changing all the plugs and ignition coils, in higher gears and on the highway the car drives like new. But I still sometimes detect that notorious first to second hesitation and then a shift shock. So what is going on here? How does one resolve this issue? After seeing hundreds of shift-shock cases with M6 I am starting to believe that there is an underlying design fault somewhere. Has anyone actually permanently resolved this situation?

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10-07-2009, 08:43 PM	#5 (permalink)
funes Drivers License Join Date: Sep 2009 Location: Brooklyn Posts: 78 Thanks: 0 Thanked 0 Times in 0 Posts Groans: 0 Groaned at 6 Times in 6 Posts iTrader: 0 reviews	I have suspected the TB for a while now but the first thing I'll do is to flash the ECU/TCU and see what happens; I suspect it has never been flashed since everything from the first owner was stock, including spark plugs and coils (it has 93k miles now). I heard good things about the tranny cooler too but I don't notice any dependence on engine temperature or air temperature on the hesitation in first gear; probly won't help in my case. Was also thinking of possible vacuum leak somewhere, but in that case one would expect poor performance in higher gears, but thats not the case. And the same goes for a bad TB: it should negatively affect performance in higher gears ( I would think). So gonna flash the ECU first and take it from there. I 'll make sure to leave an update here for anybody else who is having the same issues.