Stuttering issue!! Gearbox/torque convertor or engine miss? Please help

[BmwBrian]

ive spent hours of research on this and here is something i stumbled on the other day.
before i go into that id like to say i have unplugged my maf and also cleaned it and same issue...
i have also put it into steptronic mode to find its not as noticable but after a while it stutters again!

here is the head scratcher...
so we all know fuel air and spark makes pistons and engines fire.
so i tried cheap gas and yes i had alot more stuttering and rpm jumps.
this now makes me wonder if my coil packs are just not as sparky.

other than that my transmission also shows no sign of gear issues.
and if its the tranny im sure its the valve body.
these trannys are infamous for valve body issues where the dealer will burn you and swap the whole thing this coming from my long time bmw mechanic buddy who quit being a mechanic but has all his m cards and german training 13 year bmw mechanic back in boston im in fl now so i cant use him...

so valve body / filter / gasket / fluid
about 600.00 do it yourself in an hour and there is a great video on you tube.
also if you drain your tranny ive heard thru the grape vine you should not drain it completely that the aluminum that has disolved into fluid creates a bond between your gear rings thats why bmw says dont change your fluid.
just change whats in the pan.

this is a head scratcher and in a few weeks my car will go into dealership i have an 03 4.4 and i know there are 2 tranny updates i need ill repost what the dealer diagnoses.

i was positive it was the valve body but after the cheap gas technic im wondering if it is intake cam sensor / coil packs.

i have a new fuel filter so i know fuel is getting there clean, new plugs also injectors have been cleaned and tested. its either air or spark and im betting spark. although that would show a misfire code pretty quickly...again stumped!
any input would be great. sorry for the long post.
130k on it btw

[amacman]

I wonder if high ethanol content in fuel can cause this .
The ecu mapping on these things vary modes depending on throttle position / engine load and all sorts .

[bbultman]

I've talked pretty extensively with engineers at ZF and weak coil packs can produce a similar effect, especially if there's some load on the engine. However, in cruise control and Sport mode the throttle does not miss a beat. So it's hard to see the coil pack thing. Let us know what you find with the software. My X5 is getting ready for a new trans at 143k. Same thing though, my trans feels great - hard to justify. I know my TC is going and might as well do the trans while it's out. Out of warranty obviously so no stealership work.

[Sundayjumper]

Mine - 2001 4.4i w/ 117k miles - has exactly the same symptoms but doesn't seem to have got worse in the time I've had it. I'm building up to dropping the gearbox and changing the torque converter as I'm sure that's the problem.

[Livefreeordie]

Quick update, i done a simple atf fluid change and added the dr tranny. It shifts a lot more smoothly now and it has shuddered at all yet! I will keep you updated.

However, i have a new problem that the heater/blower fuse keeps blowing! Its a 7.5amp fuse. I tried as big as 15a but it still blows! Were should i begin?

I also have a hellish ticking/knocking/rattling noise of the engine which is really worrying me! It doesnt go away and gets quicker with higher revs??

Any. Help is welcome

[Livefreeordie]

Quick update, i done a simple atf fluid change and added the dr tranny. It shifts a lot more smoothly now and it has shuddered at all yet! I will keep you updated.

However, i have a new problem that the heater/blower fuse keeps blowing! Its a 7.5amp fuse. I tried as big as 15a but it still blows! Were should i begin?

I also have a hellish ticking/knocking/rattling noise of the engine which is really worrying me! It doesnt go away and gets quicker with higher revs??

Any. Help is welcome

[02x592]

Here's an update on my shuddering issue. Knowing full well the failing torque converter would take out the transmission as it spewed debris through the system I let it go too long anyways, and take out the transmission it done did. On the way home from work it started shuddering worse than normal and taking off from a stop light I hit the gas and the engine raced to almost redline then BAM the transmission engaged and produced a violent 4-wheel drive burnout. I was able to limp it home with what I thought was the torque converter completely gone. It drove fine in gears 2-5 but first wasn't having it. A few days later I got a call from the transmission shop saying my transmission needed to be rebuilt as they had done very specific tests, so I did let them tear it apart but didn't authorize any work until I had seen and verified it myself. I was not about to be the ignorant customer that gets hosed as $1k is far less than $5k. They weren't kidding! My fluid was burned and the pan was full of shavings plus the valve body was full as well. A few burned clutch packs and a hardly working torque converter are what I ended up with. Got the truck back today and all is well again.

[BmwBrian]

My car is in shop now and I can tell shaving have been splattered all over my tranny but I'm only flushing fluid in pan and filter and changing the fluid in the pan to fresh fluid. Just to bandwidth it for abit longer.

I'm still curious about this future rebuild of mine!

[HPIA4v2]

Originally Posted by 02x592

Here's an update on my shuddering issue. Knowing full well the failing torque converter would take out the transmission as it spewed debris through the system I let it go too long anyways, and take out the transmission it done did. On the way home from work it started shuddering worse than normal and taking off from a stop light I hit the gas and the engine raced to almost redline then BAM the transmission engaged and produced a violent 4-wheel drive burnout. I was able to limp it home with what I thought was the torque converter completely gone. It drove fine in gears 2-5 but first wasn't having it. A few days later I got a call from the transmission shop saying my transmission needed to be rebuilt as they had done very specific tests, so I did let them tear it apart but didn't authorize any work until I had seen and verified it myself. I was not about to be the ignorant customer that gets hosed as $1k is far less than $5k. They weren't kidding! My fluid was burned and the pan was full of shavings plus the valve body was full as well. A few burned clutch packs and a hardly working torque converter are what I ended up with. Got the truck back today and all is well again.

Just wonder how much was the total cost?
Is it BMW indy shop, tranny shop?
TIA

[Big "J"]

Originally Posted by 02x592

Here's an update on my shuddering issue. Knowing full well the failing torque converter would take out the transmission as it spewed debris through the system I let it go too long anyways, and take out the transmission it done did. On the way home from work it started shuddering worse than normal and taking off from a stop light I hit the gas and the engine raced to almost redline then BAM the transmission engaged and produced a violent 4-wheel drive burnout. I was able to limp it home with what I thought was the torque converter completely gone. It drove fine in gears 2-5 but first wasn't having it. A few days later I got a call from the transmission shop saying my transmission needed to be rebuilt as they had done very specific tests, so I did let them tear it apart but didn't authorize any work until I had seen and verified it myself. I was not about to be the ignorant customer that gets hosed as $1k is far less than $5k. They weren't kidding! My fluid was burned and the pan was full of shavings plus the valve body was full as well. A few burned clutch packs and a hardly working torque converter are what I ended up with. Got the truck back today and all is well again.

So, do you think if you would have changed the tranny fluid at the first signs of the shuddering it would have helped or delay the inevitable?