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Please help! :(
The past couple months have been a bit of hell with my car.
I have an 05 645 SMG. I'm not the saviest when it comes to car mechanics so please excuse the noob-ness in describing my issue here:

Currently, from dead stop, i put the car in gear and accelerate but the car barely moves, as if it has no power, but the RPMs shoot up. After enough tries of accelerating or holding it long enough, it feels like the transmission "engages" and the car will jerk, tires skip (similar as if I was peeling out). Immediately after it seems that the tranny stays engaged bc I can resume driving (somewhat). Shifting to 2nd is a similar issue but I guess since the car is already in motion, it's easier for the tranny to get into 2nd?

There are times while cruising, shifting into the higher gears (3rd - 6th), you can feel the same issue occur. I'll shift and you feel the car lose power and the RPMs will subsequently drop to below 1000s, until I accelerate and it will magically engage again (with a little jerk thrown in).

After about 40 - 60 min of driving shifting into gear becomes a bit easier.

History of recent repairs: Done by my local Indie (reliable and has a lot of good reviews in Pompano Beach, FL
Nov - Replaced Hydraulic pump - $1.3k - (coolant flood prompted this repair, it was squeaking prior to this), belt, thermostat.
-During this time, the tranny slipping was starting to occur, maybe one every 2 weeks.
Dec - Replaced Alternator, - $1k - electronic modules were throwing all sorts of faults. Speakers were cutting out randomly, lights were randomly dimming. At one point the car went into a failsafe mode where I could only drive in 1st and 3rd gear. I understand the alternator had low voltage and the car's computer tells them to shutdown before they are damaged.
-During this time, the tranny slipping became more prevalent, went from once a week to maybe every other day.
-After replacing the alternator, the slipping occurred two days later, my Indie told me I had to take it to BMW to have the computer tranny reprogrammed bc they couldnt do it (something about BMW locking down that portion of the computer).

Last week, took it in to BMW, they performed clutch slip calibration $130. They told me if that didn't fix it, then I would need to replace clutch and flywheel, if I remember correctly that was in the $2k - $3k range. According to them, the previous owner replaced clutch but not flywheel and never had the tranny reprogrammed. Afterwards, the car drove beautifully! For about a week.
Now I'm back to the same slipping.

I'm a little concerned, although I'm no mechanic, why would the car drive correct after a computer programming has been altered, but only last for a few days? I would assume if the clutch is bad then the clutch is bad, no? Could the computer have a memory problem? :dunno::dunno:

If you made it here, thanks for reading through my nightmare!
Does anyone have any other suggestions? Details I may be missing that you might need for a better understanding of the issue? I've read through a good amount of the transmission forums up here that had similar descriptions as to mine, but dont think I found one that had same issue as mine.

Again I thank all of you for any advice given (and your patience)!
 

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Please help! :(
The past couple months have been a bit of hell with my car.
I have an 05 645 SMG. I'm not the saviest when it comes to car mechanics so please excuse the noob-ness in describing my issue here:

Currently, from dead stop, i put the car in gear and accelerate but the car barely moves, as if it has no power, but the RPMs shoot up. After enough tries of accelerating or holding it long enough, it feels like the transmission "engages" and the car will jerk, tires skip (similar as if I was peeling out). Immediately after it seems that the tranny stays engaged bc I can resume driving (somewhat). Shifting to 2nd is a similar issue but I guess since the car is already in motion, it's easier for the tranny to get into 2nd?

There are times while cruising, shifting into the higher gears (3rd - 6th), you can feel the same issue occur. I'll shift and you feel the car lose power and the RPMs will subsequently drop to below 1000s, until I accelerate and it will magically engage again (with a little jerk thrown in).

After about 40 - 60 min of driving shifting into gear becomes a bit easier.

History of recent repairs: Done by my local Indie (reliable and has a lot of good reviews in Pompano Beach, FL
Nov - Replaced Hydraulic pump - $1.3k - (coolant flood prompted this repair, it was squeaking prior to this), belt, thermostat.
-During this time, the tranny slipping was starting to occur, maybe one every 2 weeks.
Dec - Replaced Alternator, - $1k - electronic modules were throwing all sorts of faults. Speakers were cutting out randomly, lights were randomly dimming. At one point the car went into a failsafe mode where I could only drive in 1st and 3rd gear. I understand the alternator had low voltage and the car's computer tells them to shutdown before they are damaged.
-During this time, the tranny slipping became more prevalent, went from once a week to maybe every other day.
-After replacing the alternator, the slipping occurred two days later, my Indie told me I had to take it to BMW to have the computer tranny reprogrammed bc they couldnt do it (something about BMW locking down that portion of the computer).

Last week, took it in to BMW, they performed clutch slip calibration $130. They told me if that didn't fix it, then I would need to replace clutch and flywheel, if I remember correctly that was in the $2k - $3k range. According to them, the previous owner replaced clutch but not flywheel and never had the tranny reprogrammed. Afterwards, the car drove beautifully! For about a week.
Now I'm back to the same slipping.

I'm a little concerned, although I'm no mechanic, why would the car drive correct after a computer programming has been altered, but only last for a few days? I would assume if the clutch is bad then the clutch is bad, no? Could the computer have a memory problem? :dunno::dunno:

If you made it here, thanks for reading through my nightmare!
Does anyone have any other suggestions? Details I may be missing that you might need for a better understanding of the issue? I've read through a good amount of the transmission forums up here that had similar descriptions as to mine, but dont think I found one that had same issue as mine.

Again I thank all of you for any advice given (and your patience)!
I do not know much about SMG, but it sounds more like a clutch problem. I think it has 2 clutches? The programming sounds like BS, but anything is possible. Yorgi could probably point you in the right direction.
 
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