Acceleration issue

[WHM3]

Hi all. I'm new here. A few months ago, I took delivery of a new-to-me 2008 E93. It replaced my beloved E36 M3C.

I'll be taking it into the dealer for this as well as a very annoying acceleration issue, which I need to see if others on this forum have experienced.

While I love this car, I'm second guessing myself for buying it used. My E36 was purchased new (and at the end of the model run) so it was darn near perfect (they had 7 years to work out issues).

I'm looking forward to learning a lot from you all!

[SlammedR8]

welcome to the forum,

what sort of acceleration issue are you experiencing??

[WHM3]

Originally Posted by slammedm3

what sort of acceleration issue are you experiencing??

I don't want to hijack this thread, but you did ask. If we need to, can this part of the thread be moved into a new thread?

On a cold start and while slowly accelerating (say, down my cul-de-sac or out of my office park), the car will "buck" (it's a pretty severe and violent forward/reverse shake of the entire car) a few times starting at 2700rpm through about 3k rpm. It happens pretty regularly, although it's not 100% reproducible.

I took it to the dealer once, left it overnight, and they couldn't reproduce the issue the next morning. They analyzed the gas and said it had 13% ethanol which they think may contribute to the issue. I don't buy that as I only put in premium brand gasoline (ExxonMobil, Shell, etc). They also reset the "adaptation values" since the car was new-to-me. For a few days, it helped mitigate the issue. Starts were much faster and the shake was reduce tremendously (although not 100% fixed). But, the problems quickly returned.

I found that if I rev the engine past 3K before I take off, the problem tends to not manifest itself. But, I've also had this type of issue when I'm trying to accelerate somewhat quickly (say, trying to turn into cross traffic). I think these 2 events are related.

And, I also found that when the car begins to "buck", if I step on the clutch (I have a 6MT), the car immediately stops shaking. *Usually*, the problem is solved for that driving session, but I've had it immediately happen again 1-2 more times.

Needless to say, this is an extremely annoying issue. While I have a workaround (revving the engine), I don't think I should have to do this. I'm going to keep making appointments, leaving the car overnight, and then going there first thing in the morning so that I can drive the car with a SA or a tech until one of them sees the problem first hand.

Between these issues and my leaks...I'm really not enjoying this car as much as I should be.

[foosh]

Are you saying you only experience these symptoms immediately after a cold start? What is your experience level on manual transmissions?

[WHM3]

Originally Posted by foosh

Are you saying you only experience these symptoms from a cold start? What is your experience level on manual transmissions?

Yes, it only happens on a cold start. And, the temps don't necessarily need to be very cold (although the colder it is, the more likely it will happen).

I've been driving a manual for the past 10 years with my E36 M3, and then a few years with a 325i before that, although I did take a good 6 years off when I was driving my Chevy.

You don't even need to shift. Put the car into first, slowly accelerate to 2700 and enjoy the shake.

[foosh]

Well, this is pretty normal on many manuals when cold. I see it on my E93 M3 for maybe 2 minutes after a cold start, and get around it by modulating clutch and throttle, as you seem to have learned. I've experienced it on many other manuals as well, including my RS4. The reason the dealer couldn't find it was they likely thought it was normal and didn't notice it while using the right technique, or they warmed the car up for more than 2 minutes before driving it.

This engine is not a torque monster down low, as opposed to something like the LS7 in a Z06, which would pull in 4th gear at 2K rpms from a standing start. When cold, it will balk even more without a few more revs.

Bottom line is, I don't think you have a problem. If you think that 2 minute inconvenience is a major problem, I'd be worried about you.

[WHM3]

Originally Posted by foosh

The reason the dealer couldn't find it was they likely thought it was normal and didn't notice it while using the right technique, or they warmed the car up for more than 2 minutes before driving it.

It is possible they let the engine warm up enough to overcome the issue. This is why I'm going to drive with a SA or tech the next time I take it in. But, when the problem happens, I guarantee you no one would think it's normal.

Originally Posted by foosh

will balk even more without a few more revs. Bottom line is, I don't think you have a problem. If you think that 2 minute inconvenience is a major problem, I'd be worried about you.

I'm surprised you think it's normal for a car to violently shake. We're not talking about a shake like a bent rim. We're talking the entire car is shaking almost to the point where you're being jolted out of your seat and the seatbelt is tightening to keep you safe. This is NOT normal for any car.

Seeing how you haven't seen how my car behaves, it's possible that we're talking about 2 different things.

If this were truly an issue that "many or most" cars with manual transmissions have, then resetting the adaptation values should have no effect.

To me, it seems like there's something related to fuel supply that is causing the problem. Many have suggested it could be a faulty temperature sensor. One mechanic friend said his wife's car had a similar isssue. For him, reflashing the software solved it.

Thanks for your input. I'll repost this in its own thread, as this really doesn't belong in this thread.

[foosh]

I don't know what you're describing as a "violent shake." You seem a little prone to hyperbole. If your clutch technique is awful, I could see you getting a pretty good jolt.

I see a lot of drivers who think they know how to drive a manual, and when I ride with them, I'm surprised at how bad and massively jerky they are.

At any rate, you said it was a 2 minute issue, and you knew how to prevent it with driver technique. What is the problem?

[WHM3]

Originally Posted by foosh

I don't know what you're describing as a "violent shake." You seem a little prone to hyperbole. If you're clutch technique is awful, I could see you getting a pretty good jolt. My money is on that.

And that's my point. You can't know what I'm describing. I'm doing my best to describe it, but clearly I'm not finding the right words, and for that, I apologize.

As I mentioned, it has nothing to do with shifting. I can keep the car in first, shift to second... it really doesn't matter. But as soon as the engine hits 2700rpm, the shake happens.

But, nothing I say will convince you that the car itself actually has a problem. And, there's no way for you to see the problem for yourself. So, there's no point in continuing with this conversation.

Thanks again for your input.

[Finnegan]

Originally Posted by foosh

Well, this is pretty normal on many manuals when cold. I see it on my E93 M3 for maybe 2 minutes after a cold start, and get around it by modulating clutch and throttle, as you seem to have learned. I've experienced it on many other manuals as well, including my RS4. The reason the dealer couldn't find it was they likely thought it was normal and didn't notice it while using the right technique, or they warmed the car up for more than 2 minutes before driving it.

This engine is not a torque monster down low, as opposed to something like the LS7 in a Z06, which would pull in 4th gear at 2K rpms from a standing start. When cold, it will balk even more without a few more revs.

Bottom line is, I don't think you have a problem. If you think that 2 minute inconvenience is a major problem, I'd be worried about you.

Foosh is right on. Mine does this as well. The engine is in "heat the cats" mode on startup--and the engine is balky. (Same thing with a couple of MY07 MT Mustangs I drove during winter.) This is normal for this car. I suspect the extra 400 lbs. on the vert makes it more likely too than on the coupe or sedan.

It takes a certain "art" with the clutch/gas to avoid looking like you're 16 and driving your first stick. I can, if I want to, easily make the car buck like a bronco when it's cold. I can't reproduce that effect very easily when it's warm. Not that I'd want to do that in either case that would mean my technique needed improvement.

The only software flash I know of that would "fix" this is the AA flash which eliminates the "heat the cats" cycle.

[Finnegan]

Originally Posted by weshsu

And that's my point. You can't know what I'm describing. I'm doing my best to describe it, but clearly I'm not finding the right words, and for that, I apologize.

As I mentioned, it has nothing to do with shifting. I can keep the car in first, shift to second... it really doesn't matter. But as soon as the engine hits 2700rpm, the shake happens.

But, nothing I say will convince you that the car itself actually has a problem. And, there's no way for you to see the problem for yourself. So, there's no point in continuing with this conversation.

Thanks again for your input.

Yep, that's the RPM range when it will buck like a bronco alright. It happens when fully in gear with the clutch fully disengaged. Like I said, I can make it happen (or not) based on how smoothly I release the clutch and how I throttle. It will happen based on the smoothness and sequencing of clutch release + throttle before fully in gear--that sets up the "buck" down the line at the RPM range described. Pushing in the clutch a bit will stop the bucking. I just chalked this up to something that comes along for the ride with a high-performance engine and drivetrain and my sometimes less than stellar early AM driving technique!

Then again, since we're not riding in your car, there may be some other issues or what you're experiencing may be different. In any case, I wish you the best of luck getting this issue resolved.

[WHM3]

Originally Posted by Finnegan

Foosh is right on. Mine does this as well. The engine is in "heat the cats" mode on startup--and the engine is balky. (Same thing with a couple of MY07 MT Mustangs I drove during winter.) This is normal for this car. I suspect the extra 400 lbs. on the vert makes it more likely too than on the coupe or sedan.

It takes a certain "art" with the clutch/gas to avoid looking like you're 16 and driving your first stick. I can, if I want to, easily make the car buck like a bronco when it's cold. I can't reproduce that effect very easily when it's warm. Not that I'd want to do that in either case that would mean my technique needed improvement.

The only software flash I know of that would "fix" this is the AA flash which eliminates the "heat the cats" cycle.

Well, that's good to know that I now have 2 data points saying that it's normal, but I'd still like to have someone more knowledgeable than me witness it and concur with you guys that I just have to find ways to deal with it.

I do appreciate the technical details of what is probably going on.

Thanks for your input, Finnegan. I'm hoping I'm now down to just one set of issues... my leaks! (trying to get back on topic)

[WHM3]

Originally Posted by Finnegan

Yep, that's the RPM range when it will buck like a bronco alright. It happens when fully in gear with the clutch fully disengaged.

Well, then it looks like Foosh was right on. I just suck at 7AM shifting on this particular car. I didn't realize there was such a difference between this beast and my previous M3 when it comes to shifting from a cold start.

It's comforting to know that these exact criteria can cause it for at least one other. It's harder for me to say there's something wrong with the car then.

[Finnegan]

Originally Posted by weshsu

Well, that's good to know that I now have 2 data points saying that it's normal, but I'd still like to have someone more knowledgeable than me witness it and concur with you guys that I just have to find ways to deal with it.

I do appreciate the technical details of what is probably going on.

Thanks for your input, Finnegan. I'm hoping I'm now down to just one set of issues... my leaks! (trying to get back on topic)

May I suggest finding some local folks with a E9x M3 6MT? Local meetups (see the regional section) are great resources, as is this board. Get your buddy (or two) with a 6MT to come over and drive it when it's cold. That should provide some good data to work with.

And sorry about the leaks. I don't really drive in the rain, but hand washing (two bucket + hose) hasn't resulted in a single leak. Now my (now gone) 335 coupe? That's another story! I'd always have a drop or two on the drivers side window when washing.

[southlight]

Originally Posted by weshsu

If we need to, can this part of the thread be moved into a new thread?

Welcome aboard! Following your suggestion, I moved the posts related to your acceleration thread into this new thread.


Best regards,
south

[quackman]

I've had the same problem happening once in a while since I got this car and my '06 330i before it. Cold starts in the morning shifting weirdly makes the car buck like a bronco, yes kinda violently. It is not a problem with your car.

[thetoecutter]

Had to chime in here. The very first time I pulled away from the dealership in my one and only M3 test drive, I had that thing bucking like a bronco. E90M3 6MT. Thankfully, the dealer had just tossed me the keys and I was solo (that's what you get for being 40+ and arriving in a clean 550i) but it was still very embarassing until I quickly stabbed the clutch, rev'd the shit out of it and released the the clutch again slowly.

Got spoiled with my 550i 6MT for the past seveal years. You can start that in first gear with no throttle if you are careful and you can also easily start it from stop in second with slight throttle. Never bucks as it is a torque monster. But I am already preparing myself for the M3 - whole different motor that needs more revs to be smooth.

[foosh]

Originally Posted by thetoecutter

Had to chime in here. The very first time I pulled away from the dealership in my one and only M3 test drive, I had that thing bucking like a bronco. E90M3 6MT. Thankfully, the dealer had just tossed me the keys and I was solo (that's what you get for being 40+ and arriving in a clean 550i) but it was still very embarassing until I quickly stabbed the clutch, rev'd the shit out of it and released the the clutch again slowly.

Got spoiled with my 550i 6MT for the past seveal years. You can start that in first gear with no throttle if you are careful and you can also easily start it from stop in second with slight throttle. Never bucks as it is a torque monster. But I am already preparing myself for the M3 - whole different motor that needs more revs to be smooth.

Trust me, it's a cold engine issue only, which lasts for about 2 minutes, and that is consistent with your test drive account. You don't need to "rev the s... out of it" for normal starts after that. You don't even have to rev it at all, and it will start in first gear just exactly like your 550.

[JCtx]

As everybody said, it's normal, but only if you want it to be. You can easily avoid that doing one of several things: warm up the car a bit, stay out of that rpm range in low gear, accelerate a bit harder... etc. No car is perfect, and engines don't like to run cold, so you can always expect cold fueling issues on any car. Same with motorcycles; I can make them buck like a wild bronco if I want to, but I avoid it. Consider it another challenge to learn to be even smoother on a manual . That's why I love manual cars; you can always be smoother, so it's a continuing challenge to be ever smoother and smoother with gear changes, cold engines, down shifting, rev matching, etc. You never stop learning how to improve on your manual driving .

[foosh]

Originally Posted by elp_jc

As everybody said, it's normal, but only if you want it to be. You can easily avoid that doing one of several things: warm up the car a bit, stay out of that rpm range in low gear, accelerate a bit harder... etc. No car is perfect, and engines don't like to run cold, so you can always expect cold fueling issues on any car. Same with motorcycles; I can make them buck like a wild bronco if I want to, but I avoid it. Consider it another challenge to learn to be even smoother on a manual . That's why I love manual cars; you can always be smoother, so it's a continuing challenge to be ever smoother and smoother with gear changes, cold engines, down shifting, rev matching, etc. You never stop learning how to improve on your manual driving .

Bless you my friend!!!!!!

The quest for "smoothness" in driving a manual is an art form, and one can always get better no matter how many years of experience. I happen to have 36 years of experience on more than 50 cars, and I can still get "smoother."

Moreover, every car is different, and it takes a minimum of several months to get acceptably "smooth" every time you switch rides. Now, my definition of "smooth" is off-the-charts high, and I'm sure there will be many who chime in claiming they are already "smooth." Please understand that I'm talking an entirely different level of "smooth."

I sense that you understand what I'm talking about ELP. Few do.

[Mighty M]

Driver error. Take it to the dealer, they will confirm.

[Finnegan]

Foosh and elp_jc, I think I'm on the same page with you guys. Maybe I'm a "chimer"--in any case here's my definition of smooth:

MT nirvana is when you're passengers have trouble telling you've shifted up or down (other than engine speed); revs match perfectly up/down and there's no sense of change in the motion of the car. Almost "DCT" like if you want to put it that way. That's what I consider the black belt level of smoothness.

I haven't reached that level yet, but after 30 years of driving a stick I have periods when I'm 100% focused where I can row up and down through the gears for short periods of time where it's like there's no gear changes (other than change in engine speed) occuring at all. This is by no means consistent, but there are small windows into how it could be if I continue to strive for it.

I can hit the zone more frequently for longer periods with my DD, which I've got 165K miles on and 12 years of driving in. I replaced the original clutch at 156K miles which I hope speaks to some level of "smooth". I'm sure I'd not pass the "Foosh test" but I think I might have hit some decent white belt level of smooth.

With the M3 I've got the cold starts mastered most days. No bucking bronco action. But I've still got a way to go with being happy with even a white belt level of smooth for most driving. It's better the more I drive the M3. It seems like the goal of being super with each car I drive is always just out of reach, and trying to reach it is part of the fun of a MT (for me).

All this said I'm not sure I'd want either of you in the grading my performance--I think you guys are probably more at the black belt level !