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Throttle Hesitation - DRIVING US NUTS!!!

36K views 102 replies 33 participants last post by  Vicsonryan 
#1 ·
OK, we have had our X1 a few months, and it's really a second car, but in the few (1500) miles we have driven it we have been repeatedly honked at and been in a couple of close calls because of the stupid throttle hesitation. There is always about a 1 sec lag between pushing down on the pedal and the engine kicking in. It doesn't matter if you push down harder on the throttle, because then when it does kick in it is just more throttle.

My suspicion is that this delay has something to do with the Auto Start Stop (code named ASS for a reason), which we had the dealer default to off, so we don't have to deal with it. I have a feeling that by this time next year, the ASS function will be no more.

So are other people having the same problem? Or do we need to take the car back to the dealer to be inspected?

Seriously, a full second between pressing on the pedal and having the car respond!
 
#9 ·
Yeah I read the thread - that was dealing with what sounds like an actual misfire or hesitation under acceleration when the car was already moving. I hoping to find out if everyone experiences this pretty consistent this one-second delay when accelerating from a stop with ASS off, in D. I'd like to know if there's a problem with our X1 or if BMW just blew it and programmed every ECU in hopes of saving fuel (which in this case seems to do the opposite).
 
#3 ·
This has nothing to do with ASS. :bigpimp:

The throttle delay is programmed by BMW for your own protection (fuel conservation). :rolleyes:

Throttle response is worst in ECO PRO. It should be better in D/Drive and best in S/Sport.

There are also aftermarket solutions which improve throttle response.
 
#8 ·
We never drive in ECO PRO. How does BMW figure it's saving fuel when you end up stomping down on the accelerator even more during the delay, then having the car take off unexpectedly when the ECU finally decides to send fuel to the engine?
 
#4 ·
So are other people having the same problem? Or do we need to take the car back to the dealer to be inspected?

Seriously, a full second between pressing on the pedal and having the car respond!
Phew... glad to hear that everyone is experiencing this issue. I though I was beginning to lose feeling in by right foot.

I does make it tough to accelerate smoothly from a stop. I hate those jackrabbit starts.
 
#5 ·
Have a read of the sticky in the X3 forum. Wonder if it is related?
 
#6 · (Edited)
#13 ·
The delay happens before the transmission even sees any torque. The engine sits quietly for a full second after depressing the accelerator before responding at all, so why would it be different with the 3.0L/6sp? Same ECU I bet. Anyone with the 3.0 see this too?

Expecting the BMS unit in 2-5 days... I'll report back in a new post after the install, hopefully on the weekend. We're at about 2k miles now, so I feel comfortable changing the maps a bit. Won't drive it too hard though, I promise! Even if the unit only remapped this stupid drive-by-wire delay, I would be happy...
 
#15 ·
I'm amazed that BMW refuses to address this issue. They may have good intentions with throttles that fight back, runflat tires and ASS, but the features detract from the driving experience so much it has to have an effect on repeat sales. Should you really have to go to the aftermarket to get decent throttle response? On a BMW?!?!
 
#17 ·
I'm amazed that BMW refuses to address this issue. They may have good intentions with throttles that fight back, runflat tires and ASS, but the features detract from the driving experience so much it has to have an effect on repeat sales. Should you really have to go to the aftermarket to get decent throttle response? On a BMW?!?!
This is definitely true for me. When we test drove the X3, Q5 and Volvo XC60 the X3 had such horrible tip-in it was a huge black mark against it. We ended up with the Volvo (traded in our 530i for it). This was before the X3's tip-in software fix was released this past spring. Even now, that fix seems to be only a partial fix...tough to tell over on the X3 forum if it has stuck.
 
#16 ·
Wow, if you search "hesitation" there are a bunch of threads related to older engines/models. They refer to the hesitation as "tip-in" also. Seems like BMW has attempted to address the issue in other models by updating the software maps. I can't find anything about the N20 and hesitation yet though, except for that earlier thread in this forum where some people mention also experiencing it, but that was also discussing misfire under acceleration which this definitely is not.
 
#18 ·
I recently test drove an SDrive X1, an xDrive 35i X1, and a loaded M Sport 35i X3 and I remember being surprised by the drive by wire lag on the SDrive and X3 ( the X3 really lurched too). I know that the drive by wire programming is separate from the transmission but the X1 35i with the six speed did not leave me feeling like there was the same dead zone in the pedal/throttle lag or lurching, perhaps it is just different programming. I drove in manual mode/sport with all three
 
#23 ·
Isn't the 2011 X3 28i the old N52 inline6 with a 6speed? This is about what I observe on our E82 and E90, no more than a half second delay.

Are people experiencing a full second with the 8AT? I have not noticed a full second on the F30 (or the X1s I've test driven), even in ECO PRO.
 
#27 ·
I sure am glad I found this thread. Now that I am approaching 200 miles on my X1, I've been quite aware of this silly throttle lag for some time. It only took about 20-ish miles for me to realize that the delay was "just how the car is." The acceleration is about as linear as a Mobius strip! I give the pedal a full inch; car acts like a sleepy dog being poked with a stick to move. Once it gets going, even a tiny increase in pedal pressure brings on a more acceptable rate of acceleration. :)

If either of these BMS devices will make the pedal act like that from the beginning, then I'll be all over it. I will be anxiously awaiting results on how well this works for our X1's!
 
#28 ·
I've got some experience with aftermarket mods, having put on a few aftermarket superchargers, piggyback computers (that involved splicing into the ECU wires), swapping injectors, ect. The BMS unit seems truly plug and play. If I throw a code then I'll go with the CAN unit or anther aftermarket code reader. I'll start a new thread when I get this all going.
 
#29 ·
Thank you very much for posting this thread.

The EPA test is a very specific procedure. If the car makers would wise-up, they would program the computer to recognize that it was on such a test routine, and behave as buyers want otherwise.

Our C230K and Explorer have no such stupidity! I'm sure I'd notice it if the ones I drive have it, especially sicne I won't buy a vehicle I'm not familiar with unless I've had a good long (75 to 125 mile) test drive in assorted traffic.

I've got expereince with turbo and super-charged cars, going back to my 1984 Sunbird with the 1.8 turbo and manual transmission.
 
#30 · (Edited)
My X1 is still a few weeks away (en route to the Panama Canal at the moment). I did do some driving in our 128i and my parents' F30 328i (xLine with everything on it).

The 128i and the 328i are both noticeably more responsive and peppier in DS/Sport mode. However, the lag in Drive/Comfort does serve a purpose. In these vehicles, the drive is a bit smoother and perhaps more luxurious in Drive/Comfort, DS/Sport can be a bit too sporty/responsive for normal driving. ECO PRO is just too numb for my taste and makes the car feel like a base model Camry. I'm driving my S2000 until the X1 gets here and I have come to appreciate Drive/Comfort for long commutes.

When using paddles in D/Drive in the 128i, you still get the delayed throttle response vs DS. I use the paddles mostly for passing on the freeway. The auto does a great job on its own in DS mode when needed. I may just start using DS instead of paddles like my wife does. The downside of DS is that it never shifts into overdrive (6th) on the 128i. I'm not sure how it behaves on the 8AT but I'm sure it keeps gearing low and revs high just like the 6AT.

My parents like the luxurious feel and would rather mash on the gas for power than use sport mode (they don't have paddles). They drive mostly in ECO PRO to conserve fuel. I showed them how to quickly move into DS and back when they need responsiveness for a moment. They also like the light steering while I prefer the stiffer steering of Sport mode. With DS they keep the lighter steering vs moving to sport mode with the rocker switch. The F30 is a bit different than the X1 in this regard, which of course doesn't offer adaptive sport steering and suspension. If it did, I would have chosen the sDrive over xDrive.
 
#31 ·
Just a quick note for reference: there is still substantial tip-in lag when driving in "M" mode. Meaning when stopped at a stop sign, manually shifting into 1st, the engine still hesitates to accelerate, although the hesitation is not as long as in D mode. It's about the same in M as DS. Still much too much lag for me. But my other car has the pedal connected to the throttle body with a physical cable - so that is what I'm used to. ECO PRO is a joke. Maaaaaaybe if driving on a long trip on a flat freeway with cruise control on. Otherwise why buy the BMW in the first place - just to impress the neighbors?
 
#32 · (Edited)
Yes the lag is unacceptable. Maybe acceptable for a Toyota Prius, but not a BMW.

You should bring it back to the dealer to check whether there are any software updates for your x1.

But at the meantime, you can try this throttle adaptation reset procedure:
1. Keep your foot off the brake and hit the start/stop button.
2. Hold the gas pedal down (all the way down) for 5 seconds.
3. Switch off the car while holding the pedal down.
4. Done

You should see a slight improvement.
 
#36 ·
Quick update: installed the Burger Tuning N26 stage 1 today (formal thread and writeup pending). Initial impressions, no change with the tip-in in D, but it is reduced by about 1/2 in DS. The car flies like a bat out of hell in DS, however. That's fun. Just a quick drive around the block and it feels like a whole new beast! A bit disappointed that the throttle hesitation issue wasn't fixed in D, however glad that now I have the option of mostly eliminating it in DS. I'm sure BMW will offer ECU upgrades for the tip-in like it sounds they are doing for the other N52/55 engines, but likely won't happen any time soon with the new model.

Insofar as the install went, it took me about 45 minutes, only because the instructions aren't specific to the X1, and there are some minor differences I had to figure out. If I had to uninstall it, or re-install it, it would literally take me less than 5 minutes.
 
#38 ·
So grey, it sounds like the kit provided some nice improvement everywhere, except the area I was hoping it would fix the most. :D

Aside from tip-in not really getting addressed while in D, I'm curious to find out how you feel about the advertised HP gains from this kit. I've enjoyed the need-more-HP bug for some time, and the one thing I've leared is that HP isn't cheap. If it is, then something is wrong. HP, reliability, and cost... pick two of the three. This kit advertises some pretty remarkable gains, especially for the price; so naturally I'm taking that with a HUGE grain of salt. I had planned to pick this kit up, if for nothing else than to fix the throttle lag, but if there is actually a noticeable increase in power, for example if BMW REALLY left that much HP on the table by not tuning it like BMS just did, then i might go for it anyway. It's just that when I see items that run $10-$15 per HP offered, I am very skeptical. :D

I'm glad the initial review was favorable!
 
#39 ·
The seat-of-the-pants gains from the unit are substantial, although to realize the max (60) HP increase advertised on the site you need to run high octane and a more aggressive map. The standard map is definitely enough to get your attention. Keep in mind that BMW developed and raced a 2L inline 4 cylinder F1 engine that produced 800 hp. I think they know a bit about small displacement potential! The little BMS unit definitely delivers in the HP/$ ratio. My other car is running an aftermarket supercharger, fuel mods, plus headers at the tune of $3000 or so, and the gains are MAYBE 100 HP (although more like 70). So at best, $30/HP, but probably more like $40-$45/HP.

In so far as the hesitation is concerned, I need to drive the car a bit more to really get a feel for whether the tip in has improved ... The fact that it has been bothering me so much recently, coupled with an email from Terry Burger that the throttle lag issue was addressed, really set me up for disappointment that it wasn't entirely eliminated with the tune. I don't know if I'm overly sensitive to it now or what, or if Terry only meant that it was addressed in DS. The nice thing is that the unit is reprogrammable. If enough of us provide feedback to BMS, maybe they would offer a more aggressive D-map? I don't know...
 
#47 ·
thanks for the write up grey.

like others i'm saddened by the lack of affect on the tip-in.

i may want to get the Stage 1 down the line but like many here its a family car and an everyday driver. which means traffic and kid hauler. so it doesn't make sense for me at the moment. if it fixed the lag it may be a different story.
 
#52 ·
Awesome, thanks for that link!!!!

I got my X1 xDrive28i about three weeks ago. I didn't notice the acceleration lag so much at first, but now it is starting to drive me crazy and feels dangerous when I am trying to pull into traffic. At its worse I think it is a few seconds from the time I push down the accelerator to anything happening.

Has anyone tried the Throttle Body Adaptation reset mentioned in this thread?

It looks like a software update fixed the 5 series acceleration lag issue. I am contacting my dealer about my X1. If enough of us speak up, hopefully BMW will release the same fix for the X1 series.
 
#55 ·
Keeping my 2006 Explorer V8 is looking more attractive the more I read. I wonder if the 2014 Jeep Grand Cherokee with the 8-speed will have the same problems? My guess is that the transmission is too light to handle the torque, due to the crazy CAFE regulations, so they slow application of the engine torque to prevent excessive warranty work on failed transmissions. There are several versions of the ZF 8-speed.
 
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