BimmerFest BMW Forum banner

X5 can only go up step hill in reverse..is this normal?

10K views 67 replies 29 participants last post by  Emission 
#1 ·
Hi folks,

I just got a x5 35d 2010. It's on winter tires. I have been visiting friends that have a place in the mountains and every time I try to go up their driveway which is about 60 feet of a steep climb, I can never get up more then 20 feet before the car stops in dead in the tracks. I have turned off dsc, but then the car but starts spinning and moving from side to side..

But if I go up the same hill in reverse, I can go up the entire hill no issue.

They have a Subaru outback which goes up no problem.

Therefore, has anyone experienced this before, is it my tires, or is it that the xdrive can't handle it. It's disappointing..;-(

Thanks
Sami
 
#3 ·
Hi,

Here are more details.

So, when I get to a very steep hill, in this case the driveway covered of snow and some ice, when I accelerate to climb up, the x5 can't go up more then 20 feet. At this point it just stops like it has no more power. I guess this is the dsc kicking in.
Therefore I go back down the 20 feet, turn the x5 around and go up the steep driveway in reverse.
This way no issues, the x5 goes all the way up the 60 feet of steep driveway.

If I try again to go up the driveway and turn of DSC, this time at 20 feet up, the tires are spinning and x5 can't get up the rest of the driveway.

So my question is why am i able to go up the hill in reverse but not in drive. Does it have to so with how the x5 shares the power to the wheels. More in back, less in front. If it were my tires, wouldn't I not be able to go up anyways?

Thanks

Sami
 
#4 ·
That's crazy! I fully understand your disappointment! My first thought was that you must be running summer tires, but your post clearly states that you're running winter rubber.

I think you should post a video on YouTube showing your (mis)behavior with DSC turned on, then with it off, then after the "long press" (I'm not sure how that differs, but to capture the third method). Certainly one of the methods should get you up the hill, preferably the default.

I can't answer your question with any authority, but I'll bet that (A) you've found a hill that XDrive can't handle and (B) it's "within spec" although my vote is that this is very abnormal. :thumbdwn:

Perhaps your friends should remove some of the snow and ice before your next attempt. :rofl:
 
#11 · (Edited)
I was about to reply "LOL", but then I thought "Hmm... could be something to it".
http://www.barrystiretech.com/directionalandasymmetricaltires.html
"If you mount a directional tire backwards - so that it is rotating the wrong direction - the only problem caused is wet (or snow) traction."

The very first winter after I just bought my 35d (18" Dunlop RFTs), we had a lot of snow in Seattle, so I went to see how the X will handle some of them around my neighborhood.

Saw a guy on Range Rover (LR-something, 5 or so year old vehicle) attempt to get to his home up a steep hill. Granted, he had oversized rims and thin tires. So, he couldn't make it after multiple attempts.

I attempted the same hill (without turning off DSC) and got up the hill without a problem. I could feel the X5 switching torque to various wheels - the vehicle was kind of jerking forward every half second, as if it was able to find dry asphalt and getting traction. But I knew there was no way the tires got to the asphalt. The guy before me attempted that trick ("digging" through snow by spinning wheels) with no success.

Used hill descend control on the way down - awesome feeling of being completely in control while coming down slippery and snowy hill at exactly the speed I desired.
 
#6 ·
Hi folks,

I just got a x5 35d 2010. It's on winter tires. I have been visiting friends that have a place in the mountains and every time I try to go up their driveway which is about 60 feet of a steep climb, I can never get up more then 20 feet before the car stops in dead in the tracks. I have turned off dsc, but then the car but starts spinning and moving from side to side..

But if I go up the same hill in reverse, I can go up the entire hill no issue.

They have a Subaru outback which goes up no problem.

Therefore, has anyone experienced this before, is it my tires, or is it that the xdrive can't handle it. It's disappointing..;-(

Thanks
Sami
Curious how steep of a grade we're talking about? Pics or vid?

I live in the mountains and encounter as much ice and snow as anyone here and have never had an issue climbing hills around here with either our Scorpions or Blizzaks? :dunno:

Are your tires almost done? We also have a '10 and are on our second set of winter rubber now. End life of the last set was less than ideal.
 
#7 ·
Normal: depends

I would try all the possible permutations of the dsc and dtc active and inactive and possibly manual mode see if anything works.

The situation ur describing is probably ur tread life or lack thereof. If u have winters on, ur nannies should complement ur steep hill Climb (if operated as per the manual). However if Ur close to replacement time, the only reason I can think of why ur able to sucessfully climb in r, is due to the rear biased x drive. (ergo if ur stuck in a rwd car, reverse will be a better option than d, while a fwd car forward is the better option).
 
#9 ·
This may sound totally ridiculous (I apologize to those who are much more mechanical than I will ever be) but lets say no power is going to your front wheels for some reason. If you are going forward, it's like you are driving a real-wheel only vehicle. But if you turn the vehicle around and go up in reverse, it's like driving a front-wheel drive car so you may be able to "pull" up. Probably not the reason - just trying to figure it out - I guess true front-wheel drive cars also benefit from having the engine weight on the drive wheels. Experts please don't chastise me.
 
#10 · (Edited)
Stoubal,

Just wondering. Are your winter tires 18", 19" or 20"?

I used to have fantastic grip with my 18" winter tires --- haven't fully tested my current 20" winters yet...

And to answer one of your questions. I have read that 62% of the power is supplied to the rear wheels. Another source said 68% so not sure which number is correct.
 
#20 ·
Stoubal,

Just wondering. Are your winter tires 18", 19" or 20"?

I used to have fantastic grip with my 18" winter tires --- haven't fully tested my current 20" winters yet...

And to answer one of your questions. I have read that 62% of the power is supplied to the rear wheels. Another source said 68% so not sure which number is correct.
I too have heard conflicting reports:

a) the x drive below highway speeds is a 40-60 system (fw-rw)
b) The system is capable of sending 50% power/100% torque to each axle
c) At highway speeds, the system establishes 50% power/100% torque to the rear axle.
 
#15 ·
It's disappointing..;-(

Thanks
Sami
Actually this is a well known problem with the X5, but BMW has successfully covered it up. It is regularly discussed here on the forum, but as soon as the thread pops up it is deleted.

It is unusual that this has stayed up so long....

In snow country it is common to seen X5s clustered at the bottom of steep hills while other traffic passes them by...indeed, quite a few drivers have been cited for backing the wrong way up hills as well.

BMW should be embarassed.
 
#16 ·
I wouldn't call it the best system, but Xdrive seems to handle snow pretty well - I have given an example above. Granted, I live in Seattle and we dont get much snow unless venture out to the pass or up to Vancouver ski area. But I have found myself pretty comfortable up there. I did see vehicles that are supposedly good AWD not able to start off on slippery surface (Nissan Xterra). Maybe there's a driver component to it.

The X5 acts differently when it's very slippery. While another (traditional) SUV would lose grip at the front tires and just slide straight forward when attempting a turn (understeer), the X5 tends to slide the back (oversteer) - probably due to rear wheel bias?. I found that I prefer that behavior, since it gives more control.
 
#17 ·
I may have missed this, but assume that you have tried manually shifting down to first or second? I spend a lot of time in the Colorado foothills and, so far, have not had any issues.
 
#18 ·
Hi all,
thanks again for your many comments, suggestions and ideas. To answer some questions from some of the replies, I'm on 18 inch wheels, haven't tried it in manual mode.

On Friday I will be trying to go up again the steep slope and I will film the slope and also show my x5 trying to go up in forward and in reverse.

Btw, I called the dealer and they think it might be a problem with the awd system.

I will update this thread on Friday. Thanks again.

Sami
 
#23 ·
Wow.
 
#24 ·
If it's in response to my above post then I can assure you my interest is sincere. Some pointers to more information would be appreciated, since you spoke so knowingly on the subject...
 
#26 ·
Don't worry, in exhange for their great offer I will give them a perfectly working bridge nearby.

Oh just spell it out for me guys, please. I am having a **** day at work and now you are saying I am missing a ton of sarcasm. Just great.

But, on the other hand, at least I have something to smile about now - thanks! :rofl:
 
#32 ·
Whew! He had me! :thumbup:

- Mike
 
#34 ·
Stoubal - that's what i was wondering when I mentioned going backwards up the hill in a rear-wheel drive vehicle is sorta like going forward in front wheel drive - if AWD not working your X5 is rear wheel only. I know - this is way out there. I don't know if AWD could fail that way.
 
#35 ·
What you are describing sounds all wrong, but it is possible that BMW's electronically based AWD is configured to act differently in forward vs. reverse. Odd, but possible.

- Mike
 
#36 ·
Sorry but my entire post was tongue in cheek. I mean the part about finding X5s clustered at the bottom of hills was the dead give away/... I thought.


All in good fun!
 
#37 ·
Sorry but my entire post was tongue in cheek. I mean the part about finding X5s clustered at the bottom of hills was the dead give away/... I thought.

All in good fun!
That's what happens when I only read a couple posts!

Plus, it's about 80F here today... As if I know anything about snow performance.

- Mike
 
#42 · (Edited)
First of all, having just flamed a noob on another thread who asked some really stupid questions (answers to all of which were in the manual), I would like to start by CONGRATULATING the OP for doing his research first and asking an intelligent question (with intelligent follow ups). I can be the second most sarcastic guy here (cough, cough, ard), but I am sincere when I say WELL DONE.

My thoughts on the question.

First, unlike a "serious" SUV, the X5 has neither Torsen diffs nor locking diffs. I seem to remember that some Subies have Torsens, so that could explain part of the difference.

Second, what the OP is experiencing on his first run up the hill (with DSC turned on) is the ECM sensing spinning wheels, applying brakes, and ultimately dialing back the power. There simply isn't enough traction between the contact patches of his tires and the surface to get a "grip".

The X5 gives you 3 options: (1.) DSC on, (2.) DSC off but DTC on, and (3.) both DSC and DTC off. In soft sand and deep snow, you are almost always better off in mode #2 (DTC on), and in some cases (rocking yourself out of some nasty deep sh*t) you may want to be in mode 3. So if the driveway was covered in SNOW, you want to select mode 2 or mode 3. But neither of those modes do you any good on ICE, and the OP states the driveway was covered with BOTH snow and ice. For traction on ice, you need a locking diff, a Torsen diff, studded tires, chains, sand, kitty litter, or winter tires with an ice-friendly tread compound (hydrophilic).

Third, the OP's "winter" tires may be M&S tires, designed primarily for traction in soft snow (i.e. lots of sipes). They may not have the same compound as a tire designed too perform well on ice (like various Pirelli and Michelin tires).

So why does the X5 go up fine in reverse? Part of it may have to do with the lower gear ratio. But I suspect that weight distribution may also be a factor. And it is also possible that his front tires are worn on the outsides from cornering, and his contact patches are more uniform on the rear axle.

(BTW Did you try out HDC coming back down the driveway? IMHO HDC is one of the best features of xDrive, and most owners are blissfully unaware of it).
 
#43 ·
I am learning stuff here:

"xDrive is the permanent all-wheel drive system from BMW: under normal circumstances, it distributes driver power between the front and rear axles in a 40:60 ratio, and changes this figure variably when the road surface or overall driving conditions change.
Acting virtually instantaneously and a manner so subtle as to be go virtually unnoticed by the vehicle's occupants, xDrive can direct up to 100% of drive forces to one axle. Enabling the driver to start up effortlessly even on slippery surfaces or steep hills, xDrive routes all power to the axles with the greatest traction. When parking, the system reacts to the need for high manoeuvrability at low speed by opening the clutch completely so the powertrain functions optimally. At the first sign of understeering, drive power to the front axle is reduced. If oversteering is detected, xDrive directs more power to the front axle. Thanks to this dynamic redistribution of power, vehicle stability returns to normal even before the driver notices anything amiss."

It appears that the system is able to split torque fore and aft up to 100 percent, but if one wheel slips on the axle it applies the brake to send power across... it does not lock the axle.

- Mike
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top