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E39 (1997 - 2003)
The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

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  #1  
Old 12-15-2004, 11:48 AM
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Violent shudder when braking after hitting bumps

I've noticed that my car shudders badly when braking while passing over larger road imperfections (expansion joints, potholes). My Integra is fine when I go over the same. Is there something wrong with my 525iT or is this just normal for the car?
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  #2  
Old 12-15-2004, 11:56 AM
craigt-from-atl craigt-from-atl is offline
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Quote:
Originally Posted by LA525iT
I've noticed that my car shudders badly when braking while passing over larger road imperfections (expansion joints, potholes). My Integra is fine when I go over the same. Is there something wrong with my 525iT or is this just normal for the car?
Is it only after hitting bumps, or does it do it all the time while braking? Shuttering under braking tends to be warped rotors. How many miles on the car/brakes?
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  #3  
Old 12-15-2004, 12:11 PM
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hmmmm........that happened to me last week. I did a hard brake after I went over a small ditch and all of a sudden, the car started to have a seizure or something. But it was just that one time. My car has over 98,500 miles. I've been more cautious whenever I brake now. I'll keep tabs on that to see what gives........
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Old 12-15-2004, 12:12 PM
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You sure it's not just the ABS activating?
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  #5  
Old 12-15-2004, 12:15 PM
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Quote:
Originally Posted by Plaz
You sure it's not just the ABS activating?


you could be correct
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  #6  
Old 12-15-2004, 02:23 PM
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Quote:
Originally Posted by Plaz
You sure it's not just the ABS activating?
I'm not braking hard, usually just downshifting and gently braking to a stop (I'm talking about an expansion joint on the Main Street bridge over the 10 freeway in Santa Monica).

Could be the ABS triggered, but seems like a much more pronounced shudder through the pedals.

Car has 18,000 miles on it, 1.5 years old and I'm the original owner.
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  #7  
Old 12-16-2004, 07:46 AM
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Quote:
Originally Posted by LA525iT
I'm not braking hard, usually just downshifting and gently braking to a stop (I'm talking about an expansion joint on the Main Street bridge over the 10 freeway in Santa Monica).

Could be the ABS triggered, but seems like a much more pronounced shudder through the pedals.

Car has 18,000 miles on it, 1.5 years old and I'm the original owner.

If you applying any brakes and go over a bump that's the ABS kicking in and you would only feel it throguh the pedal. It feels like the pedal is pushing back against you because it actually is. The brakes are pulsating so that they do not lock up on you. This is normal for every car with ABS, I would imagine that your integra is not equipped with ABS. If you feel a vibration under normal braking conditions at highway speeds that is most likely due to warped rotors as previous poster stated. You have driven more than enough miles to have warped your rotors.
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  #8  
Old 12-16-2004, 08:55 AM
norcal 528i norcal 528i is offline
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My 5er does seem to activate the ABS more in those situations than my other cars. I bled the brakes and it now does it noticeably less.
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  #9  
Old 12-16-2004, 09:03 AM
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Quote:
Originally Posted by LA525iT
I'm not braking hard, usually just downshifting and gently braking to a stop (I'm talking about an expansion joint on the Main Street bridge over the 10 freeway in Santa Monica).

Could be the ABS triggered, but seems like a much more pronounced shudder through the pedals.

Car has 18,000 miles on it, 1.5 years old and I'm the original owner.
LA I know exactly what you are talking about, it is the ABS activation but very odd in deed, not the normal ABS activation, but a whole front end shuttering, and does not stop after you go over the bump, until you release the brakes.

It almost feels like the whole front end is going to shake apart.

It has happened to me 3 or 4 times in my 2001 530i and 2 or 3 times to me in my wife's 2000 740i, so I have never brought them in on this. Funny, they replaced the ABS/DSC computer in the 740 not to long ago, and it still happened. I have never asked about it but will next time.

But you are right, it is unlike any other car I have ever owned with ABS (I have had 4 others), it is not just a pulsating feeling through the pedal or a pump sound, or clicking sound, the whole front end shutters and bucks back and forth.

The 7er has less than 40k miles and my 5er has over 50k miles, I just thought it was normal, but alarming, under certain conditions (and not braking hard either). Maybe a software glitch.
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  #10  
Old 12-16-2004, 09:46 AM
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How can you expect every car to have the same exact ABS feel? That's like expecting every car to have the same steering feel. The know what ABS feels like when it kicks in on a car. I can't say that I can recognize the severity between this car and my previous cat but you should know what the ABS feels like and its as simple as that. Maybe there is a combination of the ABS and your rotors being warped.

When was the last time you guys changed your rotors? People you have bad braking habits (people who over brake or apply brakes by holding the brake down until they are at the speed they wish rather than applying brakes and releasing them allowing inertia to do its work) go through brakes and rotors quicker and tend to warp their rotors because they are always hot.
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  #11  
Old 12-16-2004, 10:08 AM
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Quote:
Originally Posted by dagoo98
How can you expect every car to have the same exact ABS feel? That's like expecting every car to have the same steering feel. The know what ABS feels like when it kicks in on a car. I can't say that I can recognize the severity between this car and my previous cat but you should know what the ABS feels like and its as simple as that. Maybe there is a combination of the ABS and your rotors being warped.

When was the last time you guys changed your rotors? People you have bad braking habits (people who over brake or apply brakes by holding the brake down until they are at the speed they wish rather than applying brakes and releasing them allowing inertia to do its work) go through brakes and rotors quicker and tend to warp their rotors because they are always hot.
Dagoo

Sorry, my rotors are not warped. When the steering wheel pulls left and right repeatedly until the brakes are released (even after the bump has long passed) and the whole car shutters badly at that same time, I know that it is not normal, have I complained, no, does it happen every time, no, but it does happen sometimes when I brake and go over a bump, and not heavy braking, not limit braking, but well modulated braking.

Rotors were replaced (full brake replacement) only 3k miles ago on my car and 10k miles on the 7.

Relax on criticizing others, we know what we are talking about.

Yes, not every car has the same abs feel, but whole car should not shudder, vibrate, or pull when abs kicks in (plus I have felt normal abs kick in on the car, so I know it is not the normal application).

If even you were driving my car when it happened, you would be quite alarmed the first time!

Be constructive, not destructive - Thanks
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  #12  
Old 12-16-2004, 10:45 AM
norcal 528i norcal 528i is offline
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I have let two people other than my wife drive the 5er. The first and only time my buddy drove it he entered a liquor store drive way (small bump) while putting on the brakes and the front-end-about-to-come-apart ABS activated. He looked at me like he just wrecked my car.

I am sure dagoo didn't mean his post the way it sounded, but if I am coming to a stop and there is a pot hole that I know might cause this phenomenon, I guess I should just disengage the brakes and coast into the back end of the guy in front of me. I am just glad that other people find the ABS in these cars a bit eccentric.
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  #13  
Old 12-16-2004, 10:53 AM
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Yeah must be the ABS I guess. My Integra has ABS (and a firmer suspension and shorter wheelbase to boot) and does not react at all over the exact same road imperfections.

BTW, rotors are not worn nor warped. My car only has 18k on it and I slow down with a combination of downshifting and gentle braking, so I'd bet my brakes are much less worn than a car with similar mileage and an automatic tranny.
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Last edited by LA525iT; 12-16-2004 at 10:55 AM.
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  #14  
Old 12-16-2004, 11:01 AM
paulwbenn paulwbenn is offline
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I have experienced this very problem in my '02 525i. Usually at low speed going over a railroad crossing or the like. I think its just ABS kicking in. I usually let off and reapply, and no problem.
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  #15  
Old 12-16-2004, 12:56 PM
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Damn I have experienced this too, hit a bump, brake and I thought the front end was going to fall off I was wondering whether it was the ABS and I agree that's the explanation.
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  #16  
Old 12-17-2004, 12:01 PM
shabbaman shabbaman is offline
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I've experienced this in my car several times as well. It's as if the ABS doesn't *let go*. Usually it's an expansion joint or a mild pothole and usually I'm driving no more than 5 miles per hour or so. The ABS kicks in and will not *let go* until either the car is fully stopped or the mechanism is "reset" by taking my foot off the brake pedal.
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  #17  
Old 12-17-2004, 03:11 PM
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Quote:
Originally Posted by shabbaman
I've experienced this in my car several times as well. It's as if the ABS doesn't *let go*. Usually it's an expansion joint or a mild pothole and usually I'm driving no more than 5 miles per hour or so. The ABS kicks in and will not *let go* until either the car is fully stopped or the mechanism is "reset" by taking my foot off the brake pedal.
Exactly, thanks to you and the others for your replies, at least I know it is not just my car
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  #18  
Old 12-17-2004, 03:15 PM
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Quote:
Originally Posted by E39spd
Exactly, thanks to you and the others for your replies, at least I know it is not just my car
Ditto!
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Old 12-17-2004, 03:53 PM
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Quote:
Originally Posted by E39spd
Dagoo

Sorry, my rotors are not warped. When the steering wheel pulls left and right repeatedly until the brakes are released (even after the bump has long passed) and the whole car shutters badly at that same time, I know that it is not normal, have I complained, no, does it happen every time, no, but it does happen sometimes when I brake and go over a bump, and not heavy braking, not limit braking, but well modulated braking.

Rotors were replaced (full brake replacement) only 3k miles ago on my car and 10k miles on the 7.

Relax on criticizing others, we know what we are talking about.

Yes, not every car has the same abs feel, but whole car should not shudder, vibrate, or pull when abs kicks in (plus I have felt normal abs kick in on the car, so I know it is not the normal application).

If even you were driving my car when it happened, you would be quite alarmed the first time!

Be constructive, not destructive - Thanks
My reply was constructive, the scenario you described are exact symptoms of warped rotors. Remember that the people on this forum cannot drive the car to tell themselves so they go by your descriptions. When a car has warped rotors, when you apply brakes at highway speed, 50mph and above, the steering wheel shakes from left to right and you feel the vibration in the front of your car until you let go of the brakes.

The fact that you brake and go over a bump should first clue you in on the fact that it most likely is your ABS kicking in. It also will not stop until you release the brake because that is what is designed to do, the whole purpose is to prevent the brakes from locking up and causing an unsafe condition. It forces the driver to release the brake and re-engage the brakes which ensures that the brakes will not lock up because of the bumps in the road. I simply was trying to explain that it was either your rotors being warped or your ABS kicking in, not quite sure how that's destructive.

I don't understand when people post here looking for answers and then get offended when others offer answers.

Thank you norcal 528i for understanding the intentions of my reply.
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  #20  
Old 12-17-2004, 04:02 PM
shabbaman shabbaman is offline
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Quote:
Originally Posted by norcal 528i
I am just glad that other people find the ABS in these cars a bit eccentric.

I wouldn't exactly call it eccentric. I would call it confused.

Also, another attribute of the ABS problem is the humming that is heard while the system is working. So the shudder in the front that you can feel along with the humming that you can hear together collaborate to make you think that your car is about to fall apart on the spot.
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Last edited by shabbaman; 12-18-2004 at 10:31 AM.
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  #21  
Old 12-17-2004, 04:21 PM
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Quote:
Originally Posted by dagoo98
The fact that you brake and go over a bump should first clue you in on the fact that it most likely is your ABS kicking in.
I (and I assume other posters who have had similar problems) currently own and have owned other ABS equipped cars and have not experienced this problem with others. Why I should assume ABS is beyond me. Only because it seems recurrent amongst others am I inclined to think design of car and its systems, hence ABS.
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  #22  
Old 12-17-2004, 07:29 PM
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Quote:
Originally Posted by LA525iT
I (and I assume other posters who have had similar problems) currently own and have owned other ABS equipped cars and have not experienced this problem with others. Why I should assume ABS is beyond me. Only because it seems recurrent amongst others am I inclined to think design of car and its systems, hence ABS.
I have experienced the speed bump problem in my old Land Rover. I guess it would be safe to presume that for a split second while the car is rebounding from the speed bump and the brake is pressed hard enough that a momentary instance of lockup is detected by the ABS sensors and begin to cycle the brakes.

The ABS sensors on all these cars are quick and are capable of picking up several hundred actions per second so I don't think it takes more than a momentary lockup to kick the system in.

To me, when this happens I consider it more of an annoyance than anything else. It's one of the only downsides to ABS I can think of.
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Old 12-17-2004, 08:19 PM
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Quote:
Originally Posted by dagoo98
My reply was constructive, the scenario you described are exact symptoms of warped rotors. Remember that the people on this forum cannot drive the car to tell themselves so they go by your descriptions. When a car has warped rotors, when you apply brakes at highway speed, 50mph and above, the steering wheel shakes from left to right and you feel the vibration in the front of your car until you let go of the brakes.

The fact that you brake and go over a bump should first clue you in on the fact that it most likely is your ABS kicking in. It also will not stop until you release the brake because that is what is designed to do, the whole purpose is to prevent the brakes from locking up and causing an unsafe condition. It forces the driver to release the brake and re-engage the brakes which ensures that the brakes will not lock up because of the bumps in the road. I simply was trying to explain that it was either your rotors being warped or your ABS kicking in, not quite sure how that's destructive.

I don't understand when people post here looking for answers and then get offended when others offer answers.

Thank you norcal 528i for understanding the intentions of my reply.
I am sorry if I misinterpreted your reply, but it sounded a bit arrogant when I read it.

In regards to ABS, everything I have been taught (which had to undo my years of training without ABS) is that you are to stand on the brakes once ABS activates (there are plenty of publications that tell you this), which is not what we used to do when the tires started to lock up (which was to release pressure or pump the brakes to the point that lockup was averted). This is now contrary to what you are telling me to do, release the brakes so it can reset itself and reapply, which increases my braking distance.

I personally find the ABS system when activated over a bump unsafe in both the E39 and E38, and to require brake release by the operator to stop the car from doing it’s own unnecessary and uncoordinated dance a hazard in the fact that stopping distance is exaggerated rather than reduced and controlled.

I have felt the e39 actuate the ABS system when the ground is slick, and it is nothing like when a bump is hit and it actuates. Under “normal” conditions of activation, it works great.

My past cars when hitting bumps while braking have activated the ABS system, but never with such nervousness and sense of uncontrollability the E39 has, those other cars also self corrected themselves without hesitation or interaction of the driver (just constant pressure as they have taught us with ABS).

I am sorry, but while I firmly believe in ABS, the system in the e39 is flawed in its execution over bumpy roads. For some reason the system becomes confused and can not reset it self, but instead sends itself into a violent frenzy instead of a controlled response like it exhibits on slick (but smooth) surfaces. When this wild sensation occurs, it is usually on dry surfaces, but with a bump or two on one side of the car, such a condition is common and calls for a controlled response, not what the E39 demonstrates.

While I am not trying to get into a “contest” with you, I am surprised that you have not seen more controlled responses in ABS systems used in other cars, could it be that you have not driven any other cars other than a BMW (j/k)?

With all the other cars I have owned with ABS and the multitude of rental cars I have driven with ABS (and I certainly like to give the rentals the “breakfast, lunch, and dinner” treatment, with the adage, “don’t be gentile, it’s a rental” branded into my head), I have never seen a car with such nervousness when ABS is actuated due to a bump on “dry” pavement, based on this, I begin to question if the system really is right, since it supposed to improve safety, not decrease it (what I believe it does in this situation).

Based on the responses to the original post, and some of mine, I think others may be in my camp.

All in all, I think the ABS systems by other manufacturers offer a higher level of control and composure than the E39 and E38 due to the reaction of the system over bumps.

I am not flaming, just telling you my opinion of the system based on the years of driving experience that I have, both with and without ABS systems.
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Old 12-17-2004, 09:25 PM
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OK, so I feel I am an unfortunate expert with this subject.

First off, this is not ABS normal working. This is ABS malfuntioning if at all.

Anybody with this problem knows how an ABS feels like when it engages. This does not feel the same.

Believe me when I tell you, one month after buying my E39 this symptom surprised me when I came to a red light. I was about 40'-50' away, driving normal city speed. The car did not even slowed down. Right into the butt of the car that was standing at the red light. $3500 damage on my car. $1500 on his car.

Since then, almost 3 crashes into the rear end of cars in front of me.

Fact: it will usually happen in a slow speed. 3-5 mph. The vibration is much faster then the pulsating speed of ABS working correctly.

cure: replaced shocks and struts on front and rear ends. Replaced wheels from 16" to 17" two weeks later. Since then, sysmptom almost completely dissapeared.

I have a theory of exactly how this happens. but it is way too long to explain in writing. But it has to do with a "positive feedback loop" between wheel bouncing to the air, while abs activates at the wrong time, landing on the road just to bounce again and to activate abs again while in the air. It causes harmonic oscilation that will not stop because it continues to feed itsef infinitly.

Not ABS, you can stop a car with ABS activated.
Not wraped rotors. Wraped rotors vibrates the steering wheel in high speed braking.

This symptom, happends in slow speed. Vibrate the front wheels (bouncing), and the car will NOT stop.

Of course, anybody who did not experience this first hand will think we don't know what we are talking about and we don't know how ABS feels.

Hope it is a little more clear now.

Is that fairly describs what you guys experiencing?

Last edited by MatWiz; 12-19-2004 at 05:51 AM. Reason: typo
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  #25  
Old 12-17-2004, 10:51 PM
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E39spd E39spd is offline
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Matwiz, yes very similar, but car was able to stop (not well, but it did stop). Interesting explination. Only thing, both cars have sport package (so larger wheels) and one is very low milage, other is up there, both have it. I would agree on the feedback loop.
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Is braking over bumps bad for rotors? Plaz General BMW 25 08-23-2002 08:47 PM


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