ABS activated while turning and light braking (Z4MC)

Nirvana1381 · 03-31-2017, 01:37 PM

Hi Guys,

Something odd is happening and I need help figuring it out.

Here is the background:
I have a Z4MC with OEM brakes except for carbotech pads. The pads were replaced last year and have about 5000 miles on them. My rotors are a bit used and probably almost ready to be changed (I can feel a 1mm lip).
I just changed my rear tires a week ago, and not too long after that, my brake pad light came on. I know one of the brake pad sensor was installed improperly when they changed my pad and is now slightly rubbing on the rim according to my mechanic. I'm guessing this is the reason of the brake pad light coming on.

Here is my issue:
Ever since I've changed those tires, when I'm in a curve and pushing on the brakes, the ABS is triggered very easily. I never experienced that before and I feel this is not normal. This happens at medium brake pressure, turning left or right. In the straight line, ABS triggers with much much more brake pressure.
Any idea of what could cause this ?

The HACK · 03-31-2017, 04:18 PM

Normal.

Nirvana1381 · 03-31-2017, 05:03 PM

Hmm ok but what changed ? I mean I ran it in the canyons a week before and it did not do that at the same brake pressure. It does it really early in the pedal travel. Actually, in the 3 years I've had that car, it is the first time I feel that, and I can feel that on a daily basis.

The HACK · 03-31-2017, 05:08 PM

Quote:

Originally Posted by Nirvana1381

Hmm ok but what changed ?

Quote:

Originally Posted by Nirvana1381

I just changed my rear tires a week ago

There you go.

Nirvana1381 · 03-31-2017, 08:28 PM

How is that impacting traction for the worse ? Do you care to elaborate ? What do you think is actually happening ?

dc_wright · 03-31-2017, 09:08 PM

Quote:

Originally Posted by Nirvana1381

How is that impacting traction for the worse ? Do you care to elaborate ? What do you think is actually happening ?

What size tires did you install?

The HACK · 03-31-2017, 09:40 PM

Quote:

Originally Posted by Nirvana1381

How is that impacting traction for the worse ? Do you care to elaborate ? What do you think is actually happening ?

New tires comes with a layer of mold release. The first 500 miles or so, before the mold release agent wears off grip will be significantly compromised.

Fact is exacerbated by braking while turning, when weight is shifted up front and rear traction decreases.

This DSC goes crazy and pumps the brakes on one of the wheels trying to regain traction.

Nirvana1381 · 04-01-2017, 10:04 AM

Oh I see, so what you are saying is I should do a little burnout and call it a day right ? Haha.

Joking aside, that's kind of a safety issue to have that layer on new tires I think. For a minute I thought it could be a wheel speed sensing issue, the back tires being bigger than the front because of the difference is wear.

Finnegan · 04-01-2017, 05:08 PM

Quote:

Originally Posted by Nirvana1381

Oh I see, so what you are saying is I should do a little burnout and call it a day right ? Haha.

Joking aside, that's kind of a safety issue to have that layer on new tires I think. For a minute I thought it could be a wheel speed sensing issue, the back tires being bigger than the front because of the difference is wear.

It is indeed a safety issue with new tires. OEM manuals warn of the first 500 miles, etc. with new cars. Just drive off the crap and you'll be back in business. "Honey, gonna be gone awhile, I have to drive the 'new tire molding compound' off the tires." See, it's a feature, not a bug!

elerner61 · 04-03-2017, 10:48 AM

Years ago I was in a local enthusiast tire center having some work done (fantastic place, ONLY did wheels and tires, nothing else). Was chatting with the owner while paying and he told me earlier in the day he had warned a youngish owner of a 911 to be careful about the mold release. Mr. 911 proceeded to do a massive burnout in the parking lot on his exit.

ShakyDog · 04-03-2017, 11:24 AM

That and are the tires the same, other than size front and rear? I have read this will cause the issues also.

Steve

Nirvana1381 · 05-02-2017, 03:05 PM

Tires are indeed the same, yes. Conti Extreme Contact DW.

Finnegan · 05-02-2017, 03:44 PM

Quote:

Originally Posted by Nirvana1381

Tires are indeed the same, yes. Conti Extreme Contact DW.

Have you put 500 miles on these? Any change?

If not, and +500 miles added, is the aspect ratio or width, different than what you had previously?

Did you have any alignment work done (changes in toe, camber) when the tires were installed?

mattr88 · 05-31-2017, 09:56 AM

I am having the same issue with my 2005 E85, it is not an M, but has the M Sport suspension. I thought it was tire related, but replaced the tires back in February and have put on well over 500 miles on the tires. Tire sizes are the same, I moved from the Michelin Pilot Sport A/S 3 to the Pilot Super Sports in the same tire size and the issue still exists. I am thinking it is not tire related given I am having the exact same symptoms as before. I have had an alignment done, bled the breaks, rotors and pads are fine, but still see the issue.

03-31-2017, 01:37 PM	#1
Nirvana1381 New Member 3 Rep 12 Posts Drives: Z4 M Coupe Join Date: Sep 2016 Location: California iTrader: (0)	ABS activated while turning and light braking (Z4MC) Hi Guys, Something odd is happening and I need help figuring it out. Here is the background: I have a Z4MC with OEM brakes except for carbotech pads. The pads were replaced last year and have about 5000 miles on them. My rotors are a bit used and probably almost ready to be changed (I can feel a 1mm lip). I just changed my rear tires a week ago, and not too long after that, my brake pad light came on. I know one of the brake pad sensor was installed improperly when they changed my pad and is now slightly rubbing on the rim according to my mechanic. I'm guessing this is the reason of the brake pad light coming on. Here is my issue: Ever since I've changed those tires, when I'm in a curve and pushing on the brakes, the ABS is triggered very easily. I never experienced that before and I feel this is not normal. This happens at medium brake pressure, turning left or right. In the straight line, ABS triggers with much much more brake pressure. Any idea of what could cause this ?
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03-31-2017, 04:18 PM	#2
The HACK Midlife Crises Racing Silent but Deadly Class 1820 Rep 5,337 Posts Drives: 2006 MZ4C, 2021 Tesla Model 3 Join Date: Oct 2007 Location: Welcome to Jamaica have a nice day iTrader: (1)	Normal. __________________ Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
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03-31-2017, 05:03 PM	#3
Nirvana1381 New Member 3 Rep 12 Posts Drives: Z4 M Coupe Join Date: Sep 2016 Location: California iTrader: (0)	Hmm ok but what changed ? I mean I ran it in the canyons a week before and it did not do that at the same brake pressure. It does it really early in the pedal travel. Actually, in the 3 years I've had that car, it is the first time I feel that, and I can feel that on a daily basis.
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03-31-2017, 08:28 PM	#5
Nirvana1381 New Member 3 Rep 12 Posts Drives: Z4 M Coupe Join Date: Sep 2016 Location: California iTrader: (0)	How is that impacting traction for the worse ? Do you care to elaborate ? What do you think is actually happening ?
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04-01-2017, 10:04 AM	#8
Nirvana1381 New Member 3 Rep 12 Posts Drives: Z4 M Coupe Join Date: Sep 2016 Location: California iTrader: (0)	Oh I see, so what you are saying is I should do a little burnout and call it a day right ? Haha. Joking aside, that's kind of a safety issue to have that layer on new tires I think. For a minute I thought it could be a wheel speed sensing issue, the back tires being bigger than the front because of the difference is wear.
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04-03-2017, 10:48 AM	#10
elerner61 Major 157 Rep 1,107 Posts Drives: '07 Z4M Roadster Join Date: May 2011 Location: Mount Kisco, NY iTrader: (0)	Years ago I was in a local enthusiast tire center having some work done (fantastic place, ONLY did wheels and tires, nothing else). Was chatting with the owner while paying and he told me earlier in the day he had warned a youngish owner of a 911 to be careful about the mold release. Mr. 911 proceeded to do a massive burnout in the parking lot on his exit.
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04-03-2017, 11:24 AM	#11
ShakyDog Captain 181 Rep 623 Posts Drives: 2007 Z4 3.0i Alpine White/Red Join Date: Mar 2010 Location: Missouri iTrader: (4)	That and are the tires the same, other than size front and rear? I have read this will cause the issues also. Steve
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05-02-2017, 03:05 PM	#12
Nirvana1381 New Member 3 Rep 12 Posts Drives: Z4 M Coupe Join Date: Sep 2016 Location: California iTrader: (0)	Tires are indeed the same, yes. Conti Extreme Contact DW.
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05-31-2017, 09:56 AM	#14
mattr88 New Member 0 Rep 23 Posts Drives: 2005 Z4 3.0i Join Date: Aug 2013 Location: Bay Area, California iTrader: (0)	I am having the same issue with my 2005 E85, it is not an M, but has the M Sport suspension. I thought it was tire related, but replaced the tires back in February and have put on well over 500 miles on the tires. Tire sizes are the same, I moved from the Michelin Pilot Sport A/S 3 to the Pilot Super Sports in the same tire size and the issue still exists. I am thinking it is not tire related given I am having the exact same symptoms as before. I have had an alignment done, bled the breaks, rotors and pads are fine, but still see the issue.
	Appreciate 0 Quote