I've had this happen on two occasions now and on the same windy mountain road (coincidence?). I was doing some light braking and there was a very quick grinding noise that could be felt in the brake pedal. Could this be an ABS issue? Did anyone else ever experience this?

Just as an extra piece of info, the car has new front rotors and pads. I recently also had both front axles refurbished but the first time this happened was before that so it can't be CV joint related.

Any ideas? I've tried to replicate the problem but can't; it only seems to happen on a very rare occasion. Anyway, just trying to figure out what it could be if there is actually a problem.

 

Depending upon how aggressively you were driving this mountain road, it could well be your abs kickin in.
I never hear any "grinding" per se, but if you are relatively new to this car, it's takes a minute to get used to the abs/psm since it activates in situations that have to do seemingly with momentary loss of traction that could be as simple as a bump in the road of a sweeper, at speed. I get abs activation all the time, the way i drive in canyons. Clearly, I'm no expert but it did take me awhile to get used to the "pulse" of our abs/psm system.

If there is no discernible "grinding" but it's simply the pulse of activation, you're just on the learning curve, and driving the car as it should be driven.

 

Thanks for the response! Since you are getting it too, maybe it is not that uncommon. The main reason I'm thinking ABS is because it was a very similar feel in the brake pedal. Never get this on my other cars unless I absolutely slam the brakes (as in an emergency stop) but I also never owned an AWD sports car, so I'm not used to traction control in the front.

I'll monitor it for now. I figured I would feel or hear it more if it were the differential. CV joints are in great shape, so that really only leaves the brakes...

 

Pretty sure I was on the top of a minor bump/hill just in a turn, so you may be right on the money. This traction control must be pretty intrusive because I was driving at a nice pace but not overly aggressive by any means.

 

it's very intrusive and yet, the other side of that is i'm fairly sure it saved me once at high speeds from someone that didn't know i was driving too fast to deal with their entering into my equation i was sideways, for real. i'm a fan of psm/abs actually, but not under conditions you described. eg fast canyons and bumps!

again, i think you're "learning" this car, and i'm glad you're finding its limits. that's where the fun lives.

 

Traction control on the street can definitely be a good thing

On my BMW, it's pretty basic and just cuts the power, so it never really slows you down, it just prevents you from spinning the tires coming out of a corner.

 

i only get common problems. but i do get them consistently.

 

funny you mention that. i remember my abs on my last 335 as having a similar but more more "quick" acting response. i.e. faster on/off than my porsche's.

but then as good a handler as the 335 was, it never got me into situations that these cars can, with daily regularity

don't get me wrong. the 335i is still to me, the best daily driver i've had. even if i had trouble getting abs to activate

 

My older BMW has ASC, which is pretty primitive; it just cuts the power to the real wheels. ABS itself really only comes on when you slam the brakes in an emergency stop but never as traction control while driving.

 

whatever that orange light was. i never felt as if it was doing anything! it just blinked. in these cars, it blinks with emphasis.. but you already knew that

 

I just read up on PSM a bit. Definitely a lot more advanced than other cars! I actually do not remember if any lights were flashing (too focused on the road ) but very possible I experienced the PSM intervening and applying some braking to one of the front wheels; just seemed a bit too intrusive.