Several times now when I'm applying the brakes when approaching an intersection (stop sign/traffic light), the brake pedal literally "stutters" and I lose some pedal firmness. If I have to suddenly stop, there hasn't been any similar symptom...yet. The symptom only seems to appear occasionally...but when it happens, it GRABS my attention. Help!
Have you done anything to the brakes recently? *thought* there may have been some posts about pad/rotor changes
ABS kicking in briefly on a loose surface? A bit of sand or gravel can cause that. If you recently have had brake work done have it checked out. ASAP!
1. Brake pads, lines, & rotors were replaced on 04/16. No problems at all until yesterday morning. 2. Residential streets are smooth, as are the highway miles. No gravel or dirt. 3. Had to replace driver front wheel speed sensor on 04/23 after it died on 04/19. 4. Dashboard light trifecta (ABS/tire pressure/DSC) came on this morning, but only after the "brake pedal stutter" happened 2x. The lights disappeared and haven't come back on. 5. I do have a "rotational rubbing" sound that doesn't seem to kick in until I'm over 20mph...it gets progressively louder the faster I go. Will someplace like Autozone, Advance Auto Parts, or NAPA have a code reader that will tell me what's going on?
Well you should not be seeing a light or hearing a sound. I think you need to pull the wheel & have a look see. Not sure if autozone can read your code. Even if they can it is doubtful they will know what the code means.
Scott may be on to something. If the wiring is not routed correctly it can foul moving parts. Another possibility is that the plug wasn't pushed together correctly & had come undone or has an intermittent connection.
Here's the process I used for replacing the Wheel Speed Sensor after I exposed the work area: 1. Unclipped the blue connector. 2. Unclipped the rubberized "zipties" between the blue connector and the coilover, but didn't remove the piece that is attached to the coilover. 3. Plugged in the new blue connector. 4. Clipped the rubberized zipties between the blue connector and the coilover. 5. Pulled the old piece from the coilover and unclipped the remaining rubberized zipties. 6. Installed the new piece to the coilover, but left the rest of the new sensor dangling. 7. Used an allen wrench to remove the sensor that was attached to the back of the rotor. 8. Installed the new connector and then clipped the rubberized zipties. Reinstalled the wheel liner cover & wheel and then took a nap.
I agree with Scott, it sounds like one of your wheel speed sensors is toast. Bring it to a dealer or BMW mechanic with a scan tool that can read wheel speed sensors and they can tell you which one's bad. I wonder if you could isolate the ABS system by pulling the fuse and then doing a few brake tests. If the car brakes fine, you know it's just the wheel speed sensor.
No, not off the top of my head. But it should have a picture of a circle surrounding the letters "ABS". I was chasing down the fuse for the fuel pump this weekend. It was wrong in the Bentley (F20, nope), it was wrong in a 2003 post on the sewing site (R4? nope), and I just about gave up until I saw the icon that looks like the one next to the gas gauge - a fuel pump (F38, I believe). My takeaway was that you're better off just looking for the pictures. Stole this from NAM:
I know you put on new brakes but it sounds like a warped rotor or one that is out of round. If you have a mounted rotors onto dirty wheel hub, rotors will not run concentric.
If the rotor had been mounted incorrectly or was out-of-round, wouldn't the rotational noise have started much sooner vs. just over a week later?
Hey Erika, did you ever get this sorted out? I meant to introduce myself on the HRMINIs caravan to MOTD, but my timing was off.
Me, too! I'm glad that Helix was able to diagnose & do the repair at MOTD...big thanks to Way for being able to bring the bearing up on Friday. I did get to make a few runs on the Dragon, but I spent most of MOTD observing vs. driving. While Schultze was "down", Troy from Dent Tricks did an AWESOME job of removing all the dings & dents...including the one on near my boot emblem. I plan on doing a run up to Virginia's BOTD next weekend: | Back of the Dragon: Virginia!