Machanical Noise When Coming To A Hard Stop

[justflyin83]

I recently purchased a 2006 IS350 with 39,000 miles on it. I previously had a 2008 IS250 AWD that I was leasing. I noticed that when coming to an extremely hard stop, right before the threshold of locking up the brakes my car makes some sort of mechanical noise, almost sounds like an electric motor that runs for a second when the car reaches a complete stop. I tested this out several times and it does it everytime I come to a very hard stop. I'm assuming it has something to do with the ABS but the ABS is not kicking in, nor should it as i'm not locking up the wheels.

Any idea on what this is? And is it normal?

[smooth1]

I recently purchased a 2006 IS350 with 39,000 miles on it. I previously had a 2008 IS250 AWD that I was leasing. I noticed that when coming to an extremely hard stop, right before the threshold of locking up the brakes my car makes some sort of mechanical noise, almost sounds like an electric motor that runs for a second when the car reaches a complete stop. I tested this out several times and it does it everytime I come to a very hard stop. I'm assuming it has something to do with the ABS but the ABS is not kicking in, nor should it as i'm not locking up the wheels.

Any idea on what this is? And is it normal?

Yep, it's normal.

[NicLX470]

I recently purchased a 2006 IS350 with 39,000 miles on it. I previously had a 2008 IS250 AWD that I was leasing. I noticed that when coming to an extremely hard stop, right before the threshold of locking up the brakes my car makes some sort of mechanical noise, almost sounds like an electric motor that runs for a second when the car reaches a complete stop. I tested this out several times and it does it everytime I come to a very hard stop. I'm assuming it has something to do with the ABS but the ABS is not kicking in, nor should it as i'm not locking up the wheels.

Any idea on what this is? And is it normal?

It is the ABS. It is doing the right thing by NOT locking up the wheels. If they locked up then it would not be working right. At the moment you hear the motor noise is when the wheels would "lock up" on a non-ABS car.

[Sidney07]

ABS can sound disconcerting the first time you hear it. Totally normal tho....every car I've had with ABS will make that noise.

[CrunchySkippy]

The ABS noise is usually accompanied by brake pedal vibration (think foot massage).

Although it is unusual that you never experienced this with your previous IS250 (or any other vehicle with ABS for that matter), it sounds like a textbook description of the ABS.

[justflyin83]

Well that's the thing, I know exaclty what ABS is. I came from a 2008 IS250 and before that I had a 2005 Evolution VIII. The noise is just that, a noise. The ABS is not kicking in as i'm not slamming on the brakes. If the car didn't have ABS it would not lock up the brakes during the same type of stopping. The pulsation of the pedal (or grinding feel in the pedal) is not there as i'm not trying to slam on the brakes.

It happens when I come to a very quick/hard stop, the type of stop that will bring you from 60-0 in the fastest way possible without trying to come to sliding stop. Once you feel the car reaches the stop you hear a motor sound run for 1-2 seconds and then it's gone. In no way is the antilock braking system activating or even trying to.

[justflyin83]

Keep in mind that the noise begins and ends (1-2 seconds) once the car has already reached a stop.

[Sidney07]

OK...you hear a "motor sound"? I've never heard of such a thing, especially after you stop. RPMs at idle the whole time?

I'm stumped. Which isn't really to hard to do.

[CrunchySkippy]

Perhaps it is an electrical pump that your hearing. Although I have no idea why it would cycle a few seconds after stopping (and not be running constantly).

Do you recall if you had a near-empty gas tank? I'm thinking maybe your fuel was sloshing to the front of the gas tank under hard deceleration and away from the pickup. Once the fuel levels out again, the pump has to "re-prime" to purge any air it may have picked up during the absence of fuel.

May as well go ahead and check all your fluids (if you buy into my far reaching electrical pump theory). Brake Fluid, Power Steering Fluid, even Windshield Washer Fluid. Or anything else that is powered by a pump (or sorts).

[justflyin83]

Yeah it's weird. It leads me to still believe it has something to do with the ABS. The reason is if I come to a quick stop but not as hard, the sound will not be activated. I literally have to come to the almost the hardest stop possible, the next hardest would be me pushing the brake pedal to the floor as hard as I could.