There will be a pulsating on braking.
if you are driving and you go to stop, then that means that the front rotors are warped. if the front rotors are bad, you will feel a pulsation in pedal while applying brakes. change rotors on front.
as long is they are not dug into the rotor its normal after driving to get lines or marks on the rotors and drums
Warped rotors. Driving using the left foot to brake causes the rotors to heat up. Quenching the hot rotors by driving thru water will cause them to warp. The warped rotors cause the pedal to pulsate.
The drive belt may be slipping or going bad.
There is a pulsating on braking.
Yep.
Grinding
Either warped rotors or drums can cause pulsating. Apply the parking brake slowly while going about 15mph and see if t pulsates. If it does, it is the drums that need turning. If not, it is the rotors that need turning.
Most IS 250s, depending on driving, get about 25000-30000 miles on the front brakes and rotors.
could be bad rotors, or brake pads wearing unevenly, which would result in bad rotors.
It could be several things. I'll start with the obvious. Warped or badly worn brake rotors, bad tires, bent suspension components.
There could be a belt broken in one of the tires. The rotors may also need turned or even replaced.