Rotor warped? or not?

[rszappa1]

I have found that if you have warped rotors and have them turned...the pulsing will come back again...

 

[mstrjon32]

Rotors that have been cut are more prone to warping than those that are new. So if you're warping new rotors, you're going to warp cut rotors faster.

Typically when I have a warped rotor problem, it usually comes with a set of ceramic pads. Changing to semi-metallic pads usually does the trick.

 

[oilyriser]

I sand my rotors if I start to feel any pulsation and a special driving technique doesn't fix it.

 

[mechtech2]

The mounting surface and inner and outer hub of the rotor must be corrosion free. A little grease is a good idea.
Once they have been disturbed after taking a 'set' by seating and corroding together, they should be checked and re-cleaned, as you have found out.

 

[spyghost]

i am experiencing a humming sound between 40kph and 50kph regardless of the engine rpm and transmission gear. outside those boundaries, there are no humming sounds. just to give a brief overview, this is a 2000 mitsubishi lancer all stock at 75000 km. the rotors haven't been resurfaced since it was bought first hand in march 2000 and it is still the same rotor. as for the suspension components, they are still in good condition. shocks are new as well as the strut mounts. nuts are torqued to factory specs, bushings are good, and wheels are aligned.

if it were a wheel bearing, then the wound would be going faster, right? but it doesn't. the humming stops beyond 50 kph.

i lifted my front, removed the wheels and turned the axle by hand through the studs. there are some portions of the turn that i feel some slight grinding. that area appears to be on the same portion no matter how i turn the wheels (cc, or ccw; fast or slow).

could this be the cause of the humming sound that i hear? is there any other way of isolating which is the cause of the sound (bearing, rotor, pads, or caliper)? what can i do to eliminate this?

there are no drivability problems, its just that its really annoying and it might be a cause of another possible problem

 

[oilyriser]

My Subaru has one imperfect wheel bearing, and the hum from it becomes noticeable only at certain speeds. Fortunately it hasn't gotten any worse after 130,000 miles.

 

[rpn453]

Originally Posted By: rpn453
Maybe the cheap pads were depositing material on the rotor and causing that feeling? I don't drive it often enough to say anything for sure, but I'll take it for a spin next time I get a chance.


Scrap that theory. I took it for a drive and they feel warped again.