tomcat

Starting at SITM this year I started getting this grinding sound up front. Comes and goes, but not during idle. I got new tires a couple of months ago so thought it was the tires. But I don't think it's the tires anymore.

I just passed 80K on the odom. Does this sound like the beginning of a torque tube failure? When do they start to fail? Or maybe wheel bearings?

85fortheDrive

Is the sound affected by turning the steering wheel at all? More common at a particular speed?

tomcat

I think I hear the grinding on the highway and don't really notice it at lower speeds.

Kinda hard to tell RE: turning. Sometimes it starts when when the road curves. But the sound will also come and go going straight.

Could my brakes be dragging?

Mrmerlin

check the wheel bearings and while your there move the backing plates around paying careful attention to see if a tiny stone falls out , usually what happens is a piece of tar/stone falls off the tire and gets caught/stuck to the inner backing plate and this will sometimes cause a grinding noise from rubbing on the inner part of the rotor, als check your brake pads make sure they are the same thickness on each side of the rotor. Also check the power steering fluid if its low this could cause the problem if it hasnt been changed/flushed out in a while , you might consider doing a flush on the power steering system, it could be the pump , check each of the accesories AC, ALT, AIR PUMP,PWR STEERING, this requires removing the belts, turn every pulley and see if they turn smooththen put belts on one at a time , start the engine and see if the noise returns. Also check the fans see if their is a wire harness, coolant hose, or AC line that might be rubbing on the fan

Charley B

John, you can pretty much rule out TT bearings. If sound is not there when not moving it's not the TT. The same kinda holds for the power steering. When these start making noise they will tend to make the noise to some degree all the time.
Stan's suggestion regarding the brakes is a good one. It will help narrow things down if when you hear the sound on the freeway you try a few variations such as shifting into neutral and letting off the gas and see if it continues. If yes it is probably wheel related such as bearings or brakes. If it stops it is probably transmission related or vibration from engine, exhaust or transmission.
You might also try slowly weaving within your lane and listening to hearif thenoise varies as you apply some G force from side to side.
Did you go to a bigger tire? Have you checked to make sure they aren't rubbing?

tomcat

I'll check the wheel bearings ,brakes, and PS fluid.

Thanks guys.

Hawkeyes

Brake pad thickness equal on both sides??? If one pad is wearing more than the other, does it need to be corrected and if so, how - rebuild the caliper?

Thanks,
hawkeyes

Charley B

yes.
Probably.

tomcat

I had some movement in the right front wheel. Tightened the wheel bearing nut a little but the sound it still there. PS fluid looked ok - changed last summer.

I originally said grinding noise but maybe it isn't quite a grinding noise. But it does come on when I turn the wheel. Now I'm thinking it's the tires again.

But I do have another question. The left front rotor has these brown spots on it. Looks like burn marks. And in the middle of the brown spots you can see random "veins." Are these cracks? I have the slotted rotors and don't have any braking problems other than an occasional vibration in the pedal that also comes and goes. Change to ate blue and bled right before SITM. I guess I should check to see if the rotor is warped.

Charley B

You don't say, but I assume you're moving when you turn the wheel and hear the noise. If you hear a noise when turning the wheel while at a stop, then the culprit is the power steering. Either low fluid or a bad pump. If it happens when your moving there are several possibilities but since you just put on tires I would eliminate that first. Pull the wheels and see if there are any shiny spots showing up adjacent to the circumference of the tires. Also spin the tires by hand and see if there is one that doesn't want to turn like the others. If so you may have a warped rotor or bad caliper on that wheel.
You might be having a problem with the bedding of your brake pads. Brown deposits and occasional vibrations sound like a build up of pad material. This really shouldn't happen in normal every day driving. How old are your pads?

tomcat

Pads are probably about 18 months (15K miles). Other side (of the car) was shiny and clean. I tried to bed them about a month ago using the specified procedure. Stops fine and much less vibration through the pedal.

Mrmerlin

their should be NO vibes through the pedal, if so it indicates a warped rotor, or possible an out of balance tire, if you see spots on the rotors it might be a good idea to put on a new set with new pads, make sure the pads are wearing evenly first, if not then you may be in for a caliper rebuild, this could be part of the problem a stuuck caliper over heating one of the rotors so a new set of rotors wont fix this till the calipers are looked at