Grinding noise from the front

2004 Chevrolet Impala (9C1 ex-police, naturally aspirated, 85000 miles)

I'm getting a strange grinding noise (sounds like scraping a rock across the ground) from the front end of the car. This noise starts happening a few minutes after driving the car. The longer you drive it, the more frequently it starts occurring. Also, it only happens when the car is in the 13-18 mph speed range and only when the car is slowing down (braking or coasting), never when accelerating (gas pedal or downhill) through that speed range.

The car had this problem when I bought it at 82000 miles and I thought that it was an issue with the front brakes. I replaced the rotors and the brake pads. Also, there seems to be no play in the front wheel hubs. I'm out of ideas at the moment. Any help would be appreciated. Thank you.

See if you can pinpoint this ft wheels off the ground car in gear, use proper safety techniques of course.

2004 Chevrolet Impala (9C1 ex-police, naturally aspirated, 85000 miles)

I'm getting a strange grinding noise (sounds like scraping a rock across the ground) from the front end of the car. This noise starts happening a few minutes after driving the car. The longer you drive it, the more frequently it starts occurring. Also, it only happens when the car is in the 13-18 mph speed range and only when the car is slowing down (braking or coasting), never when accelerating (gas pedal or downhill) through that speed range.

The car had this problem when I bought it at 82000 miles and I thought that it was an issue with the front brakes. I replaced the rotors and the brake pads. Also, there seems to be no play in the front wheel hubs. I'm out of ideas at the moment. Any help would be appreciated. Thank you.

check all the plastic in the wheel wells for security...these plastic fasteners wear out then the plastic panels wander into the tires...

See if you can pinpoint this ft wheels off the ground car in gear, use proper safety techniques of course.

Outside of placing the car jacks under car's frame front frame, setting the parking brake, and placing chocks behind the back wheels, is there anything else I should be doing? I won't have a chance to do this until the weekend... I will let you know how it goes.

check all the plastic in the wheel wells for security...these plastic fasteners wear out then the plastic panels wander into the tires...

I'll check out the wheel wells this evening. However, I don't think that this would explain why the noise occurs only at certain speeds and only when the car is slowing down...

I'll check out the wheel wells this evening. However, I don't think that this would explain why the noise occurs only at certain speeds and only when the car is slowing down...

at a certain speed the plastic will flex out of position by air forces then when braking the front end dips slightly....this can be an interference problem....

at a certain speed the plastic will flex out of position by air forces then when braking the front end dips slightly....this can be an interference problem....

I checked the wheel wells and there is nothing that I can see that could be scraping against the tires... I considered the possibility that air might be flexing some plastic in the area out of position but it doesn't explain why the noise doesn't happen in the first few minutes of driving the car and then starts happening more often the longer the car is driven. If some plastic was being bent out of position, I would think that you would also get this type of noise at higher speeds and when braking more aggressively.


The only plastic near the wheel wells that has any potential of touching the ground or the tires would be the splash guards, and I highly doubt that they are the problem. They're made out of some type of plastic that's not all that flexible, and I highly doubt that air forces would bend them forward towards the front tires, considering that they're placed behind the front wheel wells.

[quote=sarotara]I checked the wheel wells and there is nothing that I can see that could be scraping against the tires... I considered the possibility that air might be flexing some plastic in the area out of position but it doesn't explain why the noise doesn't happen in the first few minutes of driving the car and then starts happening more often the longer the car is driven. If some plastic was being bent out of position, I would think that you would also get this type of noise at higher speeds and when braking more aggressively.


as the engine gets hot the plastic gets softer....grab on to plastic don't just LOOK at it,,,, see if it can move into the tire area...


the plastic pins that secure the panels are defective and wear out..


look and move the panels inside the engine compartment for inteference with the engine belt pulleys etc...

Double checked the wheel well areas for interference with tires... There is nothing in there that I can see that could potentially scrap up against the tires.

heres a long shot ... does your car have speed sensors on the front hubs ? if so maybe one of them might have got jard durring a pursuit ? and causing your noise ??

also you said you replaced the front rotors ? did you also replace the wheel bearings and seal ?

also you said you replaced the front rotors ? did you also replace the wheel bearings and seal ?

Nope, replaced just the rotors and the pads.

heres a long shot ... does your car have speed sensors on the front hubs ? if so maybe one of them might have got jard durring a pursuit ? and causing your noise ??

I don't believe that the front hubs have speed sensors... I could be wrong however. Here are the pictures from the front pad and rotor replacement.

http://ornus.org/images/impala_2004_front_rotors_pads/

you may want to inspect and replace the bearings and seals ? and make sure you get a proper preload on the bearings .

ok i see you have a two piece hub and rotor ? and if im correct those bearings are sealed . i had a beretta with the same annoying symptoms and it was the bearings .,,,,,,,,,,,, good luck and let me know?

if possible could you send me a pic of the back side of the hub ?i wanna see if theres a speed sensor or a abs sensor

if possible could you send me a pic of the back side of the hub ?i wanna see if theres a speed sensor or a abs sensor

http://ornus.org/images/2004_impala_front_wheel_left_rear/

Here is the best I can do without taking the tire and rotor off. I can take the tire off sometime tomorrow and get better pictures then. Looking in the manual, it turns out that some Impala models have the speed sensor but other do not. I think that the plastic-shrouded cable would be the wheel speed sensor electrical connector...

I don't believe that the front hubs have speed sensors... I could be wrong however. Here are the pictures from the front pad and rotor replacement.

http://ornus.org/images/impala_2004_front_rotors_pads/


the scraping noise how does it sound ...metal to metal constant tone or does it vary in pitch etc..?

the scraping noise how does it sound ...metal to metal constant tone or does it vary in pitch etc..?

It sounds like scraping a stone across the pavement. There isn't that much variation in pitch.

im almost willing to bet you have a bad bearing ? i also noticed on one of the first pics you sent it appears to have oil of some type around the axle nut , that would tell me one of those sealed bearings is leaking its juice out ? haha, take your car to a tire shop , they can tell you if its a bearing or not ,and thanks for the pics ,,, they helped

im almost willing to bet you have a bad bearing ? i also noticed on one of the first pics you sent it appears to have oil of some type around the axle nut , that would tell me one of those sealed bearings is leaking its juice out ? haha, take your car to a tire shop , they can tell you if its a bearing or not ,and thanks for the pics ,,, they helped


It is possible that it's a bearing BUT how many thousand miles and its still not totally gone?????? this is odd.....once a bearing starts to make noise 2,000 mi is all you can get...

how about front brake heat shields...

im almost willing to bet you have a bad bearing ? i also noticed on one of the first pics you sent it appears to have oil of some type around the axle nut , that would tell me one of those sealed bearings is leaking its juice out ? haha, take your car to a tire shop , they can tell you if its a bearing or not ,and thanks for the pics ,,, they helped

I'll remove the tires and rotors tomorrow or next weekend and take a look at the wheel hub more closely... At least the front ones are cheaper than the rear ones. Thanks for the help. I'll let you know what I find

It is possible that it's a bearing BUT how many thousand miles and its still not totally gone?????? this is odd.....once a bearing starts to make noise 2,000 mi is all you can get...

how about front brake heat shields...


This problem was already there when I bought the car when it had 82k miles. I thought it was an issue with the front brakes. I was wrong. The car now has over 86k miles and the problem hasn't gotten worse. Front brake heat shield = wheel bearing hub splash shield? That wouldn't explain why the noise only happens at a certain speed range and only in certain situations...The splash shield mounts between the wheel bearing hub and the steering knuckle. No chance for it to move anywhere unless the whole wheel bearing assembly was loose, and I'm pretty positive that it's not.

check those antirattle clips on either side of the pads they move easily could be slightly touching the rotor on slight turns or during light brake application.they also require a little silguilde or caliper grease to let the pads slide and release with ease. let me know. if nothing there look closely inside the back of wheel to see if there are any signs of rubbing.

check those antirattle clips on either side of the pads they move easily could be slightly touching the rotor on slight turns or during light brake application.they also require a little silguilde or caliper grease to let the pads slide and release with ease. let me know. if nothing there look closely inside the back of wheel to see if there are any signs of rubbing.

I initially thought so too, but after replacing the pads and rotors I went back and put new clips in and lubricated them. I also thought that it might have been the caliper pistons sticking, but the noise happens regardless of whether I'm braking or not. When the car is slowing down (brakes or just coasting) through the 13-18 mph speed range I get grinding from the front end. Whether the car is turning or going straight makes no difference.

well this is just a thought but the wheels arent the only spinning thing make sure there is nothing rubbing the axles. oh and if there any doubts about the clip thing you could remove them and take it for a short ride

well this is just a thought but the wheels arent the only spinning thing make sure there is nothing rubbing the axles. oh and if there any doubts about the clip thing you could remove them and take it for a short ride

Nothing rubbing against the axle that I can see. I removed some of the plastic panels near the wheels/axle, but the noise is still there.

Hi guys, new to the forum, ...The '04 police equipped impala has an adapter for an additional oil cooler. It moves the oil filter assembly closer to the passenger side inner CV boot. The band that holds the boot on has a crimp that protrudes slightly. Normally there is sufficient clearance but if the car has had even minor front end damage or the motor mounts become worn you have elusive intermittent contact aka clicking/ scraping. Remember that steering moves the half shift forward and back ever so slightly as well.

A/C compressor will make the same noise with a/c off- are you sure it is not that..?