strange noise after some recent work

majidmo · #1 11-13-2012, 04:08 PM

Hi guys,
I need help with a new problem. X5 is 2003 3.0 and has 109 K miles on it. I recently changed tires, brakes, Thermostat, drive belts A/C and Alternator belt and valve cover gasket and had a 4-Wheel alignment done (most of them at the dealer). After that I noticed a strange sound while driving (listen to attachment). It starts when I take my feet off of gas pedal and appears it goes away as soon as I press gas pedal. No vibration. I don't hear it while car is idling.

Any idea what it is or where to start?

Thanks in advance.

Sponsored Links

TerminatorX5 · #2 11-13-2012, 11:41 PM

i listened to the sound, even though it sounded muffled... you were driving, at a slow speed, (about 30-40 MPH?), and had this sound... did the sound come from the front, back, left or right? i assume you had your windows down when you recorded the sound... the frequency of the beat sound as if something stuck to a tire and beats on the road as thhe tire is rotating, as the timing between each beat as if it is approximately the time for a tire to make a full rotation. once the speed of the car increases, the beats happened more often, as tire rotates faster, and to a human ear the beats blend into one, solid humming noise... I do not suspect the engine components as the rotational speed of the engine is much faster in hundres of rotations per second... not to discount the possibility of a beating timing chain but I don't know if the timing chain is prone to failure on the I-6 engines...
you mentioned that you changed brakes - was everything secured properly? you say tires were replaced but since there is no vibration, it is probably not a flat spot on the tire... another thing could be, a balancing weight on a wheel is rubbing against the brake assembly...

drive by a wall (like a sound wall on a highway), with window open, and listen to the sound.. try to drive fast, and slow, to see of the rotational frequency coinsides with the speed of the car, while driving slow and listening to the noise, rev the engine in neutral, to see if the noise will pick up or stay the same - if it picks up with the engine, something in the engine, if stays the same with the spedd of the car, then it is in the tires/wheels/brakes...

majidmo · #3 11-14-2012, 04:28 PM

Quote:

Originally Posted by TerminatorX5

i listened to the sound, even though it sounded muffled... you were driving, at a slow speed, (about 30-40 MPH?), and had this sound... did the sound come from the front, back, left or right? i assume you had your windows down when you recorded the sound... the frequency of the beat sound as if something stuck to a tire and beats on the road as thhe tire is rotating, as the timing between each beat as if it is approximately the time for a tire to make a full rotation. once the speed of the car increases, the beats happened more often, as tire rotates faster, and to a human ear the beats blend into one, solid humming noise... I do not suspect the engine components as the rotational speed of the engine is much faster in hundres of rotations per second... not to discount the possibility of a beating timing chain but I don't know if the timing chain is prone to failure on the I-6 engines...
you mentioned that you changed brakes - was everything secured properly? you say tires were replaced but since there is no vibration, it is probably not a flat spot on the tire... another thing could be, a balancing weight on a wheel is rubbing against the brake assembly...

drive by a wall (like a sound wall on a highway), with window open, and listen to the sound.. try to drive fast, and slow, to see of the rotational frequency coinsides with the speed of the car, while driving slow and listening to the noise, rev the engine in neutral, to see if the noise will pick up or stay the same - if it picks up with the engine, something in the engine, if stays the same with the spedd of the car, then it is in the tires/wheels/brakes...

Yes. It sounds like having a flat tire. I will take the wheels off today and check the brakes. It could be the sensor not being secure in place. I will report back. Thanks for giving me some ideas.

majidmo · #4 11-15-2012, 06:07 PM

I put jack under the car and then went to get log nuts loose on the passenger side wheel and guess what. 4 of the 5 log nuts where completely loose and I could turn them with my fingers. Surprised they didn't fall out. I think I forgot to torque them when I moved to work on the other wheel.
Strange that dealer didn't notice it when doing the alignment. Wouldn't wheel being so loose throw off the alignment?

TerminatorX5 · #5 11-15-2012, 08:37 PM

i don't know about the alighnmnet...

but, i am embarassed to admit, once, when i changed the wheels to the winter setup in Moscow, i had some handling issues along with the noise coming from the front left... as i came to my destination, and parked the car, i went around, looking for an issue, did not see anything but tried the lug bolts - sure enough, the front left were half way out!!! I tightened them up, and went around the car, making sure the other ones were ok... Major safety issue, due to my personal neglect!!!

Since then, I double make sure the lugs are tight, and when i take a car on a short errand, I re-tighten the lugs once more - just to be on the safe side...

I am glad you have resolved the issue

Sponsored Links