Hello to all that stumble upon this thread. I drive a ‘05 MCS w/ a 6 speed manny tranny, and w/ 128,xxx miles. The issue is a squealing noise that occurs when I’am driving below 30 mph. Only at that speed does the annoyance occur. Anyone have a clue, or can declare where the issue is coming from before I swap this, and swap that, and the noise persist to lurk.

 

Usually squeeling would be belt related. So I would check there first, belt condition, shiny belt will cause squeel. Pulleys siezed of not in line with each other.

Without a bit more specific info its hard, could be brake pads worn down, whole number of things.

Could do with knowing things like,
front of back
Left or right
Any other noises going on

 

A video for the sound could also be pretty helpful

 

It is not the belt. I’am certain about that. This squealing noise sounds like it if were the brakes, but I had replaced them. Front, and rear along w/ front, and rear rotors. I hear the sound coming from the front side of the vehicle, but like any noise it may come from the rear ? Like I mentioned. The sound only occurs when I’am driving at a low speed. Exactly 25 mph, or below.

 

Could be the idler pulley. Or, since you recently replaced the brakes did you use anti-squeal on the pad backs?

 

Wheel bearing

 

I did not use anti squeal, but some brake lubricant on the back side of the pads to absorb vibration. Excuse my ignorance cooper48, but may you explain to me more about the idler pulley in how it can be a source to this squealing noise my turtle has developed ? DFTR I had conceived the notion that it has to be a wheel bearing. I’am going to inspect any abnormal motion on the tires to detect which one ? Thanks for all of your replies, and suggestions. I’ll update for any solutions. O, cooper48. Don’t forget to educate me on that thought of yours. Keep motoring !

 

The idler pulley helps maintain tension on the serpentine belt. It has a bearing in the center that can fail and create noise/squeal. The best method to check for this is to remove the serpentine belt and turn the idler pulley by hand. If it is faulty it will either wobble or make noise. It's affixed by a single bolt through the center and the pulley is easy to replace. It's number 3 in this link: https://www.realoem.com/bmw/enUS/sho...diagId=11_3394

 

Does it relate to engine speed or wheel speed?

 

Wheel speed.

 

ok. I’d say it’s bearing or brakes then

does sound change or go away when you apply brakes?

get up to speed where noise is present, then apply brakes lightly, w left foot, keeping speed constant with right foot on throttle…

 

The noise stops when I apply the brakes. Like I mentioned before. I’ve replaced front, and rear brake pads, and rotors.. But I’ll try your method, and go from there. Thanks. I’ll give a solution soon, or later.

 

New retainer clip thingy for the brake pads might help

 

Try pulling the handbrake up a click when it's making noise, if it stops it's probably the retaining spring on them, if it still makes noise look at the front

 

It could be some glazing on the brake pad. Take them off and do some light sanding.