Hey Guys,

I have a 2004 Mini Cooper S with 111,000 miles on it. I was driving on the expressway on the way home when I noticed a whine/rattle coming form the engine compartment. There is no check engine light and the car/engine still seems to runs fine. I was able to drive home which was another 5 miles away.

I took a video of it and posted to youtube. Here it is below. You'll notice the whine/rattle matches engine revs. Any ideas on what the problem may be?

 

sounds like your supercharger\waterpump.. if you haven't serviced that area before it's time with your mileage!

 

Buy a cheap stethoscope (one for mechanics of course), it will at least help you pinpoint the exact source. Personally, I'm not familiar with this sound, but when my alternator started making an awful sound, I had to stop on the side of the road and couldn't tell what was making the noise. With a stethoscope, it's only a matter of hearing where the sound is coming from and go from there.

 

A length of tubing stuck up to your ear can also work for a stethoscope.
I can't say I've heard that sound, but keep us informed of it's location and maybe we can help further.

 

Actually tubing is better for locating air leaks. You can make a home-made stethoscope with a long prybar or really long screwdriver or other rigid tool. Place one end on your ear and the other on various parts of the motor to locate the loudest sounds source. BE CAREFUL NOT TO TOUCH MOVING PARTS OR GET HAIR CAUGHT IN SPINNING PULLEYS. That would smart.

 

Thanks for the info guys...the sounds seems to be most loudest by the alternator/front passenger side.

What is the sound of the supercharger/water pump issue?

 

Usually it's a bit like valve ticking, faint knocking, hard to describe. Here's a nice vid I found that gives a good idea:
And as for reference, here's my own car, 05 S with a bad alternator bearing (keep in mind that noise can varies depending on what part of the component is going bad):

 

Well I used my long pry bar and put it against a bunch of things in the engine and the sound is most pronounced on the alternator. I will order a new alternator and install it soon.

 

So the issue was my alternator! After replacing it, all is good now.

Since I had a lot of things in the front off, I removed the supercharger and checked the oil and the back part had plenty of oil in it...so did the front but the front oil was all black. I ended up draining the front and replacing with new GM oil. I also replaced the waterpump eventhough it wasn't needed.

I had a pretty bad oil leak at the lower oil dipstick housing, the crankshaft position sensor, the oil pan, and the valve cover so I replaced the o-rings and gaskets for them.

 

I developed a short whine when I first crank up after sitting a few days. It goes away in about a second. didn't notice this before I changed the oil last time. Not sure if there is a connection? Levell is good.