I wonder if anyone could help me figure out where a new noise and vibration is coming from on my '04 Cooper S. This just cropped up within the last couple of weeks, and unfortunately about 1500 miles after my 50,000 mi warranty ran out.
The noise is a low rumbling sound accompanied by a vibration that I can feel through the floor. It comes and goes in uneven cycles, but is present probably 70% of the time. It's always the same pitch (doesn't vary with car or engine speed).
I was initially thinking a PS fan failure? However, got under the car last night and the fan is running. It does make a noise and vibrates some, but when I got up close to it it didn't seem to be loose or making huge amounts of noise. Could it be worn enough that the vibration comes through the car and is audible only inside, but tough to feel in the already noisy and vibrating engine area?
I don't want to buy a new PS fan if this isn't the cause of the issue. Could it be something else?

 

if it's a groaning noise then check your pcv line . it's the line to the passenger side coming off the valve cover . this line fails and collapses. . making a groan and uneven idle . just a thought.

 

I think it has to be something heavier than that - I can feel the floor of the car vibrating when this noise kicks in, so it's got to be something either heavy or bolted solidly to something I would guess. I'm going to get a helper to sit in the car this weekend and tell me when the noise comes and goes, and I'll look for what is in sync with that and report back next week.

 

Sounds like the PS fan to me. I see those fail all the time... or in your case become noisy. They lose the small weight on the fan blade. Check and see if the fan spins freely - with the car off of course!!! If it's sticky, replace it, it's your problem.

 

Well, I did more investigating today. I got under the car and watched the PS fan, and had my girlfriend sit in the car and tell me when the noise & vibration started and stopped. The PS fan was on the whole time, and it spins freely when off, so I'll rule that out as the source of my problem. Too bad, since it's cheap and easy to replace!

What I did figure out is that my noise & vibration are in time with the high speed radiator fan - but out of phase. So, when the main fan is on high the noise and vibration are not there, but when the main fan slows to regular speed the rumbling noise and vibration kick in.

What do people think of that? Could the main cooling fan bearings be going bad or something, and only vibrate at the lower speed? Replacing that sounds like an expensive job. Is there anything else that operates along this pattern?

 

I've noticed a similar issue on my MINI. A little noise and vibration which I can feel through the floor board. Does it maybe 20% of the time. Thinking it might be the PS fan. An 06 MCS, with only 16K miles.

bumping the thread to see what the OP figured out.

 

It was the steering pump that had gone bad. Replaced under warranty (goodwill at a very excellent dealership in Kansas City). If you can feel the vibration, I believe that it is almost certainly the pump as the fan is too small and light to transmit much vibration through the floor. I would have your dealer investigate. For me, the vibration could be brought about by turning on the A/C (I think the pump runs and cools itself in time with the A/C high speed fan), but I knew it was a PS issue because the noise changed if I turned the steering wheel (which it would not if it was a problem with the A/C or main cooling fan).

 

Literally shocked at the number of folks (myself included) who have failed power steering pumps. IMHO, this issue should be a recall.

 

Was the noise you were hearing a rattling sound coming from under the engine. I have one of those right now. :(

 

No, not a rattling noise. More of a loud, low rumble for me.

 

I have a sort of rattling that is coming from the scoop of the car. Can really hear it coming out of the scoop. When the engine is idle and the car is just sitting there it is a rattling that would almost sound like it is a fan or the supercharger running with bad bearings but it much louder than I have ever heard. Then also you can only hear it a little bit from inside of the car. I am afraid that it is the supercharger. I have an 04 mcs. Anyone have a similar problem?