Whining sound from engine bay

[Phate]

Hi Guys,

A couple of days ago I started to notice a whining (maybe whistling) sound coming from the car under light throttle pressure, it happens in neutral, drive and when stationary and just applying a bit of throttle. I've had a good google around and there seems to be an issue with intake hoses on E46 models but nothing concrete about the E85/6. Also, this only happens when the engine is warmed up, from cold there's nothing which also leads me to think maybe it's some rubber piping which is expanding as the heat increases.

I had a look under the bonnet yesterday and it seems (to me) that it's coming from the front area of the engine bay but the intake hose I mentioned above is down on the right hand side as you look from the front, or am i wrong/it's different to the E46. The aux belt was near the sound source but seemed in good condition though so not really sure.

Going to take it to the garage this week, but if anyone has any ideas/experienced similar I'd greatly appreciate any advice.

PS would anyone advise against driving until it's sorted?

Car is an E86 3.0si auto if that helps

Thanks

 

[Stuart Truman]

Are you sure it's not a belt tensioner bearing?

 

[Phate]

Hi Stuart,

I'm really not sure, would that only occur when warm? I've just been out and recorded a video I'll try and link it on here if that helps. It does sound like its coming from the front where the aux belt is so could be that...

 

[Phate]

https://www.youtube.com/watch?v=i5XlLXYYzhA

This should be it, thanks in advance for any help

 

[Stuart Truman]

That sounds like a tortured bearing, possibly in the alternator. Belt tensioners are normally high pitched

 

[Phate]

Any ideas how much that will set me back at a garage? :?

 

[Phate]

Just to follow up on this. Took the car to my local BMW specialist, on quick inspection on my lunch break he couldn't find the cause of the problem but was sure it wasn't the intake hoses and not likely the alternator.

So yesterday I dropped it off for a propper look and it turned out to be the oil filter which had collapsed He said he hadn't come across anything like that before but having got home I've seen a few occurrences of this on e90s and is potentially caused by someone fitting the filter incorectly or using one that doesn't match the OEM spec.

Anyway £10 part later its back to normal!