X3 F25 Xdrive35i Metallic Rattling Noise

Hi guys,

I have a 2011 x3 xdrive35i, bought it with 106k km it's now on 120k. Had no issues so far at all but there is a nagging noise that has been bothering me since I bought the car.

Whether it's hot or cold if I start it and let it idle (even when letting turbo cool down when I get home) I will hear this metallic rattling noise that I just can't find.

The best way I can surmise this noise is imagine the noise of a heat cover on an exhaust header not being properly bolted on, thin steel like that rattling, yet as far as I know and can hear the heat shield on my car is not rattling by any means.

I've climbed underneath but still could not pin point it. Could this be the dreaded wastegate rattle? Or is it something else?

There is no lack of boost or power for sure as my humiliation of a MK2 Ford Focus St 2.5T with a cannon the size of a cooking pot as an exhaust the other day assured me, the look on his face when this family wagon destroyed his car was priceless!

Boost kicks in when it should and it pulls great, never any issues.

Anyone had similar issues with this platform and is it something I should have investigated if it's not causing anything more than an irritating rattle?

Your guys feedback would be appreciated. Thanks Brent

Maybe a little sound clip or video will help ?


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Will post one first thing tomorrow, tried to record one before from the front of the engine but the noise of the belt and injectors drowned it out.

I’m willing to bet this is the v-belt tensioner.

Ours made a rattle sound when revving softly off idle- as the tensioner adjusted for the belt.

Is it a constant rattle? Or now and then?

gavsadler said:

I’m willing to bet this is the v-belt tensioner.

Ours made a rattle sound when revving softly off idle- as the tensioner adjusted for the belt.

Is it a constant rattle? Or now and then?

Click to expand...

Yeah i would check this first as well.

It's a constant rattle, only on idle though, once one is revving the car it disappears.

How would one go about checking the v-belt tensioner? Would it visibly rattle and then stop when the belts rotate quickly?

Also this begs the question, would I need to replace it or could I live with the noise? Would hate to get stranded with no power steering etc

Thanks in advance,

Brent

Here is a video of the noise:


Although one can't place the location in the video, it is coming from the front right, I jacked it up and listened all around, definitely coming from the area right front.

Let me know what you guys think!

Cheers

brentbmw said:

Here is a video of the noise:

[video=youtube]

Although one can't place the location in the video, it is coming from the front right, I jacked it up and listened all around, definitely coming from the area right front.

Let me know what you guys think!

Cheers

Click to expand...

Have embedded the video for you :thumbs:

Can't hear it all that well, but the symptoms sound a lot like the issue I have.

Its a metallic clicking (front right of engine bay), which my mechanic has diagnosed as the tensioner starting to act up. Switch your aircon on, with the bonnet up and see if the clicking gets louder/more frequent..

Hi there,

Thanks! Yes it does get considerably louder with the air con on.

Can I drive it like this until it goes or is it something that needs attention asap?

Cheers

brentbmw said:

Hi there,

Thanks! Yes it does get considerably louder with the air con on.

Can I drive it like this until it goes or is it something that needs attention asap?

Cheers

Click to expand...

Definitely the tensioner then.. I would monitor it and get it changed when convenient. I have mine scheduled for December, its pretty inexpensive for the E90, should be similar for your car. The tensioner itself is less than R1k from the agents, then change your belt for another R500 (or less) and then the cost of an hour's labour.

If the tensioner breaks, you risk damaging all belts and surrounding parts including cooling system components. Given the cost to replace vs the damage if it breaks, I would rather have it done for peace of mind.

If you close to the edenvale area, i can do this for you
PM if you need

I would also have a good look at the dampener pulley as they start to make a noise when they are on their way out. My old X3 2l diesel also had a funny ticking noise for about 2 or 3 thousand kms and then it threw the aircon belt whilst towing my caravan in summer. Fortunately i got home safely and then only realized it was the crankshaft dampener pulley.

Thanks for the tip just checked it out.

Put a camera down there to inspect it and luckily there is no cracking at all on the crankshaft dampener pulley.

Warranty is covering the belt tensioner luckily, does anyone know a good RMI approved garage who work on BMW in the Rustenburg area?

Cheers

Also another tip to check the tensioner: watch it closely and get someone to blip the throttle lightly, you should see it jiggle about.

Also: even when 'worn', there is a helluva lot of tension on the thing, so just be wary if fiddling there with fingers.

Here's a link to my tensioner when it was on its way out:

[video=youtube]

It's most definitely the tensioner then!

Mine is quite a bit worse than that, it's jiggling even under idle and when the air con is on then it jiggles as bad as yours was under a little throttle.

Going to get it sorted as soon as work allows.

Luckily only do about 800km a month nowadays.

Thanks for the assistance :thumbs:

Had a very bad noise on my son's 2001 E46 320d auto especially at idle at a stop sign or red robot. Car would make this absolute bad racket, so much so that it was embarasing. I had checked out the pulleys and even replaced the tensioner complete with bracket and pulley. Made no difference at all!! I even replaced the gearbox mounts and iirc, the engine mounts but still no difference. I then suspected the power steering pump but fortunately did not get to replacing it. Also saw the tensioner moving a lot when idling. We had the crank dampener pulley replaced on this car the year before and it was about one year to the day that we took the "new" pulley back and asked to have it replaced under warranty from Goldwagen. Put the new pulley on and noise and vibrations gone!!! The previous "new" pulley was out of round and was making the racket by pulling and releasing the tensioner causing the noise. Just my 2c's

Yeppers, mine has the same symptoms and the parts from the agents are expensive as expected.

What causes the tensioner to go bad in the 1st place in my case is the OFH gasket on the coolant side. All the leaked oil, grime and grit drops down and gets into the pulley assemblies of which the tensioner seems like the 1st to go.

Picking up the parts at a 3K damage to the wallet and will attempt to do this tonight. Can't part with another 3k for someone to do it for me.

Any pointers will be welcomed.