Metallic rattle during engine idle

[anandoc]

Folks,

The other day I started up the car and noticed a rythmic metallic rattle coming from the engine bay. It was pretty cold in the morning (maybe -15C or below). There seems to be no performance degradation of any kind but I was curious what could be the cause of this rattle. The sound seems to come from the intake side of the engine. Here is a video for a lack of better description. Any tips would be awesome. Thanks!

[johnrando]

Is that the VANOS rattle?

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[BMWCurves]

Is that the VANOS rattle?

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Isn't the VANOS rattle more on the exhaust side of the engine?

To me it just sounds like a stuck valve/lifter somewhere, which wouldn't surprise me at start up in cold weather.

[anandoc]

VANOS rattle was the first thing that came to my mind as well - since that is a known issue on these cars and has not been addressed on mine. And to be honest, I am not 100% sure that the sound was definitely coming from the intake side ... but I am sure that it was not a heat shield or something else rattling outside the engine.

Is there any other way to verify (or rule out) that this is infact the infamous VANOS rattle? I can take another video from a different angle if required...

[Oli77]

Water pump is my guess. Mine sounded a bit like that. Put a tube to you hear and the other end near the pump (careful), should help you identify the source of the noise.

[anandoc]

Water pump is my guess. Mine sounded a bit like that. Put a tube to you hear and the other end near the pump (careful), should help you identify the source of the noise.

Hmm...I can give that a shot. I replaced the water pump (along with the entire cooling system, pulleys, belts, radiator etc) with a metal impeller in June, 2014 so I doubt the water pump going bad so soon. But thanks for the tip!

[Oli77]

For comparison, here is what mine sounded like.

Here

[ELCID86]

For comparison, here is what mine sounded like.

Here

That quiet??


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"ZHP is a garbage option anyway- just some cosmetic upgrades with a different cam and diff to claw back some of the performance lost fitting those hideous and heavy wheels. Any 330 with a 3.46 diff will smoke a ZHP every time. The whole Mafia thing reeks of childish behavior." - an e46fanatic

[slater]

Water pump is my guess. Mine sounded a bit like that. Put a tube to you hear and the other end near the pump (careful), should help you identify the source of the noise.

tube works, or you can get a cheap automotive stethoscope from canadian tire for under $10. i have one. it's handy for finding bad bearings and such!

does it go away with some throttle?

[anandoc]

tube works, or you can get a cheap automotive stethoscope from canadian tire for under $10. i have one. it's handy for finding bad bearings and such!

does it go away with some throttle?

It does seem to go away with some throttle when I am driving. Then again, its tough to keep track of the noise when I am in the cabin, driving the car. I will warm up the car and check for the same noise at warm idle and post another video.

The tube/stethoscope seems like a good idea.