2003 BMW 330 Ci Auto - Weird Noise

[Divesh23]

Hey Fanatics,

Hope everyone is doing well and keeping safe!

I recently decided to buy a 330 Ci as I've always loved the look of the drop top and the 330i sound is just so awesome!

A few weeks ago I took the car in to a reputable gearbox specialist to sort out a leak, but after fetching the car I noticed a weird rattle/ticking (diesel engine like) sound when driving. I took it back and they said the sound is not coming from the gearbox and not related to any work they did.

It's an odd rattle/ticking sound that increases as the revs increase. The sound is predominant when driving at low revs (at higher revs I think the exhaust tone takes over) and if the car is in neutral and you rev it the sound its evident. 

I took the car to my local BMW Mechanic and he cant seem to pin point where the sound is coming from. 
The sound is audible from inside the car with the windows up and you literally cant pin point the same sound when outside or with the bonnet open. 
I've only had the car for about 3-4 months and haven't driven it much but the noise doesn't seem to be impacting performance.

So far I've check the DISA and it has no play on it at all, I replaced all the vacuum pipes & pcv thinking there could be a leak causing the issue. I doubt its the vanos as theres literally no noise coming from the vanos when you open the bonnet. We've check pulleys and all seems fine, the power steering pump has a slight whine and i'll replace that next week but I doubt its the cause of the mysterious sound.

[font=Tahoma, Verdana, Arial, sans-serif]YouTube link of the sound while the car is in neutral: [/font][font=Tahoma, Verdana, Arial, sans-serif]https://youtu.be/rGzt12OsFy4[/font]

Not sure what else to check???

Has anyone experienced anything like this before?

:dunnoanymore:

 

[Peter@AEW]

Does it have the rattle noise at idle?
Does the noise increase with revs?

Is it almost like a rattle like steel against steel?

If so vanos rattle.

Rattle kit repair

 

[Steph745]

Is VANOS rattle audible from inside the car with the windows up? Wouldn't that be easily heard and pinpointed from the engine bay with the bonnet up?

 

[Divesh23]

Does it have the rattle noise at idle?
Does the noise increase with revs?

Is it almost like a rattle like steel against steel?

If so vanos rattle.

Rattle kit repair

Hi Peter@AEW,

So I thought it was the vanos rattle or seal issue however when opening the bonnet and you can’t hear the rattle/ticking sound that’s evident from inside.

I’ll try to post a link with the sound, perhaps that will give more insight into the issue.


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Is VANOS rattle audible from inside the car with the windows up? Wouldn't that be easily heard and pinpointed from the engine bay with the bonnet up?

Hi Steph745,

So my thoughts exactly, most of the Vanos rattle issues and even the disa flap issues are very evident the moment you open the bonnet.

This sound is virtually impossible to trace in the engine bay but is so clear inside the car and it only started after fetching the car back from having the gearbox leak fixed.

I’ll try to post a link with the sound.


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YouTube link of the sound while the car is in neutral:

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[Andre1983]

That'll drive me nuts! GL!

Sent from my SM-J720F using Tapatalk

 

[Tinuva]

Sounds like the HVAC fan.

Turn off the fan and aircon completely inside the car then try again.

 

[Divesh23]

Sounds like the HVAC fan.

Turn off the fan and aircon completely inside the car then try again.

 Hi,

Aircon and fan was off when I did that clip...

I think I'll inspect the internal blower fan as well.

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That'll drive me nuts! GL!

Sent from my SM-J720F using Tapatalk

Hey Andre1983,

It's horrible. If I have the window down then I barely hear the sound and the awesome exhaust note takes over at higher revs, but it truly spoils the driving experience when just cruising.

 

[Tinuva]

Oh I see now the HVAC is turned off.
You do have the radio on, but the noise is louder when you hold the phone close to the middle airvent and top of the dash.

I recall there a random thread on the e46fanatics forum where a guy was hunting for something similar to this. He ended up taking out the whole dashboard piece by piece to find it. Was something silly in the end but he found it after that whole exercise.

 

[evnmopwr]

Can you only hear it from the inside??
Or if you stand outside, Can you hear it.

I think you need to try and isolate where its coming from.
Then base your search on that Narrowed down Results

to be safe, Get you a Mechanics Stethoscope.

Have someone keep the car on a rev and Put that scope all over on the engine just to be sure.

Sadly, my first e46 had a "rattle" which i thought was water pump. it eventually got so bad that people would look at me weird as i drove. When i pullled all the belts and started the car, noise was still there.
Got the scope and when i put it on the sump. rattle was evident. :'( ( Spun a bearing on rod 3 ).

Not saying this is your issue. but do what you can to isolate the issue.
If its just inside you hear it, Then Something with HVAC.
in that case, Maybe the BLower Motor Bearings is shot

Try putting your fan on FULL BLAST and see if it stops making that noise.

 

[AndreB320i]

Have you made any progress with that rattle ?

I have not had the problem, but in my hunt for a vibration issue on my 320i Auto (after gearbox experts had their dirty hands on it) we started looking at flex plate issues and apparently a cracked flex plate can cause a rattle sound. If the gearbox was out the flex plate probably came into play. Autos don't have a flywheel where the clutch would usually mate, but a "flex plate". 

Just a thought.

 

[Divesh23]

Have you made any progress with that rattle ?

I have not had the problem, but in my hunt for a vibration issue on my 320i Auto (after gearbox experts had their dirty hands on it) we started looking at flex plate issues and apparently a cracked flex plate can cause a rattle sound. If the gearbox was out the flex plate probably came into play. Autos don't have a flywheel where the clutch would usually mate, but a "flex plate". 

Just a thought.

Howzit,

So it actually turned out as bad lifters towards the rear of the motor. Strange that it suddenly started acting up out of nowhere, but all is well after replacing all of them.