N52 Rattle Under Load

[coupedan]

So I have noticed over the last few days that when my car is first started (2006 3.0si) and driving under load, there is a rattle which sounds like marbles in a can between 2000 and 3000RPM.
I can't really hear if it continues up through the rev range due to exhaust noise and road noise.

The noise is there whilst the oil is cold is but seems to disappear after around 30-40 mins of driving.

Now, I know this sounds like the dreaded VANOS issue but upon reading this doesn't seem very plausible as no one else has had these issues.

It's not the usual HVA tick either as mine has done that before on short journeys.

Just a question to see if anyone else has had the same issue or similar.

Car is currently on 122,000 miles

Cheers,
Dan

 

[Monkeydonkeyratmagic]

1st off I'd stop driving it and get it taken somewhere to check in out. Mechanical noises like that do not heal themselves and just get far worse and more expensive over time.

 

[ph001]

Vanos issues on the N52 are not very common so wouldn't be top of my list. Can this be heard revving the car whilst in neutral? If so can you get a helper to rev while you take a vid and host on youtube?

 

[rally-chris]

The DMF (Dual Mass Flywheel) is a common source of rattle on N52 engined Z4s, and is usually noticeable at idle or during engine shutoff. As the DMF is there to absorb engine resonances at particular parts of the speed range I'd say it's also quite possible to become noisy at specific RPMs. Do you know if the clutch and flywheel have ever been changed?

Chris

 

[Marlon]

I have the DMF rattle but only noticeable when stationary and at tick-over - depress the clutch and it disappears. Its a definite 'rattle' noise - apparently its nothing to worry about.

 

[Ed Doe]

Could be disa man - mine seems to do similar?

 

[coupedan]

Sorry guys for the late reply, haven't been able to get to a computer all weekend..

So, it gets a bit different from my description above, I tried to really tell what was going on on my drive home Friday.
It seems the rattle is still there when the engine is warm, just sounds a little quieter.
Car also feels down on performance, I had it in 3rd gear at about 30mph which went into a 60mph limit and thought I'd floor it.. the car took what seemed an unusual amount of time to get to 60 :?

1st off I'd stop driving it and get it taken somewhere to check in out. Mechanical noises like that do not heal themselves and just get far worse and more expensive over time.

I have it booked in with my specialist TWG Camberley for the 4th December but that's a little while yet and I will need to drive the car occasionally between now and then.

Vanos issues on the N52 are not very common so wouldn't be top of my list. Can this be heard revving the car whilst in neutral? If so can you get a helper to rev while you take a vid and host on youtube?

Tried hearing this whilst in neutral and holding my foot on the clutch, from what I can tell... I cannot hear it.

The DMF (Dual Mass Flywheel) is a common source of rattle on N52 engined Z4s, and is usually noticeable at idle or during engine shutoff. As the DMF is there to absorb engine resonances at particular parts of the speed range I'd say it's also quite possible to become noisy at specific RPMs. Do you know if the clutch and flywheel have ever been changed?

Chris

I know I do have clutch and flywheel rattle but this is a completely different noise to that (as far as I can tell) but the clutch / flywheel have never been changed (I got the car on 40,000 miles) so would doubt it would've had one since then.

Could be disa man - mine seems to do similar?

In a way I am hoping it's DISA, at least that is a reasonable fix, instead of something like VANOS which has the tendency to be rather expensive.
Ed.. does yours have an almost "Running low on oil" resonance to it when you are feathering the throttle at 2-3k RPM?
Sounds very much like this video here, although not as loud - https://www.youtube.com/watch?v=-wqgRJ0x040&t=23s