Noisy 330d on switch off

[Barkie]

Can someone please explain to me what is the cause of the rattle type noise when i turn off the engine. Some guy's said that if you keep the clutch in the noise is less. Mine stays the same.

 

[applehero]

I think it's related to the engine passing through a natural frequency when turning off the engine. There's an assosciated large engine movement with the rattle. Is that what you meant?

 

[Barkie]

The engine does move but it sounds like something is loose somewhere. Would like to know if i must react to it or not!
I have checked the mountings and seems to be fine.

 

[applehero]

Hmmm, on my 120d it sounds like a clatter. But has always done it. Has the sound got worse?

 

[Barkie]

No, it is the same since Jan when i bought the car.

 

[netercol]

mine does it too, but they dont do it when they are new, which leads me to the conclusion that it has to do with the injectors not being able to stop injecting instantaneously after they are say a 100k km's old, thus causing the motor to run on unevenly for a split second when you shut it down.. :dunno:

i mean we are talking about rail presures of 300 bar at idle here..

 

[P1000]

Never noticed anything like that on my 530d (same engine as 330d)

 

[haXor]

Mine makes a tractor like sound on power off. Now you have me worried..

 

[netercol]

Mine makes a tractor like sound on power off. Now you have me worried

doubt its an issue, unless the motor runs on for several seconds after being switched off..

 

[Barkie]

Well, what i can say, it does not fit the car! I feel better that it is not only me with these sound effects!

 

[applehero]

No, it is the same since Jan when i bought the car.

I wouldn't worry too much bout it then...

mine does it too, but they dont do it when they are new, which leads me to the conclusion that it has to do with the injectors not being able to stop injecting instantaneously after they are say a 100k km's old, thus causing the motor to run on unevenly for a split second when you shut it down.. :dunno:

i mean we are talking about rail presures of 300 bar at idle here..

That could be a possibility...

 

[haXor]

Mine makes a tractor like sound on power off. Now you have me worried

doubt its an issue, unless the motor runs on for several seconds after being switched off..

No it powers off on instruction! It was in for a Quality check at BMW on Friday so if it was a problem, I'm sure they would have picked up on it.

 

[ANiMOSiTY]

It's probably the reverse idler gear in the gearbox.
Happens to a lot of BMWs with some mileage on them.
Nothing to worry about.

(You have a manual 'box, right?)

 

[Barkie]

Yes it's manual. I must say i feel much better now. Is this something that need to be repaired or replace sometime?

 

[ANiMOSiTY]

Yes it's manual. I must say i feel much better now. Is this something that need to be repaired or replace sometime?

Ok - most likely to be the idler gear then.
Can you perhaps make a quick video for us?

A lot of the Getrag 'boxes in the BMs do that.
It's nothing to worry about.
If I recall correctly, some gearboxes have a replaceable bearing or bush within the idler gear - but most do not.