Funny Rattle at 1400 rpm

Hi,

I'm getting a funny rattle at 1400 RPM.

It can happen anywhere in the range of 1400 to 2100 RPM

I thought it was just happening on turning the steering wheel - but in fact it's most noticible when going really easy approaching into a roundabout or straightening coming out.
(Some of us don't rev into a roundabout )

It's a low frequency maybe 4-5 Hz rattle - coming from the engine for about 1-2 seconds - it goes on throttling up.

It dosn't affect power output or steering or anything -

Any ideas???

Thanks

tom

is there a female in the car when ye get this funny rattle

eliminate wheter the noise is in engine rotatation, do this by reving out of gear and stationary.... or if its in wheels/ drivetrain rotation when moving.. also try with clutch in and out and come back to us

Nearly sure someone said on here before that when the cat starts to break up you end up with a sound like stones in a can. Could it be this??