Auto choke noise?

[ric220]

Not sure how to describe this but here goes...
When starting my w124 E280 from cold there is a loudish buzzing / humming noise from somewhere under the bonnet (not very specific I know!). This lasts for the first few miles then suddenly disappears and does not reappear when starting from warm. I assume this is something to do with the auto choke / warm-up process, but am unsure whether it should be doing this quite so loudly? Maybe that's the way its been designed but I'd appreciate any comments / solutions costing less than £0.25.
Cheers
PS - the gearbox is reluctant to change up above 2nd during this initial period, but I don't know whether this is relevant.?

 

[television]

The gearbox will not change up until the CAT is warm, it will stay in second as long as possible, that's normal. if you go over 30 MPH and back off the throtle,it will change up
We don't have chokes with injection systems, we have fuel enrichment devices.
you do have a lot of vacuam pipes in the engine compartment,these can come off or leak, could be the cause of the noise, but impossible to say without hearing it.


Malcolm

 

[brianha0]

I have the same problem and i put it down to the turbo as it was only when i was accelerating and when the engine warmed up it stopped.
Regards Brian