intermitent power loss

[Jonny112]

when accelerating from cold sometimes my 1.4 would have no power it feels like stomping hard on the brakes then all of a sudden it would just speed up :s any ideas ? changed the oil and filter today there was some small metal shaveings in it

 

[Mar172]

when accelerating from cold sometimes my 1.4 would have no power it feels like stomping hard on the brakes then all of a sudden it would just speed up :s any ideas ? changed the oil and filter today there was some small metal shaveings in it

Need it to warm up really ,