fiesta 1.25 2008

[rikki_essex]

A friend of mine at work has had this car from new and now when he comes off the acclerater it pops (exhaust noise) after about a mile of driving and contiues to do so through the rest of his trip. He has taken it back to ford and they told him its normal he then asked why didnt it do it from the start and there answer was you probably never heard it. Firstly is it normal? secondly if its not normal then any ideas what it would be? 

[geoffr70]

You say when he comes off the accelerator it pops, so when it is decelerating, is it lots of little pops? I had an old MR2 turbo and when the exhaust was hot, very hot, after a spirited drive, on unbraked deceleration it would pop in the exhaust. Don't know if this is the same but as far as i'm aware it's unburnt fuel igniting in the exhaust system somewhere. It might be running too rich, I don't know I'm no expert.

[Kevin Wood]

Normally lean running, or there's a leak at the manifold letting air get drawn into the exhaust.

Kevin

[Kevin Wood]

Thinking about it, fuel should be cut off on the overrun, so if it's popping and banging for more than a second or so after lifting off I might be inclined to check the throttle position sensor / switch.

Kevin