Ford Fiesta 1.25 Ghia......Slight miss in engine

Wonda-Boy

Have a little run around separate to main car 00 D Fiesta 1.25 Ghia, 34,000 miles on clock and serviced and TB w\ water pump done because of age rather then miles, passed NCT no probs 3 mths ago. Drove home from Dublin on motorway yesterday flying no probs 70 all the way. Doing school run this morning and engine got lumpy on route to school, like its running on 3 cylinders. Checked all plug leads and all is fine. Idle drops low in neutral and lumpy till mid rev range and less noticeable in higher gears.

Any ideas lads....

Henry Ford III

Sounds like something on the ignition side of things. A plug, plug lead, coilpack........

p.s. Don't drive on 3 cylinders - it'll wreck the cat.

mickdw

Wonda-Boy wrote: »

Have a little run around separate to main car 00 D Fiesta 1.25 Ghia, 34,000 miles on clock and serviced and TB w\ water pump done because of age rather then miles, passed NCT no probs 3 mths ago. Drove home from Dublin on motorway yesterday flying no probs 70 all the way. Doing school run this morning and engine got lumpy on route to school, like its running on 3 cylinders. Checked all plug leads and all is fine. Idle drops low in neutral and lumpy till mid rev range and less noticeable in higher gears.

Any ideas lads....

Coil pack possibly

savagethegoat

agreed....easy DIY fix.... new coilpack plugs and leads

DakarVert

99% sure it'll be a coilpack, Most Fiesta/Focus Zetec engins suffer from it eventually.

Wonda-Boy

Got different leads on yesterday and one of the plugs was cracked at the top. So get 4 plugs today hopefully that will sort it if not coil pack next I suppose.

Many thanks for advice lads

kirving

Henry Ford III wrote: »

Sounds like something on the ignition side of things. A plug, plug lead, coilpack........

p.s. Don't drive on 3 cylinders - it'll wreck the cat.

I wouldn't risk it either, since that engine probably doesn't know that it's misfiring.

Slightly unrelated, but I did read in a Focus manual that the car will automatically put itself into 3 cylinder mode and use the fourth as an air pump to keep the engine cool if it overheats. Probably not a feature on the fiesta though.

mullingar

Kevin Irving wrote: »

I wouldn't risk it either, since that engine probably doesn't know that it's misfiring.

Slightly unrelated, but I did read in a Focus manual that the car will automatically put itself into 3 cylinder mode and use the fourth as an air pump to keep the engine cool if it overheats. Probably not a feature on the fiesta though.

If a coil pack is gone, every piston will still move up and down pumping gas in and out as they are mechanically connected together with the crankshaft.

The fault above may cause cat damage as fuel is still injected into the engine and its pumped out of the cylinder unburnt. Cats don't like raw petrol.

Henry Ford III

mullingar wrote: »

...Cats don't like raw petrol.

The only time a cat is likely to go "woof" in fact.