Hi all,

My car (1.6 Petrol Duratec) has been acting up lately and I believe it has a slight misfire. It seems to be quite random, some days the car drives fine and others it is sluggish and hesitant on acceleration and when lifting off. Exhaust is also chugging a little and engine shakes slightly erratically when idling. Does this sound like symptoms of a misfire? I have changed the air filter and it's still the same. I was thinking of changing the coilpack, ht leads and spark plugs - what should I change first or should I just change all of them - I've heard that a bad coilpack can damage the ht leads and vice versa. Any advice is appreciated.

Thanks :)

Hi,

I don't know if you've read earlier post on previous page (coil pack trouble) but

I have just cured my misfire with a coil pack from the scrap yard . I got the yellow

engine light on while my car was misfiring , especially pulling back when going up hills.

Once I got the car back home I read the codes of the ECU which displayed code p0304.

This code points the misfire to cylinder 4 , I then had to find out what was causing it

so I swopped Spark plugs round and HT leads round but still no joy on cylinder 4, so this

then left the coil pack. I did some research and everyone said get a genuine Ford coilpack

so before forking out on a brand new one I managed to track one down from the scrapyard £15

The Mondeo, KA , Focus and many more Fords use the same packs so plenty round. So far 48 hrs

later car running fantastic and no engine light. My Car as 64k on , I don't know what your milage is.

For the sake of £15 its worth trying to put a different coil pack on, If it fixes

it good news if not you can rule it out.

Sorry for long post but hopefully something above may help you ...cheers ....

I agree with the shaymen, stick with a genuine coil pack if you do decide to change it.

I've heard that a bad coilpack can damage the ht leads and vice versa. I've never heard of the coil damaging the leads but i have heard of cases where the plugs or leads have caused the coil pack to fail - i have been here myself. I went through a few coil packs on my 2001 focus, replacing them with 'genuine' units every time along with new plugs. i also replaced the leads (bosch) but they still continued to fail. in the end i fitted another 'genuine' coil pack, genuine leads and plugs...end of all the problems.

Before i bought my focus a mate did tell me that the focus seemed quite sensitive to spark plugs - after my experience i would agree.

If you do a search on ebay for a genuine coil pack, you will see them for around £35. these are the units i was using, apparently they are oem units without the stickers..

Thanks for the info guys. I've been quoted about 90 quid for coilpack leads and spark plugs from a Ford dealer selling on ebay is that reasonable? I think i'll have a bash at changing them myself as it doesn't seem too difficult in the Haynes manual. What size spark plug socket do I need? Is there anything I should worry about when doing this job.

Thanks for the info guys. I've been quoted about 90 quid for coilpack leads and spark plugs from a Ford dealer selling on ebay is that reasonable? I think i'll have a bash at changing them myself as it doesn't seem too difficult in the Haynes manual. What size spark plug socket do I need? Is there anything I should worry about when doing this job.

if thats for genuine parts then thats a steal! just realised your car is a 57 plate too

Its a very easy job, make sure you have torx bits though. i cant remember the plug size of the top of my head