Focus 1.6 miss fire

[The_Burg]

Help, car developed a miss fire. Having a google it seems common issue is water getting in the plug wells.
This it most certainly had. I dried as much out as possible with kitchen roll then left it to warm up and pulled the caps and let it evaporate. Fitted new plugs, cleared the code and seemed Ok though a bit feeble.
Wife went to drive to work this morning got about 5 miles and miss fire is back. Fitted new leads and still there.
There was a bit of water in the well but this has evaporated out now.

Seems the next step is coil pack.

Question reading up it seems 1 and 4 and 2 and 3 fire together so is it ok to swap 1 and 4 over to see if the fault moves cylinders before buying a new coil pack? I don't want to waste money. Google pad on charge so not managed to get fault codes yet.

Another question, would it be better if the plug caps didn't seal so water could evaporate easily rather than being steeped in steam?

[Limpet]

It's OK to swap coil packs over for testing purposes.

If you need to replace any, don't waste money on aftermarket/pattern ones no matter how reputable the supplier, or what brand they are supposed to be. Buy genuine Ford packs from a Ford dealer parts department.

This is based on bitter experience with a relative's StreetKa.

[GreigM]

Have you tried new plugs?

[The_Burg]

GreigM said:

Have you tried new plugs?

New plugs on Friday and cleared for a while, just fitted new leads too. Little bit of water in well 4.
Left cap off to evaporate and will check later when the googly pad is charged and i can get any new fault codes.

[Krikkit]

I would think the coilpack's been duffed, assuming all the plug leads are in good condition!

[The_Burg]

Krikkit said:

I would think the coilpack's been duffed, assuming all the plug leads are in good condition!

Leads new, replaced them in the last couple of hours.

[Limpet]

Coil packs are pretty common failures on Fords of this era. You can quickly identify/eliminate this with one of those cheap HT testers, and by swapping the coils over if you find a problem.

[The_Burg]

Typically leads couldn't be swapped. Re-read codes. Moved to cylinder 3 from 4. Different part of coil pack so looked good to go.
Reseated all HT leads and the lead to coil pack. Cleared codes.
Went for a drive 15 miles, no further issues.

Fingers crossed that's it!

Still concerned over water in plug wells, though it's now 7 years old a 70k miles so i guess it's not a biggy.

[The_Burg]

Another 20 mile round trip completed without issue.

Just as well MOT due end of next week.