I own mk2 focus and I keep having wet spark plug leads,which causes miss firing.I cant see any leaks from the washers or seals.Im worried that too much water will run down the leads and seize that plugs in the head.Could it be condensation?
Any info would be great.
Thanks Bryan

Bryan Roberts, October 2009

Hi
I also have a Mk2 focus on a 05 plate which developed a misfire on Monday,I limped to work and pulled a plug lead off only to find the gap between the cams full of coolant.When I removed the rocker cover there are 2 small core plugs which were corroded and one was leaking coolant.A friend fitted 2 new plugs in situ but I still have a misfire due to (I think) damp leads,which I will try to dry or replace.
Hope this helps
Nick

Nick, October 2009

I don't know whether this is relevant to the focus engine but my daughter had an Escort with a similar problem. Turned out to be a leaking core plug in the cylinder head. When the engine warmed up, a fine spray of water was directed onto the spark plug and caused a misfire.

ChicksFan, October 2009

The leads are sealed into the top engine casting - a tight push fit - so its most unlikely that water would get down there.

John, October 2009

The plugleads are fords own,but thanks for the the quick replies and info guys

Cheers

Bryan

Bryan, October 2009

How old are the plug leads? Are they decent quality or halfords cheapest?
Good leads should be able to cope with a bit of damp without arcing out.
If you cant get new leads, at the very least give the old ones a spray and wipe with WD40 or similar to keep the dampness off them.

fresno, October 2009

A spark plug body makes a gas-tight seal in the cylinder head hole - it has to else the engine won't run properly. If gas under pressure can't get out then water at normal atmospheric pressure will not be able to get in - there is no chance of the plugs rusting up in their holes.

The water collecting on the plug leads is very probably condensation - at this time of the year everything is covered in condensation in the morning.

If you garage your car at night let it cool down outside for an hour or so before putting it to bed.

Any moisture in the warm air of the engine compartment will be able to evaporate in the breeze - no breeze in the garage and the latent heat of the engine will continue to warm up the air around it - increasing the moisture content of the trapped air which will condense out as things later cool down.

Peccavi, October 2009