#4 plug wire problem

My 95 Civic LX started "missing" three days ago. It's been raining a lot.
Upon inspection, the #4 plug wire had popped up out of the valve cover -
approx. 1 inch and was wet.

After drying the wire off, and drying out the hole, it ran OK for 1/2 day
and then popped off again. I swapped #3 & #4 spark plugs, and the problem
stayed in #4. When the wire is re-inserted, the problem goes away, but
returns shortly thereafter.

Any ideas?

Thanks!
DGB

 

Two things are combining to do this - pressure build-up in the crankcase and
a leak in the seal for the #4 spark plug well.

First, give the crankcase ventilation system a good cleaning. This means the
PCV valve (replacement is better than cleaning since you already have
symptoms), cleaning / checking / replacing hoses and cleaning out the
fitting where the PCV hose goes to the manifold.

If the plug wire still pops out, you will need to replace the spark plug
well seals. It isn't a big job, but I'm sure you need to remove the valve
cover to do it. That means replacing the valve cover gasket, also a minor
job and expense. The only special tool needed is an inch-lb torque wrench.

Mike

 

Absolutely.

Buy a set of OEM wires that FIT PROPERLY.

Your aftermarket wires DO NOT FIT.

 

you physically swapped out both of the spark plugs, not just the plug
leads? and they're both screwed all the way in properly? try measuring
with a piece of rod down the hole against the plug top to ensure #4 plug
is screwing all the way home. if not, you need to CAREFULLY chase the
head thread.

the only times i've seen this kind of thing is when the plug has blown
either completely or partialy out of the head - usually because it
wasn't screwed in properly in the first place. the plug leads
themselves, while close, are not an airtight seal, so minor leakage from
the valve cover gasket should not be a big deal, but gross leakage from
the cylinder direct will blow a lead off no problem.

 

Check your spark plug. I'll bet it's cracked or has a gap between the
insulator and the anode.