|
Extreme
moisture problems |
|
Extreme
moisture problems |
The wire on the right was returned
by a customer because the vehicle was running poorly. It is from
a 4WD vehicle with a 16 valve SOHC engine used off-road, and is
typical of what occurs when preventive maintenance is neglected,
or not properly performed on this style of vehicle.
Diagnosis by automotive technician:
Faulty wires
Diagnosis by Magnecor:
This vehicle has been driven through lots of water and mud and,
over time, a large amount of water has collected in one or more
of the spark plug holes. The discoloration of the spark plug
connector indicates the water level may have reached the top of
the spark plug hole in which it was situated. Spark plug wire
connectors are not designed to operate under water, and on this
vehicle severe arcing into the water no doubt occurred, causing
the engine to misfire. Another connector not affected by this
problem is shown on the left.
All multi-part spark plug wire connectors are vented to prevent
them from popping off the spark plug as the engine heats up.
Therefore, each and every time the engine cools, moist air is
drawn through the tiny vent holes and a little condensation forms
inside the spark plug holes -- more so in humid climates and
during rainy seasons. Generally, most of the moisture condensing
in spark plug holes (there is no drain) will evaporate out
through the vent holes (in the top seal of the connectors) after
the engine heats up. In vehicles that are driven through water, a
great amount of water will flow over the engine and spark plug
connectors, and a certain amount will pass through the vent holes
into the spark plug holes. Unfortunately, as vehicles age, dirt
and oil accumulates around the engine and over the connector
covers, and if the valve cover gasket needs replacing, oil will
leak into spark plug holes to make matters even worse.
Suggested remedy:
The spark plug wire shown on right cannot be repaired
and needs to be replaced. Had the spark plug connectors on this
vehicle been regularly removed and the accumulated moisture (and
oil) around the spark plugs removed, no failure would have
occurred. If you run your vehicle through a lot of water, you
need to remove any water from in and around spark plug holes as
soon as possible. If you notice an engine miss or hesitation
(particularly when the ignition system is under load at low
speeds), you should have the problem investigated as soon as
possible, because water (and/or oil) in the spark plug holes may
be the cause.
More information relating to this subject is available on our
FAQ, specifically:
