As my 01 Forester L was warming up last night, I poped open the hood to see if a headlight plug had worked loose (one headlight was out) and noticed a shocking sight!!!

 

There was small lightning bolts going from the top of my #4 spark plug wire to the "distributor". All the other wires were doing their normal thing but the #4 wire was acting like a plasma globe and sounded like a welder.

 

The kids were terrorified and didn't even want to get in the car after seeing this.

 

As it was dark, late and snowing, I didn't have many options but to drive it back out of the mountains. I also figured that it just didn't start because I happend to look at it. I assume it has been going on for some time now?

 

The car was idling a little eratically, while warming up, which is when I noticed this but ran well the rest of the trip.

 

What I tried: I tried re-seating the #4 wire several times to make sure it was pulged in all the way (top and bottom). I did the same thing on the wire next to it.

Results: Didn't change anything.

 

What would cause such an electrical show under my hood?

 

Confused,

Glenn

82 SubaruHummer

84 GL

01 Forester L

Have you tried replacing the wire yet?

 

I have heard of mechanics seeing this effect as a result of bad wire insulation.

The high voltage is seeking the lowest resistance to ground. You might try changing the plug out to see if it is bad or if you can swap the wire for number 4 with another you can see if the problem is the wire itself or the plug. It may be best to change the wire anyways as a 'low resistance path' may have developed through the insulation by now.

 

The fire can be a little scary but it usually isn't a problem and happens fairly commonly. Though if there is a fuel leak near this you can bet other problems will be happening and the fright level goes way up.

You have a bad spark plug wire or a hairline crack in the coil tower. This is nothing to be alarmed about and happens on a lot of cars. Just means it times for one of those two to be replaced.

It is actually a common way to diagnose a ignition issue.

 

 

nipper

Have not tried anything yet, I wanted to try the board first.

 

Didn't want to buy wires or take it to a dealer before the Experts (the Board) had a shot at it.

 

Thanks,

Glenn

You should be able to fix this yourself with no problem though the plug may be hard to get at.

Ok, I go get new wires and get ready to put them on.

It's dark and I open the hood and no sparks?

 

What's up with that?

 

I'll probably replace the wires anyway but how come the sparks are gone?

 

Only thing I can think of is when it happened it had been snowing/raining all day

and was extremely humid outside but nothing was wet and the car had not been driven that day?

 

Just plain weird:confused:

Glenn,

82 SubaruHummer

84 GL

01 FrankenForester

 

Wire prices...

Pepboys $82.00

Checker $40.00 but they don't have any

Dealer $44.00 for OEM:D

They only do it when wet. This is also why you replace the wires on a regular basis. When a wire goes bad it can arc and take out a coil too.

You are correct about the moisture in the air. Spraying a light mist of water from a spray bottle over the ignition area can help show up these kind of problems. Since you are replacing the wires, I would recommend you replace the plugs also at the same time.

 

Ok, I go get new wires and get ready to put them on.

 

It's dark and I open the hood and no sparks?

 

What's up with that?

 

I'll probably replace the wires anyway but how come the sparks are gone?

 

Only thing I can think of is when it happened it had been snowing/raining all day

and was extremely humid outside but nothing was wet and the car had not been driven that day?

 

Just plain weird:confused:

Glenn,

82 SubaruHummer

84 GL

01 FrankenForester

 

Wire prices...

Pepboys $82.00

Checker $40.00 but they don't have any

Dealer $44.00 for OEM:D

and coil if I found any damage. The arc can easily damage both. I am going to do this on my own car soon even though it runs perfectly as PM.