99 forester S series issues

[lost_driver]

Alright, i'm looking for any possibilities of what is wrong with my car. This problem started two days ago, and has already gotten worse.

 

The engine is shaking pretty bad. I'm wondering if it is a spark plug needing to be replaced. It seems like (and this is while it idles in drive) it isn't firing on all cylinders. Watching the RPM gauge, the normal RPM is about 500, but it will dip momentarily to about 250-300. I opened the hood to have a look, and the black box with electrical fixtures just to right of the center of the engine gave me a nasty shock when I touched one of the protruding rubber fixtures. I'm assuming that is not a spark plug.

 

Now, I will be changing the oil tomorrow as it is due for one anyway, but barring that, does anyone have any suggestions, pointers, or ideas on what is going on?

 

Thank you for your help in advance!

Edit/Delete Message

[bheinen74]

Do not touch stuff under the hood when car is running.

 

Sounds like a Spark Plug Wire.

with the car off, trace the 4 plug wires to the black box where they all hook into, and make sure they seem securely attached.

 

You probably are due for new plug wires, but since you got shocked, it tells me a loose connection, or badly worn plug wires, loose ground wire, or loose positive power cable some where

[idosubaru]

Your check engine light isn't on? If it is - get the code and let us know what it is.

 

Very typical cylinder misfire symptoms, which means it probably needs plugs and wires.

 

When was the last time it had plugs and wires replaced?

 

Also - avoid any aftermarket wires and use NGK only plugs on this engine. I've seen them be undrivable with brand new wires from the auto parts store.

 

There's a small chance you could need a coil pack.

[lost_driver]

The check engine light is on, i don't remember specifically what the code was, but it was an o2 sensor. They reset the light, and it drove fine for a month, then came back on.

[Fairtax4me]

You got a loose connection or split wire near the coil. Even with the engine running it shouldn't shock you. (Unless you pull the wire off) Electricity always takes the path of least resistance. You were the path of least resistance in this case, which means that the plug wire is loose or the insulation is cut. Or there may even be a crack in the coil case.

 

When it gets dark open the hood and start the car, no flashlight, you should get a blue light show near the coil pack which would indicate spark is jumping rather than following the wires to the plugs.

[edrach]

500 rpm is NOT normal rpm for your car. 750 is about right; and I can't imagine it running at 300. Mine idles just fine at 750 to 800; when it drops slightly below 700 it gets rough.