How to check plug wires

[CorvallisBMW]

What's the "proper" way to check the plug wires for proper working condition? Ohmeter?

[MNE30]

Just use a Multimeter and set it to Ohms and put one lead on one end of the wire, and the other lead on the other end.

I'm not sure how many Ohms you will be looking for, but they should be consistent. I'm actually buying my E30 tomorrow morning and it needs new leads so I just did this with the P/O trying to diagnose the bad spark issue it has.

[bmwstudent]

simply hold and crank, but get video.

[jlevie]

A good rule of thumb is that if the wire (and distributor cap/rotor) have 10yr/100k on them, they need to be replaced.

[long tall eta]

simply hold and crank, but get video.

student is correct. the only way we can help is by holding the wires and getting video.

[E30Gus]

in for the video

[AndrewBird]

Just touch each when to your tongue with the engine running. Like you would with a 9v battery. ;-) Get video of course.

Bentley should give specs on resistance readings.

[wakeboardr42393]

I would say leave it if it's running fine.

That being said, my grandpa has told me that if you get the car to idle, and spray water on the plug wires while the car is running, the car will noticeably misfire if the wires are bad (because the water causes the electricity to arc through tiny cracks/splits/damage and such in the wire before it reaches the spark plug. this damage should not be there. if the wires are not damaged or dry-rotted, they should'nt arc through, and the water should not effect anything). Try not to get the distributor cap area wet if you do this.

Also, I'd say do a good visual inspection. if you see dry-rotting or any splits/cracks, the rubber feels brittle, or if the boots are damaged, replace them.

[bmwstudent]

on a more serious note, I believe there is an ohm spec per foot. I can't remember from school if it was 20-30 ohms per ft or 200-300 ohms per foot. Check a couple and compare. But my first answer would provide more fun for all of us.

[CorvallisBMW]

My tounge? Are you sure? I thought the proper way to check for spark was to hold the plug against my testicles... ;)

[bmwstudent]

so you do know what your doing.