Plug Wire check

[Composedflame]

I recently purchased a 1985 325e in running but slightly rough shape. I've been driving it for about a week and a half and its proven quite entertaining as all I have previously owned has been an auto Camry.

Anywho, for about a day now its been refusing to start. I began following the Bentley's checklist and upon pulling off the plug wires and examining the spark plugs (probably should have done this before problems arose) I noticed heavy amounts of corrosion on the contacts between the plug wires and the spark plugs. The plug wires were not firmly "on" the spark plugs and I couldn't seem to get them on as there was no snapping or clicking on like all previous cars I've seen.

The previous owner had replaced the plug wires and spark plugs roughly a month before I purchased the car. Leading me to believe he could have purchased the incorrect plug wires but I found the same Bosch plug wire set for sale at several online retailers.

Main question: how are the plug wires supposed to connect to spark plugs on an '85 eta? Do they just slide on or should there be a more secure connection?

[Sagaris]

I have had 2 sets of aftermarket 8mm plug wires from reputable sources. Neither of them fit securely on the plug or gave that audible *click*. The last set I had (which was replaced under warranty) had 2 wires that an infant could pull off, they just sat so loosely. Those 2 did develop corrosion, but the engine ran normally with only a very faint power loss on those two cylinders, nothing any ordinary person would detect. you can apply some di-electric grease to the top of the plug before inserting the boot to help avoid corrosion. As long as it is not misfiring or popping off altogether then you are in good shape. If the looseness worries you, then get OEM wires from an OEM supplier or the dealership (gonna be very pricey most likely).

I would check into some other factors for your car such as

Checking for spark while cranking and proper fuel pressure will go a long way in narrowing down the problem.

We could compile a list of possible problems, but I personally feel that this ^ would be your best starting point.

[TimR]

Most Spark plugs come with a small threaded end, this must be removed for BMW wires to attach, look closly and you will see. It feels like the wires are sliding on the plug threads as you push them on.

[PNWDan]

Most Spark plugs come with a small threaded end, this must be removed for BMW wires to attach, look closly and you will see. It feels like the wires are sliding on the plug threads as you push them on.

^^this^^