can you use dielectric grease on coil / plug interface?

[kolosy]

had a really hard time getting my coils to seat back on the plugs. ended up getting it done but wondering if i can lubricate them with something (dreading having to pull those couple next time)

[spammysammich]

I just give the tip of the coil a small spray of silicone

[kolosy]

Originally Posted by spammysammich

I just give the tip of the coil a small spray of silicone

silicone is an insulator though, any concerns about interfering with power delivery?

[spammysammich]

The part of the plug the tip of the coil interfaces with and sticks to is the insulator of the plug. The conductor of the plug is grabbed by the contacts higher up into the coil. Don’t spray in the coil. Just a little into the tip. You basically spray at it at 90 degrees. Not straight into the coil. Been doing this for years with all my cars. Never had a problem.

[kolosy]

doubted myself on the actual electrical characteristics of silicone spray (since it's obv a semiconductor).. found this:

The important issue for us is that silicone can polymerise into hard, brittle material that can cause electrical problems, as well as weld connectors together. Manufacturers and sellers of silicone dielectric oil and aerosol sprays might disagree with us but crucially, the major automotive manufacturers and their tier one suppliers also agree.

https://support.newgatesimms.com/not...al-connectors/

_edit_ posted this before reading your response, that makes sense.

[spammysammich]

I can tell you with 100% certainty that the bmw tech that used to own my car also used silicone spray in a very small amount. My coils came off and relatively easily with out a ton of prying. And he was the one that taught me the trick years ago. Subaru coils can be a bitch to remove without it.

[spammysammich]

Let me be clear. I’m not putting silicone grease on the contacts. I’m lightly spraying a small amount on the rubber boot that grabs the plug insulator. If any got on the actual plug contact it would not be enough to disrupt the signal.

[RocketyMan]

Totally disagree with that article. There are mfgrs out there that solely recommend dielectric grease for connectors/contacts that are especially prone to corrosion. BTW, the links within the article were dead as well. The whole article is more of an editorial than anything else.

What spammy is referring to is the spark plug glass insulator. The grease helps with this as servicing the spark plug is made easier when removing the coil. A little bit on the conductor is OK (this should go without saying not to glob it in there). I've done this myself when changing spark plugs, and I don't need any elaborate "removal tool" such as a coat hanger with risk of braking the coil. -_-

Using the grease also helps aid with installation of the "boot" section going onto the spark plug.

[spammysammich]

I use this to help me pull the coils. I ground a windshield wiper puller down a couple mm to create this puller. Works well except for the two coils near the firewall

[kolosy]

Originally Posted by spammysammich

I use this to help me pull the coils. I ground a windshield wiper puller down a couple mm to create this puller. Works well except for the two coils near the firewall

does that puller grab below the rubber boot at the throat of the valve cover, or does it grab the little rubber hat like the CNC machined ones? i have a CNC machined one which works great on the S65, would love to find something that works on the S85 too (which doesn't have that hat and you have to pull the connector itself which is terrible).

[spammysammich]

It only grabs the top plastic that most machined tools grab. They were NLA when I got my car so I improvised.

[kolosy]

Originally Posted by spammysammich

It only grabs the top plastic that most machined tools grab. They were NLA when I got my car so I improvised.

i randomly ended up with 2 of them fwiw (had one, and one came with the car when i bought it). happy to send you one if you cover shipping from Chicago.

[spammysammich]

Originally Posted by kolosy

i randomly ended up with 2 of them fwiw (had one, and one came with the car when i bought it). happy to send you one if you cover shipping from Chicago.

I’m good thanks. Actually really happy with my improvised solution. And my coils never really give me trouble. I find it also helps to twist the coils a quarter turn or so before trying to pull on them.

[kolosy]

Originally Posted by spammysammich

I’m good thanks. Actually really happy with my improvised solution. And my coils never really give me trouble. I find it also helps to twist the coils a quarter turn or so before trying to pull on them.

really wish there was one for the s85. ended up breaking 3 coils trying to get them out when i got the car. 1 so bad that i had to pull the valve cover off to get it out. sigh.