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Spark plug torque?

path1
Explorer
Explorer
Forgot torque it's been so long. Any know correct torque?

Onan micro quite 4000 gas
2003 Majestic 23P... Northwest travel machine
2013 Arctic Fox 25W... Wife "doll house" for longer snowbird trips
2001 "The Mighty Dodge"... tow vehicle for "doll house"
8 REPLIES 8

K_Charles
Explorer
Explorer
The onan book says 7 to 18 so they don't think it's a big deal. I would go half way between snug and snap.

fj12ryder
Explorer II
Explorer II
Lynnmor wrote:
Be careful using anti-seize on spark plugs, especially in aluminum heads. Many engine and spark plug manufacturers do not recommend it. Here is just one video explaining the problem.

video
They recommend against it because of user error. Not any inherent problem with anti-seize. And it probably isn't as necessary as when heads were made of cast iron. I always use a dab and I've never had an issue with plugs coming loose, or worse, not being able to remove them. But it's just like Brylcreem.
Howard and Peggy

"Don't Panic"

Lynnmor
Explorer
Explorer
Be careful using anti-seize on spark plugs, especially in aluminum heads. Many engine and spark plug manufacturers do not recommend it. Here is just one video explaining the problem.

video

Flyfasteddie
Explorer
Explorer
I'm sure there is a torque spec, but standard procedure for 14mm/18mm plugs is finger tight then 1/16 of a turn for tapered seat (no gasket) or 1/2 turn for one with a (new, not already tightened) gasket. Not sure what size that plug is, but 10mm=1/4turn & 12mm=3/8turn.

mike-s
Explorer
Explorer
Mechanic's feel. You'll feel an increase in torque when the gasket touches and starts to compress. Torque until you feel another increase - that means the gasket is fully compressed, so stop there. Maybe ~1/4 turn at most?

Only works with new plugs - on old ones, the gasket is already compressed, so the 1/12 turn is probably right.

fj12ryder
Explorer II
Explorer II
If you start at 12 and torque to 10, you'll be way too tight. You're going clockwise remember. Start at 12, and 1/2 flat will be 1. That sure seems like it wouldn't be anywhere near tight enough, or maybe I'm looking at it wrong?
Howard and Peggy

"Don't Panic"

path1
Explorer
Explorer
Thanks for responding. Your method is new to me. Is your method a "general" guideline for all plugs? Sounds pretty good to me. Am I interping right in my mind if I...

Finger tight then apply torque to plug to 10:00 position (assuming my starting position is 12:00 position?
2003 Majestic 23P... Northwest travel machine
2013 Arctic Fox 25W... Wife "doll house" for longer snowbird trips
2001 "The Mighty Dodge"... tow vehicle for "doll house"

Matt_Colie
Explorer
Explorer
For gasketed plugs, 15~20#ft is good, but you really want to do is just touch the gasket and then turn 1/2 a flat (30ยฐ). Anti-seize will life easier then next time.

Matt
Matt & Mary Colie
A sailor, his bride and their black dogs (one dear dog is waiting for us at the bridge) going to see some dry places that have Geocaches in a coach made the year we married.