Worrying about over-torquing spark plugs

[morgant]

I'm overly nervous anyway and fairly anal retentive, so I like to do things by the book, but I've had to close everything up 1/2 way through changing my spark plugs and call it a night (of course, this was the last bit of repairs I was trying to do today and started it in the dark after a couple hours of already working out in the cold... not too cold, about 28°F before the sun set, but cold enough.)

Spark plugs are easy, but I had never attempted them before, and the ones coming out are horrendously fouled, but I'm worrying I've over torqued the first two I've replaced. The old ones (at least the two I've done so far) came out very easily. The Haynes manual specifies 156in/lb torque for the spark plugs, so I set my 10-150ft/lb torque wrench to 13ft/lb, but it's not clicking in what I feel is reasonable amount of torque. It feels I've torqued them well past what they originally were and I stopped where I worry I may have already gone too far.

This is a fairly new torque wrench and it worked correctly when I replaced my thermostat, but maybe 13ft/lb is too close to the minimum. Or, would the fact that it was cold (i.e. the torque wrench had been sitting in my trunk all weekend) make a difference? Or, am I being just completely paranoid?

I've brought the torque wrench in to warm up and I'll finish up in the morning when it's light out, but if anyone's got advice or can help assuage my fears, I'd really appreciate it.

[pdq]

13 pounds with a 1 foot long torque wrench takes barely any pressure to hit. The problem is that your torque wrench at its minimum torque setting doesn't actually click anymore; rather it just "gives" when it hits the limit. If you're curious, try torquing other large bolts to see how the wrench acts when it hits a low torque setting.

If you use a normal wrench, just tighten until then spark plugs are snug, and then a quarter turn is usually sufficient.

If you're worried about overtorquing, back the spark plugs off a turn, and then retorque them.

[morgant]

Originally Posted by pdq

13 pounds with a 1 foot long torque wrench takes barely any pressure to hit. The problem is that your torque wrench at its minimum torque setting doesn't actually click anymore; rather it just "gives" when it hits the limit.

Thanks, that's what I was afraid of.

If you use a normal wrench, just tighten until then spark plugs are snug, and then a quarter turn is usually sufficient.

If you're worried about overtorquing, back the spark plugs off a turn, and then retorque them.

I definitely way over-torqued them.

I'll pull the two I did replace & re-torque them as you've described (which is more like what I was expecting). I certainly hope I didn't damage the threads in the first two spark plug sockets.

You all are always so helpful even when I'm causing my own grief.

[pdq]

I'd bet you're golden after retorquing. Good luck.

[Bitter]

finger tight then about 1/4 to 1/3 of a turn. just enough to seat the gasket, you'll feel it flatten and then the resistance of the threads.