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My civic has 100,250 miles and the service came up for the spark plugs. B124, I am reading and it says after replacing the plugs to torque it to 13 Lbs. The only torque wrench I have is minimum 15 LBS. Would this be too much torque? What are the chances that I strip the threads?

RobNav
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While it most likely will be OK, it is not worth the risk. If you do over torque the spark plugs and strip the threads you will regret it because it will be a big job to get it fixed.

Most mechanics will probably not use a torque wrench for changing the spark plugs, but they have had years of experience and know just how tight to make them. What you will be doing is definitely going past the manufacturers specifications.

If you do want to do the job yourself and dont want to get another torque wrench, use the torque wrench you have on another bolt until it clicks so that you get a feel for what the 15lb/ft feels like. Then tighten the spark plugs using what you feel is a little less force so that the torque wrench doesn't click.

HandyHowie
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The lower and upper ranges of the torque wrenches are generally unreliable. With a bit of bad luck the deviation of the torque wrench is too large for the threads.

I'd consider getting a smaller wrench, as a min. 15lbs wrench is a fairly big tool.

Martin
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Given that there will be at least 5 or 6 full turns, the likelihood of stripping threads even at higher torques is unlikely. However, having changed thousands of sparkplugs, I've never ever used a torque wrench. Generally, plugs will have a crush ring, which is there for a purpose. Tighten, probably by hand, even, until that is reached, then turn another 45-90 degrees. That will allow the crush washer to do its job. I say by hand, as most stripping is caused by the first turn or two, when something is crossthreaded, and force is used to get it in.

Tim
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No - you'd have to stop tightening before the first click. If it clicks then you've over torqued it.

Another option is to "calibrate your elbow" by paying attention to how much force it takes to remove a spark plug. Using the same tool to reinstall should get you close enough, as long as you use about the same amount of force.

Two downsides, you're installing new plugs that may be less-smooth threads, and you're turning in the other direction which makes it harder to gauge. I work around the second when doing wheel lug nuts by always lifting up from the ground, and always kneeling.

Criggie
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You can use any wrench really. The torque wrench just makes it quick and easy to get the right amount of force.

Foot/pounds: The foot part refers to the length of the handle, the pounds part refers to the amount of force.

So for your plugs apply 13 lbs of force 12 inches from the center of the socket. Or 26lbs of force 6 inches from the center of the socket. I find a simple hanging spring scale works well for the measurement part when I'm doing something outside the range of my torque wrench.

You can also use what one of my great uncles called the "jeweler's touch". As you tighten a screw thread the amount of force needed to turn it just a little more does not go up linearly. If you tighten the plug slowly you will feel a sudden jump in the amount of force required when all the threads are fully engaged. For the vast majority of applications that's where to stop. Practice on something else of similar size a few times and you'll get a feel for it. Like others have mentioned, most spark plugs need to be just a tiny bit tighter than you can get them with your bare hand.

Perkins
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