And that is one of the reasons I prefer electronic torque wrenches
No ambiguity
lights AND beeps
18-22 is more than enough to pull threads if half a dozen ham fisted people have had their hands on the plugs in the past. In over 40 years I’ve never pulled threads yet or had a plug come loose although I have had to repair many aluminum head plug holes because of prior ham fisted events. I assume my Snap-On torque wrenches are reasonably close, but…
Many plug makers spec for this sans torque wrench. Copy and pasted below.
Without a Torque Wrench:
If a torque wrench is unavailable, finger tighten the spark plug, then use a plug wrench to tighten.
Autolite -For spark plugs with a gasket: 1/4 turn on 10mm plugs, 3/8 turn on 12mm plugs, 1/2 turn on 14mm and 18mm plugs. 1/16 turn on plugs with a tapered seat.
Bosch - 1/4 turn on plugs with a gasket. 1/16 turn on plugs with a tapered seat.
Champion - 3/8-5/8 turn on plugs with a gasket. 1/16 turn on plugs with a tapered seat.
Denso - 1/4-1/2 turn on plugs with a gasket. 1/8 turn on plugs with a tapered seat.
E3 - For spark plugs with a gasket: 1/2 turn on 10mm plugs, 3/8-1/2 turn on 12mm plugs, 1/2-3/4 turn on 14mm plugs. 1/16 turn on plugs with a tapered seat.
NGK -1/2-2/3 turn on plugs with a gasket. 1/12-1/8 turn on plugs with a tapered seat. Without a Torque Wrench:
Thx for the replies guys…
Update: I pulled one of the new plugs (NGK) out, measured the gap and it showed 0.03 inches.
I checked the gap on the old plug (Bosch) and it showed 0.042 inches. My car’s specs on the hood shows as shown in the attached image…
The 3 numbers don’t match at all unless I am reading the hood sticker wrong…
There’s a typo on the sticker. .7mm = .028", not .0028". Your gap of .030" on the new plugs is right in the middle of the range.
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Thanks… so gap is not the problem then…
Update: I replaced all 4 plugs with the original old ones. The sparky noise is still there… I guess the next step is to change the wire set, which I will have to order online…
That old plug you pulled with the .042 shows just how much the electrode can wear away with spark plugs… The gap is ever widening in essence…
I would bet that the noise you are hearing is emanating from one of the plug wells…the part of the wire that actually snaps onto the top of the plugs gets cracked over time…and its surrounded by a perfect environment to tempt an electric arc to jump (that being the metal plug well walls)… this is a common event if you change enough spark plugs, so dont rule it out. Either way arcing from the wire casing or plug boot…we are talking about a new set of wires at the end of the day basically. No big deal…and an oft ignored component. People seem to think wires last forever…they dont.
Also I have never used a torque wrench on plugs myself. My torque wrench is my hands for anything less than head bolts these days. So I think I am with @ok4450 on not using a T wrench and the feeling or reason behind it, but… to each his own.
So should I use compressed air to clean/blow out the well?
It’s a good idea to use a torque wrench the first couple times just to get a feel for how tight they should be. Then a torque by feel.
Another reason I do not trust torque (other than God knows how much wear and pull on the threads has happened over 30 years in this case) is that the torque figures often have a wide spread.
I’ve seen 10 to 24, 15 to 27, and 16 to 28 for instance. That’s a shotgun approach to me.
Plugs in my aluminum head Lincoln engine call for 7 to 15. So which one? Too much of a variation for my tastes.
Use the compressed air only while the plugs are installed.
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