You can count me as one of those who uses a torque wrench on his spark plugs, and everything else that has a torque specification. In my humble opinion, torque specs are there for a reason, even when you use a crush washer.
Torque specs for things like spark plugs and drain plugs are based on the assumption that you will be using a fresh crush washer each time you install them.
I find it ironic that those who say you don’t need a torque wrench for this job are quick to criticize those who don’t use a torque wrench on oil drain plugs and lug nuts.
If you’re replacing the back spark plugs on a V6 engine, and it requires a U/swivel joint and extension to gain access to the spark plugs in order to remove/replace them, how are you going to be able to use a torque wrench to tighten them? A torque wrench can’t be used in conjunction with a U/swivel joint because it results in false torque readings. A torque wrench only gives an accurate reading when it’s in perfect alignment with the spark plug.
Or do you not change the spark plugs because a torque wrench can’t be used?
If my spark plugs were that hard to get to, I would hire a professional to change them.
I do a lot of DIY maintenance, but I know to hire a professional when I am in over my head.
For someone who chooses to do this himself/herself, using a torque wrench on the first three plugs can give the person an idea of how tight the other three should be.
Whitey, I’m Not Able To Use The Link You Provided. I Agree With You On Using A Torque Wrench In Most Instances For Tightening Fasteners (Nuts, Bolts) Properly.
However, I choose to carefully tighten plugs (oil drain, spark, etcetera) by hand. They are plugs, not fasteners, like lug nuts. They are not connecting pieces together. They need be tight enough to seal, yet not fall out. An experienced hand is much better for this delicate operation.
The only way to develop an experienced hand for feeling when a plug is tight enough is by expeience and I recommend that you try and learn as has been suggested. I suppose you can check your work with a torque wrench until you get a feel for it if you’d like, being careful not to over do it.
It has been my experience that torque specs for plugs are often high enough to damage threads and at least high enough to be too tight.
I can’t get your link to download on my computer, but I would hope the wrench you bought can be read from top and bottom, both. Most transverse V-6 engines would require the use of a mirror to read a scale on the back plugs and that’s not desirable.
Many engine configurations are just not suitable for a torque wrench at all - it won’t fit - and many require tricky arrangements of wrenches just to change plugs and are not suited to a torque wrench.
Knowing my luck, I would “get a feel” for it by stripping them. In my opinion, it just isn’t worth the risk.
No, the torque wrench I linked is only readable from the top, which works just fine for my I-4 engine.
I get what you are saying about my method not working well on a V-6, but if I had a V-6, especially a transverse-mounted one, I think I would farm out that type of job, like I do valve adjustments and carburetor work on my motorcycles and timing belt jobs on my car. I try hard to work within my limits.
I agree with Whitey. Once the front plugs are installed using a tirque wrench, a “feel” can be gotten of roughly what to use for the rear banks. Use this “feel”. It’s not perfect, but better than not using a torque wrench at all.
Interestingly, I changed plugs for decades not using a torque wrench for plugs, but after having heard so many stories of stripped threads I’ve starting advocating them.
Somewhat reluctantly I will step back into this developing controversy to say that it seems those who have an innate mechanical ability and have made use of it, whether professionally or recreationaly, often gain a self-confidence in their abilities and righfuly so it would seem. Every conceivable style and size of torque wrench of the most trusted brands are at arms reach yet they are rarely used. There are more variables involved than the torque specs. How many thermostat housings have been broken on Fords tightening them with a torque wrench? How many newly installed V8 intakes leak after careful torquing of the bolts? How many spark plugs have stripped out after being torqued to spec? Often there is more success with close attention to the work and results and less attention to measuring to the Nth degree. If the untalented and inexperienced wish to install an intake on a small block V8 they might ask for some advice and the torque spec would be the least important information.
Rod Knox, you make a good point. Spark plugs and lug nuts are supposed to be installed dry, without lube.Thats where the over torque comes into play.Is it common sense to lube these items? Yea, if you have the experience to hand torque them. I’ve trained alot of novice mechanics. My advice is “Damage control”, as the young Techs are scared to death of leaving something loose, so they tighten the ever living crap out of something, only to have it strip.