Plugs with crush washers can feel deceptive when installing them. When the crush washer makes contact with the seat, you will feel resistance (this is probably where you got nervous and stopped tightening them). You then want to keep tightening until you feel a significant amount more resistance, which may take another complete turn or so. It feels like you’re doing terrible things to the threads, but it’s just the crush washer compacting. Snug it down another 1/16 of a turn or so after you hit the significant resistance and you are good to go. I did a set of these crush washer plugs a couple weeks ago for the first time in five years or so (none of my personal vehicles use them), and the first one made me a bit nervous since I hadn’t touched one for quite some time. They feel so wrong going in.
I am also in the no torque wrench for spark plugs camp. I have never used a torque wrench to install spark plugs, and the only person I have personally witnessed use a torque wrench on spark plugs was my father, when he tore the threads out of the head on my younger brother’s first car “helping” him do a tune-up.
I used a torque wrench on my spark plugs until I was confident I knew what it should feel like. After that, there was no need. I suspect others learned a different way, and don’t realize there are several ways to arrive at the proper destination.
Personally, I always use a torque wrench on plugs - I simply don’t have to change them often enough, and I have a tendency to underestimate the amount of torque I’m applying when doing it by hand. If I target 7-13 lb-ft, I’m just as likely to hit 20 as I am 10. I set the torque wrench on the low end, apply to get it to click, then double-check the torque.
Thank you all for the comments. This is the first time I’ve installed these iridium plugs with the washers. All of my other cars have been fine with a 1/4 turn.
So I feel like I have no common sense, I checked to see if they were loose after reading the # 4 middle front plug comes completely loose in my 2005 Accord V6 - went to check them and it was pretty loose. Tightened them all with a significantly larger amount of force and then was told to not leave them in there too long or be sorry later.
Got a torque wrench that I’ll barely use, set it to 13 ft lbs per Honda. Loosening them up even after tightening them very hard was again extremely easy and… tightening them to 13 lbs barely feels like I’m tightening them at all.
I’m going to trust the torque wrench, but am I missing anything? Would there be a differential in torque after I’ve messed with them so much?
(also just to gripe, the clip to my # 4 coil pack was always kind of iffy and didn’t click, and this time broke off - coil pack is fine but still annoying)
You should not have any problems if 13 foot pounds was used. If the torque wrench is 18" long, it will feel like you have done no work at all. We used to have to change plugs at 10 to 20 thousand miles and only had problems after 100,000 miles. Not true but most cars were no trouble.
I think you’re right, i’s just the longer/bigger wrench. I set it to 15 lbs just to make sure they were tight. Seemed to drive fine this morning and so I’ll just watch out for the rough idle.
100k on plugs sounds good until you realize there’s less room for error on tightening them.
Please don’t feel like you have no common sense. These things have to be learned, and you’re doing great. I wish everyone had enough sense to ask and to double check.
Re: the cllip. Just a tip. Automotive clips are designed such that a backward facing “hook” will clip to a retainer “hook” when installed. The best way to prevent breaking the clips is to push them in before pushing the little side lever that disengages the “hooks”, then pull them out.
Oh, and I also bought a needle nosed pliars and bent the tips in just for using on automotive clips. It works great.
When I first started wrenching I never used a torque wrench…mainly because I couldn’t afford one. As I started to do more complicated projects the need for a torque wrench became necessary…so I saved up and bought one. I hardly ever use it now.
Thanks for the TSB. It makes sense that no additional anti-seize is needed beyond the chromate conversion coating. I’ll change the plugs in my 2005 Accord EX soon, and will likely use the NGK plugs, too. My Accord has been a great, reliable car for me. I’ve got about 96000 miles on it. How has yours been?
I want to second what ts mountainbike said about your questions. There is a big difference between being uneducated and dumb. Your questions clearly point out that you want an education, and that’s smart.
Having done more maintenance on light airplanes than cars, I ALWAYS use a torque wrench, out of habit.
I use Champion aviation thread lubricant (high temp graphite) on my automotive plugs. I’d hate to be in a position of having to put in a helicoil because I overtghtened. But that’s me.
If you’re going with hand tightening there are charts to indicate how much past hand tight you should go. There are different turning numbers depending on type of plug (tapered seat vs washer seat) head metal (aluminum vs steel/cast iron) etc.
I would’t go as tight as this suggests though. Maybe 1/4 turn…
and… tightening them to 13 lbs barely feels like I’m tightening them at all.