I just bought some new spark plugs for my 02 Civic EX yesterday. Each plug comes with a metal ring, but I’m not sure what this is and where it goes (I’ve never changed spark plugs before). What is this metal ring, and where does it go? I haven’t removed the old plugs, so maybe it is obvious at that point, but I didn’t want to get started until I know what to do with the ring. Any help would be greatly appreciated.
Those metal rings are the crush gaskets. You slip those over the end of the spark plugs so it creates a seal between the spark plug and head.
Tester
Thanks! I thought that was what they were for, but I figured I’d better check before I screwed anything up. I definitely appreciate the help.
Don’t go crazy tightening the plugs, use a torque wrench to specs if you are learning how sung is good, also do not pull on the plug wires, only the boots, there is a tool for cheap if you need one to pry the boots off, and my suggestion is to do one plug at a time so there is no chance of messing up firing order, good luck!
You don’t have to use a torque wrench if you know what you’re doing.
Put some anti-sieze on the threads. Tighten the plugs until they bottom out. Tighten the plugs another quarter turn. That’s it!
Tester
Anti-Seize is a great suggestion, torque wrench suggested as They are doing this for the first time and your advice is good, but they might not even be able to know what you are saying, so better safe than sorry.
Yes, a torque wrench costs less than one striped thread.
The torque wrench required will have to measure in inch/pounds. The cheapest you’ll find is about $50.00. I’d rather use feel than a cheap torque wrench.
Tester
Autozone loan a tool would be free. How do you teach feel over the interweb? You and I know what it means but I feel better suggesting the torque wrench.
Didn’t I say, “Once the spark plug seats, give it one more quarter turn”?
That’s how you install spark plugs with crush gaskets.
Tester
I’d add another vote for no torque wrench. Two points: one, the crush washers make it somewhat more difficult to get an accurate reading with a torque wrench. The torque can increase until the washer crushes and then go down again, which with the low torque specifications on a spark plug can mean that you might be able to reach the specified torque before the gasket crushes, which means it’ll be too loose. Secondly you don’t know 100% that the car actually came with crush washers (well, unless it says so in the factory manual or if you know for a fact the plugs in it are the factory ones) and so if the torque spec is for without crush washers, getting it to the specified torque with a crush washer on is not very relevant.
I think it probably doesn’t matter a lot either way. One other option is just do it the quarter turn method and then put a torque wrench on it to double check (which is generally more accurate than measuring the torque while you’re applying it, especially on a cheap wrench). You’d really have to try at it to strip a plug hole with a fresh crush washer.
I don’t even know one mechanic who uses a torque wrench for spark plug installs. Feel is far more reliable and less prone to stripping threads.
On a side note, I’ve seen specs given that vary quite a bit for the same plug, same car, and same engine. One may state 8 Ft. Lbs and another may state 17. No way would I feel safe twisting a plug in an aluminum head down to 17 Ft. Lbs.
Regarding the gaskets, small diameter edge faces the cylinder head.
OK I am wrong for suggesting a torque wrench for someone who has never changed spark plugs and does not have a clue for feel and should go by what you and tester and greasy have provided.
I think I’ll do the quarter turn method, and maybe check with the torque wrench. I think the manual says to turn it 2/3 of a turn after the plug touches the cylinder head? Is that too much (I’m just wondering if the whole quarter turn thing is fairly universal, or if it varies a lot from car to car)? Also, regarding when the spark plug is “seated”? Would I be correct in assuming that when the plug is as tight as I can get it with my fingers that it is then time to get the ratchet out and do the quarter turn?
I’m a little paranoid about stripping the threads after I did so on an oil pan on a motorcycle a few years ago. Fortunately, fixing that involved just buying a $5 used oil pan and installing it in 15 minutes. I was annoyed at the time, but it was a great lesson for me since the consequences were so minor and I learned to be cautious.
Thanks for all the responses. I’ve always really liked cars, but I really suck at fixing them mostly because I’ve never had many opportunities. Now I’m trying to learn a few things without destroying too much.
Crush gasket flush to the head plus a quarter turn will be fine. Err on the side of caution. The stakes are only high on the over-tightening side. Under-tightening will not be the same kind of disaster. Just snug them that 1/4 turn and then check them for looseness after the first 500 miles or so.
The point being is that when it comes to aluminum, and especially well-used aluminum threads, you really can’t trust it at all.
We had a SAAB in one time for a valve lash adjustment and this thing caused me grief from start to finish.
With this model one has to use special tools to check the lash on all valves. The camshaft must then be removed, shims changed to bring the specs in line with what was written down during the inspection, and everything reassembled. No problem up to this point. The hxxx started when I reinstalled the camshaft and the 8MM cam tower bolts started pulling their threads.
Torque spec was about 18 Ft. Lbs and always erring on the side of caution, I used 15. So back off and install a thread insert. Reinstall and another one pulled. Now I’m ticked.
Back off again and carefully checking the rest of them for any signs of pulling. A second thread insert later and sure enough, when torquing them back down 2 more gave way.
At that point (and in the process of learning new and colorful language) I got mad and installed a thread insert in every one of those holes.
A roughly 2 hour job turned into more like 6.
Tester is correct about an inch/pounds torque wrench. These can be trusted; at least a good one can. I’ve got a high dollar German made one and seldom even use it though.
You could see a lot of kind of thing with the old air-cooled VWs. The nuts that hold the cylinder heads on were supposed to be torqued to about 20 Ft. Lbs and many people could not believe that 20 was near enough to hold the cylinder heads down so they twisted them on down. This led to case stud pulling and trashed engines.
Well, the risk is that someone who’s inexperianced with a torque wrench reads it wrong, holds it wrong or uses a funky combination of extensions or something and ends up putting way too much torque on a plug trying to make the torque wrench read right. Since the extra 1/4 turn is easy enough to describe, I’d say that’s the safer way to do it, especially since torque wrenches aren’t going to be that accurate to begin with at these sorts of lower torque figures.
Why not a metric torque wrench?
I Don’t See The Big Issue Here Being Tightening The Plugs A Quarter Turn After They Bottom Out In Their Holes. That is Important And A Good Strategy, Though.
The real concern here is to get the old plugs out and the new plugs in without stripping threads or getting a plug stuck so that even a pro can’t get it out without forcing it out.
The best possible thing to do would be to work beside someone with experience successfully changing many spark plugs. If that’s not going to happen then I would use a spark plug socket together with a short ratchet handle to get the plugs loose (just until they begin to turn easily). Be sure you are loosening and not tightening.
Once loose, try and turn the plugs out without using a ratchet handle if possible. Light effort with the handle may be necessary. If you’re lucky the plugs will unscrew without major effort. What you don’t want to do is to have a plug bind up and become stuck and continue to force it or have it turn out quite hard and take the threads with it. This is were the pros come in. They have tricks and know how to very often save the task from getting out of hand.
If you stripped an oil drain plug then a spark plug job could go to heck in a handbasket if a plug or plugs resists more than a moderate effort to unscrew. Putting them back, first make sure you have them aligned correctly and then use only the socket, extension, and fingers to get them started and threaded in a ways, if not all the way until they seat. Don’t start out with a ratchet handle or any handle on the wrench.
Go ahead and give them a try, but just in case, if a plug or plugs get tight without coming out I’d see if it will screw back in and get some professional help.
Do you know how long the plugs have been in there (years /miles) ? Sometimes time and miles make them stick, but not necessarily. Oh, make sure the engine has not run for several hours before you begin.
Know your limitations as you work and work slowly without distractions and have patience. You’ll do just fine.
CSA
Regarding torque wrenches in general and on spark plugs in particular, some here have replaced hundreds of pounds of spark plugs and like myself often recognize damaged threads in a head from feel as we remove an old plug. And certainly as has been noted the “feel” of the crush washer can be felt as the plug is twisted to seat, especially if a good socket is used with no wobbles involved. I find it difficult to explain to “fastidious” beginners how to accomplish this and other jobs as the procedure can’t be easily put on the page. All this is to say that some people are just mechanically inclined and have a FEEL for the work while others don’t. I wish I could play the piano and paint but I can’t. But I will remain grateful that I feel comfortable repairing things.