Can't get spark plug washers to crush

[y_p_w]

I recently installed some NGK platinum plugs in my wife's Civic, but then realized that the beam torque wrench I used had units in N*m and in-lbs. I was thinking the ft-lbs spec in the owner's manual, but was looking at the N*m gauge. So I took them out and realized they were somewhat loose. I got curious and looked at the plugs, and the washers looked like they did new. When I pulled out the factory-installed plugs, their washers were totally compressed and couldn't get any flatter.

So I did it again this morning to about the spec'ed 18 N*m or 13 ft-lbs. I pulled them out again and the washers still looked uncompressed. Does the washer really need to be squished or is can there be enough tension if it's properly torqued?

Am I doing something wrong? I was also thinking that I wasn't using the beam torque wrench correctly. I guess you're supposed to balance the handle so that force is only applied at the pivot point at the end of the beam. Still - I kept on trying and couldn't get to the point where I could get the washer to compress. I was even tightening it beyond a point where I wasn't comfortable beyond that point. I really didn't want to strip the threads. I'm thinking of just finding my clicker type torque wrench, which should be a lot easier to figure out.

 

[AandPDan]

You don't need to crush the washer. The idea is to compress the washer. There is a difference.

Just torque it to the proper spec and leave it.

 

[mount]

These aren't an oil drain plug.

2 types of spark plugs:
Tapered Seat
Washer Sealing

The more you take a spark plug in an out, the greater of a chance you're going to ruin the threads in the head. Torque it to the best of your ability with your torque wrench and forget about it.

 

[Drew99GT]

Yes, the washer needs to be crushed/compressed all the way for the plug to be seated all the way and transfer heat to the cylinder head so it doesn't get too hot. This is why I don't use torque wrenches on delicate items like spark plugs; you get absolutely no feel at all with a torque wrench.

When you install a new plug that has a crush gasket, when you thread the plug in by hand, you'll feel it bottom out and you can't thread it anymore. Then you put a socket wrench on it and it should turn about 3/8 of a full rotation to compress the gasket using light to moderate force on the socket wrench. Stop after that. If you can't compress the crush washer with a torque wrench, something is drastically wrong because it hardly takes any effort to crush the washer with a regular 3/8 socket wrench.

 

[KrisZ]

Simple rule to remember with plugs, tapered type: 1/8 turn past contact, gasket type:1/4 turn past contact. If you're hitting the torque spec at about 1/4 turn then the plugs are torqued properly.

 

[ARCOgraphite]

This doesn't make sense to me that the washers were not crushed. Do you have the correct spec plug in there? I feel crush washers are a one-time deal if you wish to prevent cylinder head distortion (on pentroof cambers) and concomitant valve seat distortion.

 

[The Critic]

Try the NGK recommended torque spec of 18 ft lbs.

I have a good in-lbs torque wrench that you can use if you're interested.

 

[y_p_w]

Originally Posted By: ARCOgraphite
This doesn't make sense to me that the washers were not crushed. Do you have the correct spec plug in there? I feel crush washers are a one-time deal if you wish to prevent cylinder head distortion (on pentroof cambers) and concomitant valve seat distortion.

Absolutely the correct plug. Same NGK part number as the factory-installed plugs, although the factory ones say assembled in the US, while the replacements are made in Japan.

It seems really weird. I've installed plugs before, including using the one-time crush of the washers without a torque wrench, and they were completely flattened when I removed them later. For these plugs I've even tried flattening them with a socket wrench to the point where it won't budge unless I'm willing to risk damaging the head. Then when I remove it, the washer looks totally unsquished. It's like it's springing back to its original shape or something. The factory plugs were completely flattened at the washer.

I'm wondering if it might just be user error with the torque wrench and me being hesistant to really crank it. I'll probably just try the clicker torque wrench and call it a day once it stops. My biggest worry is that I'm going to find a plug launched past the ignition coil.

And just as a point of reference, the handle is supposed to remain more or less centered at the beam, right? I didn't quite understand that, but it makes sense to me now that someone applying force too close might be getting a low reading. I suppose a clicker type wrench is probably more foolproof since it breaks away based on the actual torque at the head rather than based on deflection of the entire length of the beam.

 

[Chris142]

Just crank em in with a ratchet. When you feel them hit the washer go another 1/2 turn

 

[antiqueshell]

Originally Posted By: Chris142
Just crank em in with a ratchet. When you feel them hit the washer go another 1/2 turn


Also to give a description first hand thread the plug into the head, then when the washer makes contact with the head (feel resistance by hand...attach a 3/8" ratchet to the plug...Slowly tighten, you will feel slight increase in resistance when the plug is correctly tightened to near spec...this USUALLY is 1/2" or less of a turn with your ratchet. Point is you will feel the crush washer deforming as you turn the ratchet to tighten then you will feel a bit of increased resistance, STOP turning just AFTER you feel that increase in resistance.

 

[yonyon]

..if you like simple:
Screw it in until it feels tight and then leave it there.

 

[Tegger]

Originally Posted By: y_p_w
And just as a point of reference, the handle is supposed to remain more or less centered at the beam, right?

Your description is a bit confusing, but I'm going to decipher is as meaning: Before any force is applied to the wrench, the pointer and the beam ought to be parallel, and the pointer should line up with the zero on the scale.

Originally Posted By: y_p_w
I didn't quite understand that, but it makes sense to me now that someone applying force too close might be getting a low reading.

I think your problem may lie in not understanding the concept of torque over time. The washer takes time to crush. You don't just go to 13 ft-lbs then stop. The first indication of 13 is premature, because the washer has yet to crush fully. You need to keep pulling on the wrench, letting the washer slowly crush and the wrench go around and around until the reading starts to go up again. The reading will stall at some figure for quite a while before the washer bottoms and the reading starts to increase again.

If you have any experience or feel for the machinery, you will be able to tell very readily when the washer has bottomed, as turning effort will suddenly increase, and the wrench's reading will stop following the beam around and around.

Pull the wrench slowly, like about 2-3 seconds to go 90 degrees, and give the washer time to flatten.

 

[Tegger]

Originally Posted By: Tegger
you will be able to tell very readily when the washer has bottomed, as turning effort will suddenly increase, and the wrench's reading will stop following the beam around and around.

One small addition I need to add separately because my edit-time has expired...

"At that point, you will be able to hold the wrench at the 13 lb reading and it will not drop anymore no matter how long you hold it there."

 

[y_p_w]

Originally Posted By: Tegger
Originally Posted By: y_p_w
And just as a point of reference, the handle is supposed to remain more or less centered at the beam, right?

Your description is a bit confusing, but I'm going to decipher is as meaning: Before any force is applied to the wrench, the pointer and the beam ought to be parallel, and the pointer should line up with the zero on the scale.

No. It's a beam type torque wrench with a handle that sort of pivots on a pin where it's attached to the "lever". I could never quite figure out why it needed that, but now I realize that it's to apply force only at a specific point (the pin) where the deflection is calibrated. I used to just turn this handle until it pressed against the beam. This one has the pin at the center of the handle:

 

[Merkava_4]

I guarantee you that washer would be crushed by time I got done with it. I don't use a torque wrench on spark plugs. I torque them by feel with an 11 inch long ratchet. When the spark plug is tight and the ratchet is not turning any further, I stop. I use torque wrenches on things that compress a lot, like soft gaskets. Things that I can't feel when they're tight is when I'll use a torque wrench.

 

[yonyon]

Originally Posted By: y_p_w
It's a beam type torque wrench with a handle that sort of pivots on a pin where it's attached to the "lever". I could never quite figure out why it needed that, but now I realize that it's to apply force only at a specific point (the pin) where the deflection is calibrated.


It really doesn't matter. You can let the handle pivot any which way you like during use. You just need to apply your force further out than the pointer and the whole handle is past the pointer. If you're checking the calibration you may need to apply a known force at the pin.

 

[Tegger]

Originally Posted By: y_p_w
It's a beam type torque wrench with a handle that sort of pivots on a pin where it's attached to the "lever". I could never quite figure out why it needed that, but now I realize that it's to apply force only at a specific point (the pin) where the deflection is calibrated. I used to just turn this handle until it pressed against the beam. This one has the pin at the center of the handle:

Nice little bit of flash (I'll bet they charge more for that), but not necessary for what you're using it for.

The important things about any torque wrench is that you
1) pull slowly and steadily, and the same way each time, and
2) you grip the wrench by the handle only when tightening.

Go back and read the longer of my two previous replies.

 

[y_p_w]

This morning I tried again. The clicker torque wrench clicked way early. I suspect it's not terribly accurate near the bottom range. I tried the good and tight method (until it felt like I was going to break something) with my ratchet and pulled them. They seem to flatten a bit but not completely flat. I've done this before, although it was quite a while. I seem to remember that these things crush pretty easily. There seems to be something odd about these washers. I tried the beam again and it seemed really odd.

In the end I just did it "good and tight" with the ratchet and called it a day. I'm sure I didn't destroy the threads, and the big worry I have is that they shoot out of the block.

 

[Tegger]

Originally Posted By: y_p_w
and the big worry I have is that they shoot out of the block.

If they're not tight enough, this may eventually happen, with disastrous consequences.

You never did read my first reply, did you? In that reply I told you how to torque properly.

 

[y_p_w]

Originally Posted By: Tegger
Originally Posted By: y_p_w
and the big worry I have is that they shoot out of the block.

If they're not tight enough, this may eventually happen, with disastrous consequences.

You never did read my first reply, did you? In that reply I told you how to torque properly.

I did try that. In that case I could tell it was bottoming out, and the needle kept on going higher on the dial.

I'm pretty sure they're on tight enough. There's just something odd about the washers on these plugs, like they're not soft enough like I'd expect from a crush washer. My first experience with installing plugs on an '89 Integra was pretty easy. I got standard NGKs and didn't have a torque wrench. I just turned them until they contacted, then turned them another half turn (as their diagram showed) and called it a day. When I pulled them out to install new plugs, the washer was noticeably flat.

I'm thinking of just reinstalling the old plugs, since they had about 65K miles on them and were in good condition. The washers were about as flat as they could get, and I figure they should properly tighten with a torque wrench.