Plug Change, A Major Change?

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David13

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Well, I finally got an air compressor and blew the dirt out around the plugs and pulled one.

Looks very good but very very old, and ... gap of about .060.

So I have no emissions sticker, or one that does not give the plug gap. So, do I go with the .040? Or wider?

Or what? And what will be the consequence?

I know as the plugs age they burn down and widen the gap. So maybe that's what mine were doing.

I guess I just have to go with the .040 and see what happens.

Now, this engine was running good, drove me 100 miles home, went up hill nice. So how could the plugs be that bad?

What can you tell me?
dc
 

LibertyTC

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EDIT THESE Specs ARE FOR A KJ: not what you need for your 2008...
The spark plugs should be changed every 35k miles.
The KJ coil packs fires these plugs very hot, gaps get enlarged due to worn center electrode, taking them out of spec.
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Use the NGK ZFR6F-11G, gap at .040 inch.

Edit: Your 2008 KK needs NGK ZFR6F-11 (Gap.043 in)
 

LibertyTC

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CORRECTION !! You have a 2008 KK me bad..the correct plug is
NGK ZFR6F-11 (Gap.043 in)

David could you add the year of your jeep to the signature line please..
 

David13

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Now I have a kk, is that the same?

Just yesterday I was looking at a thread where you posted that very sticker.

I had searched all over and found the NGK 6987, aka ZFR6F-11G. And then happened to find them at the near local Auto Zone for $2.99, better than I could find on the internet.

The plug coming out is also identical. NGK ZFR6F-11G.

I guess I just have to go ahead and do it. And see how/if it still runs. Then get it up in the air and change oil, filter, atf and filter, front and rear diffs, and transfer case. And inspect everything down there. Then I'll know what I have.
dc
 

LibertyTC

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See post #3 David ^ Your 2008 KK needs NGK ZFR6F-11 (Gap.043 in)

David could you add the year of your jeep to the signature line please..
 

LibertyTC

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I went back to the other KK thread and added 2008-2012 corrections stating KK needs NGK ZFR6F-11 (Gap.043 in) on all the posts to make it clearer.
This now becomes my go to image!
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David13

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Rock Auto and Parks Geek says .044. They come out of the box at about .040.

I have looked around the house and can't find those coin style gauges. I know I had at least 2 of them when I left Los Angeles. I guess I won't find one til after I buy a new one.

Ah, the glove box book. It came with a glove box book and it does list the plugs .... AND THE GAP??!! .043. They say the glove box book used to tell you how to adjust the valves. Today it says don't drink the battery fluid.
dc
 

LibertyTC

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Ya the ole owners manual found in the top glove box area! If in doubt always refer to your owners manual.
Fluid requirements, spark plug specs and much more is very helpful, in the basic manual indeed.
I have both stack-able feeler gauges and the round coin, wire types. Must have back ups ! ;)
 

David13

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Yes, I finally got them all out and new ones in. I did go with the .43, or .043, or .0043, somewhere around there.

And got it all back together and it does run. I haven't put any miles tho'. Maybe 3? I don't want to put much til I have looked at all fluids. And got the wheels off the ground and off and check brakes and bearings. It all seemed good on the test ride and the 100 miles home. But I like to look under there, and rotate tires. That will give me more info about the tpms system. And I'll check the tires. One seems to have a slow subtle leak. I'd like to find that and get it fixed. My spare is shot so I need to get something for that as well.

Glove box book. My opinion of glove box books just keeps going lower and lower. They say years ago the glove box book told you how to adjust the valves. Today it tells you don't drink the battery fluid.

My opinion is that the glove box book says "oh, don't you worry your pretty little head about changing your light bulbs on your Jeep. You take it to the perfessionals at your certified authorized Jeep dealer and let them do it. There are too many hazards involved and you want to avoid that."

Then you take it to the dealer and they charge you a fortune and then screw up something else. Or what they were supposed to do in the first place. There are reasons many people don't call them dealerships, they call them stealerships.

Trust but verify someone once said. That's all I'm doing, just verifying. Which involves learning.
Thanks
dc
 
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