Spark Plugs

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ktm525

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Finally got around to doing the other bank of plugs (passenger) and thought I would toss up a picture of what plugs with 160k kms (100k miles) on them look like. One of the plugs threads had light rust. The tips looked good.

My advice on plugs. Take you time and don't be in a rush. Plan your attack carefully and the job is not too bad. Have lots of extensions for your plug tool.


Finally NGK 6C10 have been superseded by 7C10 which is a different heat range so that is weird.
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Pfunk951

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Well done KTM..

Has anybody done a step-by-step for plugs yet? If not, I'm thinking about doing one- this seems like a job were we could save some folks some money with a few pictures and details..

Mike
 

ktm525

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I believe there is a post somewhere about it. The service manual is not much help, just a couple pictures and that's it. You have to take your time pulling the coil electrical connectors and there is very little room to work in. Imagination and patience will get you to the finish line.

To begin the cover comes off and the two heat shields on both banks of the engine. The air filter boxes come off and then it is a matter of disconnecting the coils, pulling the coils and then replacing the plugs. Probably a 3 hour job if you are taking your time.

Here is a thread about it:

http://www.landroverworld.org/threads/anyone-done-their-own-spark-plugs.26763/
 

gsxr

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Finally NGK 6C10 have been superseded by 7C10 which is a different heat range so that is weird.
I'm finding the ILKAR6C10 for sale at a few different sites, where do you see it being superceded to the ILKAR7C10? Did you buy the plugs from the LR dealer, or aftermarket?
 
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bbyer

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those don't look too bad at all. Nice work.
That is when you want to change the plugs - when they still look good.

Another good reason for changing out the plugs regularly even if they are still OK is that we have aluminum heads - well aluminum engines. Leave the plugs in too long and the engine threads tend to freeze to the plugs and come out with the plugs - they you do have a challenge.

For my 3's 4.4L petrol V8, I change out the plugs, (reinstall factory plugs), every 100,000 km, (60,000 miles) as I am afraid of the cost of the thread thing.

I might add that a friend of mine has a 1990's Thunderbird with the V6 and over 300,000 miles on it. The engine got to running rough so he though he should perhaps change the plugs.

On all six plugs, the gap had burned to more than an 1/8", (point was near even with the insulator), and white carbon was pretty much coneing up to the gouge in the L shaped bit.

While I do not think the Motorcraft plugs had Henry Fords fingerprints on them, they most certainly had Edsel's. They were the original factory installed plugs. While this sort of plug change interval might work for a Ford engine, I do not recommend it for our Jag engines.

And yes, the plugs were the problem - T-Bird runs well now - probably do another three hundred if the body holds out.
 

ktm525

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I have had no issues with NGKs with cold rolled threads welding themselves into the head. My LR3 plugs at 160k kms were a little squeaky coming out while the 4's plugs were fine. The business ends of the plugs were fine and could have probably made it to 200k miles. Changing plugs on the 4 most shops will charge 2-3 hours + $10/plug. Enough to make me adhere to the schedule but not exceed it.
 

ryanjl

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I usually put a little bit of anti-seize paste on the threads when putting spark plugs into aluminum heads.
 

gsxr

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ktm525

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Nice summary. With "flat" bottomed NGK plugs simply spin by hand until they bottom and then another 180 degrees. Done.
 

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