Correct Spark Plug Type

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Oct 2, 2018 | 04:26 PM

Tom Evans

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Joined: Jan 2016

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Correct Spark Plug Type

I have a 2007, Ford Explorer with the 4.6L V8. I currently have Motorcraft SP-514 spark plugs in it. From a number of parts catalogs, it looks like the SP-547 is being recommended for the replacement of the SP-514.

What have others found out about these two different spark plugs? And which do you recommend?

Thanks.

Dec 12, 2018 | 04:27 PM

spikedog

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From: Wyoming

I just put in a couple of Autolite HT1 plugs to replace 514 plugs in my 06 Explorer 4.6L. I put the 514's in at 100K, and one of them was trash at 145,000 miles. The metal arch was gone as well as a chunk of the ceramic insulator. The HT1's look very similar to the 514 plugs. Both of the 514's came out of the head OK; I'd had 3 of the OEM plugs break on me. I did add the nickel antiseize application at 100K.

Neither the HT1 or SP547 plugs look like one piece plugs. It's hard to tell just what's going on with the Motorcraft part numbers. Half the references call the 547's out as original equipment and no longer manufactured, and the other half say the 547's supersede the 514's.

As long as you have the plug extraction tool available when you change plugs, and do the nickel antiseize application, I think you'll be OK.