1994 Exp. XL Spark plug problem...

What's weird is the hole for the plug. It seems smaller than the bulge of the FM as well as the old PP... I have no idea what is wrong with this. Is that possible that they've made different block with smaller holes? The old PP bulge seem to be machined to fit there as well.

"Mark Stewart" a écrit dans le message de news: snipped-for-privacy@news.easynews.com...

OK - I give - what is the "bulge" in your sparkplug? The threaded end? the tip?

There are only a couple different commonly used auto spark plugs. So, the diameter of yours won't be any different.

Did you put the old ones back in? And what does it look like when you compare the old ones to the new ones? You should be able to compare all the qualities of the plugs to see if they physically are the same, with the exception of the coatings or materials used in the plug construction.

Dave

The yellow line on your picture of the spark plug is the seat that contacts the outside of the cylinder head. It is not supposed to go inside anything. It is supposed to seal against the outside of the head.

The spark plug should thread easily into the hole and when the seat contacts the head you should tighten the plug to the manufacturer's torque spec. If you have changed a lot of plugs, you will know how tight that is without using a torque wrench - if not, best to get out the wrench.

Dave

I can only screw 3/4 turn before it sits on there. I'm guessing it should screw more than this because the old one was screwing lot more than that. I can't run with plug screwed only with one thread.

"JustMe" a écrit dans le message de news:_eIoc.4251$ snipped-for-privacy@fe2.columbus.rr.com...

I bought them at my Ford dealership. As I wrote previously, Motorcraft changed the AWSF42PP by the AGSF42FM. The PP is no longer available but Mark Stewart had the same plugs and he went without any problem putting those on. I'm currently running with the old plug but there about to be completely done so I stay close in town... I'm very confused and I have no clue what to do with this.

"Big Shoe" a écrit dans le message de news: snipped-for-privacy@4ax.com...

construction.

This was an option I thought and I think I'm gonna follow your idea of bosch. I don't see anything else I could do instead of that. How many miles you run with the Bosch?

"Big Shoe" a écrit dans le message de news: snipped-for-privacy@4ax.com...

Do you have the Bosch plugs number by chance?

"Big Shoe" a écrit dans le message de news: snipped-for-privacy@4ax.com...

Do the old plugs thread easily into the cylinder head in the cylinder you can't thread the new plug into?

Did you try more than one of the new plugs in the head?

If yes to both, it would sound like somehow you have the wrong plug. But you should be able to lay the threaded ends of the old and the new up against each other to check for dimension and thread count.

If you have just tried one plug, or the old one won't screw easily into the hole, it sounds like the one plug has its threads bunged up.

If the old plugs still work, it would have to be the new ones that are a problem. If the Ford dealer is not convenient, go to a reputable auto parts store and buy the new ones there.

Dave

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