1998 Ranger 2.5L: Spark Plug Torque given alot of rust, NGK vs Ford setting

[rnsc]

After 21 years and about 210,000 miles, just took out what are clearly original equipment plugs and wires. Tons of rust (Plugs and surrounding them, shattering when I break it loose), center electrode just a pointy nub, ground electrode eroded back so that it is not above the center electrode. About 0.090 gap.

Which brings me to torque. I know most people do it by feel, but I got into trouble doing that on a subaru, so now I torque them.

Two questions.

(1) Ford in the big green 1998 ranger workshop manual volume 1 page 202-07A-8 says to torque them to 9-20 Nm (84-180 lb-in).

NGK gives a similar range (10-20) for Aluminum heads, but says 15-25 for Iron heads. These are Iron heads! I I followed NGK I would be using the Iron head column. Which should I use?

(2) Given all of the rust to overcome, should I shoot on the high side? I normally torque to the mid-point (I would do 15 lb-ln or 20 lb-in depending on the answer to #1, but should I go a little higher due to rust grinding? These of course are taper plugs.

Thank you!

--Ray

 

[black_demon69]

most people don't bother using a torque wrench on spark plugs.. just use good and snug spec. it has always worked for me.. might try either cleaning engine or use penetrating oil. it does help to get rid of as much debris as possible around spark plugs...

 

[Dirtman]

Clean the holes and threads out the best you can and use anti-seize on the new plugs. 10ft pounds sounds like more than enough torque to me. But I have never torqued a spark plug in my life.

 

[black_demon69]

case

Clean the holes and threads out the best you can and use anti-seize on the new plugs. 10ft pounds sounds like more than enough torque to me. But I have never torqued a spark plug in my life.

case and point