Spark plug only tightening tiny bit

Hey there,

I’ve just changed the spark plugs on my Mazda Premacy. Tightened them to hand tight then used a socket wrench to further tighten them but could only tighten them about 1/16th of a turn before I basically cant turn them anymore or feel like I’ll wreck it if I do. Everything I’ve seen has said 1/4-1/2 a turn so wondering if I’m doing something wrong?

Putting in plugs is fun.

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All 4 are the same, only tighten a bit

Spark plugs with a crush gasket will rotate 1/2 turn after contact. Spark plugs with a tapered seat will only rotate 1/16 turn after contact to tighten.


Do you still have the package the plugs came in, if you do, what exactly is the part number of the plug. Also what year is the Mazda and what engine is in it so we can confirm if you have the correct plugs.

@Nevada_545 is correct except that a new plug with a crush washer is 1/2 to 3/4 turn. The tapered seat is 1/16 to 1/8 turn. If a plug with a crush washer is reused, then it will only turn about 1/8 turn because the washer is already crushed.

If you still have the old plugs and they have a crush washer on them, you may have gotten the wrong plugs this time or the manufacturer left the crush washer off them.