The most difficult plugs I have ever removed, ever, were on my 2004 Volvo V 70 R. OEM Volvo, a unique plug for that cylinder head. Whoever installed them, roughly 30,000 miles prior, had used antiseize. The regular aluminum anti seize.
The anti-seize had turned into almost locking compound under the heat of being run in the engine.
They were extraordinarily difficult to get out, I had to work them back-and-forth, and I used penetrating oil and let them soak overnight once they were loose.
Still, they were difficult to get out. The torque was at least three times what it would normally take to break a plug loose.
While the car was sitting in the shop overnight, with the penetrating oil, I was online, shopping time-serts that would fit in Volvo cylinder head. They were that bad. I thought I was bringing the cylinder head threads out with them.
Maybe they used way too much, I don’t know, but I do know that antiseize in this case was a detriment. I’ve pulled a lot of plugs out of a lot of aluminum cylinder, heads, and this set was by far the worst, and I ended up having to chase the threads once they were out.
So, no, I’m not necessarily a fan of anti seize. If the manufacturer recommends it, I’ll use it, but on spark plugs, I tend to use copper, or nickel, and never the cheap aluminum stuff.
I have checked the gap on every Iridium plug I’ve ever installed. They’ve always been spot on. I have to wonder if that’s because folks are using aftermarket plugs on some applications. I don’t know. I’ve never had to adjust the gap on Iridium plugs on a Mercedes, Volvo, or Toyota.
I’ve had to do a lot of gaps on the old style plugs. But those were copper core, regular plugs. In the days of 302 Ford, V8, or 400 small block Chevys, yeah, sometimes they came out of the box and needed to be tweaked, but it’s been a long time since I’ve had to adjust a spark plug gap.
NGK makes the spark plugs for both of my V-12 Mercedes. At 2 plugs per cylinder, with 12 cylinders, that is 24 spark plugs when you do a change on just one of those cars. That’s a lot of plugs, and they’re not cheap.
With the expense of the job, and the several hours of labor to get the coils and intercoolers off, you can bet I am following manufacturer directions to the letter. And I’m using a good quality torque wrench to ensure that every one of those 24 spark plugs is properly, consistently, torqued.
since you don't have compression washers. With compression washers, it is smart to use a torque wrench. On the Kona forums Bosch denied a new $10,000 motor to guy who stuck Bosch (should of been NGK or Denso in my book) because the compression washers where not fully compressed and the electrode/porcelain dropped in the cylinder during use. Even though he said he torqued them. We don't know if they would of warranted it even if they were crushed correctly. Just saying.
. Spark plugs get installed dry on everything made in the last 30 years. Anti seize can cause misfires and can actually make removal harder.
