2002 S60 torque for installing new spark plugs (w/antiseize)

coded9 · Post by **coded9** » 14 Oct 2015, 17:17

Ok so this is my first time doing a spark plug change (and first post on MVS) and I kinda have an Idea of what I should do (thanks to a few good write-ups I found on here and other places) but I'm lost on how much to torque plugs when I install them. My manual specifies 21.8 ft/lbs for torque specification, but I'm reading that if I'm using anti-seize on the plug threads I will need to reduce the torque setting. The big question here is by how much should I reduce the torque? The maker of the packet I bought (Permatex Anti-Sieze) specifies to use normal torque values, and most sites specify between 10% and 40%. I'm a bit lost on how much I should reduce my torque since I definitely don't want to under-tighten it, or over-tighten it.

Also any pointers on how I should use the dielectric grease on the spark plug coil boot? I want to make sure I apply the grease correctly so I don't mess something up.

Post by **oragex** » 14 Oct 2015, 17:39

Screw them by hand and when the washer touches down, turn 90 degrees with the ratchet. If the plugs are to be removed later on, I will tight them about 15-20 degrees because the washer is already crushed.

Post by **regent** » 14 Oct 2015, 18:16

I apply a very thin film of DE grease to the inside of the rubber boot where it will contact the plug insulator - just enough to facilitate install and removal of the boot, and some to the periphery that contacts the well in the head. Make sure the coils, boots, and plugs are kept clean to preclude surface arc-over and subsequent misfire.
When applying anti-seize, I only put a small amount on the first 2-3 threads and clean off any excess.
Cleanliness in the 'High Voltage Department' goes a long way

coded9 · Post by **coded9** » 20 Oct 2015, 11:49

Ah ok I see, thanks for the tips. When I read that the anti-sieze changes the torque I got a bit worried since I didn't have too much else to go by other than the manual. Yeah, I've been told there's some kind of feel to tightening it when it comes to tightening the plugs, Maybe I'll see understand a bit more when I (eventually) get around to changing my plugs. Sounds like the boot grease is pretty cut and dry on applying, wanted to make sure there wasn't anything specific there. Thanks though!

Post by **regent** » 21 Oct 2015, 10:22

coded9 wrote:...there's some kind of feel to tightening it ...

Oh well… the designer of the first car ever to be invented did not have much to worry about torque specs either…
Everything was done by feel, including wheel alignment.

Post by **abscate** » 31 Oct 2015, 05:09

Generally fasteners get about 30 % of the tightening tension from thread friction, which lube essentially eliminates. Thus, on lug nuts, I lubricate and reduce torque by 30%

I don't do the same with spark plugs. I lube, start by hand, the tighten with a 6 inch handle firmly with a nip that I probably have developed over the years. Not too useful but it is what it is. I use light oil as lube by the way, no metal paste or stuff like that

45 years and many hundreds of plugs...no leaks, strips, or other issues

It's a car, not a neuron. This topic gets more written on it than it needs, frankly.

Post by **oragex** » 31 Oct 2015, 14:53

regent wrote:
coded9 wrote:...there's some kind of feel to tightening it ...
Oh well… the designer of the first car ever to be invented did not have much to worry about torque specs either…
Everything was done by feel, including wheel alignment.

Run flat tires

Post by **regent** » 31 Oct 2015, 15:08

oragex wrote:
regent wrote:
coded9 wrote:...there's some kind of feel to tightening it ...
Oh well… the designer of the first car ever to be invented did not have much to worry about torque specs either…
Everything was done by feel, including wheel alignment.
Run flat tires

Oh, the RFTs, of course... and what about the suspension and steering?

Post by **oragex** » 31 Oct 2015, 15:17

regent wrote:
oragex wrote:
regent wrote:
Oh well… the designer of the first car ever to be invented did not have much to worry about torque specs either…
Everything was done by feel, including wheel alignment.
Run flat tires
Oh, the RFTs, of course... and what about the suspension and steering?

Zero body roll

coded9 · Post by **coded9** » 10 Jan 2016, 16:51

I know it's been a while since I posted this, I finally got around to changing the plugs. I'm a bit worried I messed something up. I followed the steps (I think) to make sure I didn't cross thread, and I think it might be ok on that it turned smoothly most of the time. As far as torquing the plugs I probably did a bit more than I should (it stopped around 95-100 degrees) on most of them, but as tight as they were coming out I don't think I could've done worse. Only thing is I did find a bit dirt on some of the cylinder heads when I used a light. I took care to make sure nothing fell in from outside (tried vacuuming but it didn't work for stuff that were around sides, I was afraid to risk spreading it in cylinder), it probably happened while taking the old plugs out some of those wells were pretty dirty on the sides. some say I would be ok if it's a bit, others say not. Should I be worried about that bit or no? I started it and it seems fine