Didn't manage to find a proper guide here on SS on how to swap out old spark plugs (and coil packs) so here's a guide with some (poor quality, sorry, twas taken with a Blackberry..) pics.
DISCLAIMER: This guide is for informational purposes only, and is written based off a 2006 S60R. Your car may require a different procedure. Please attempt procedures with extra care, I am not responsible for your damages. If you do not know something, LOOK IT UP before you proceed. Otherwise
So before we begin, here's a comprehensive list of items/tools you need:
- 5 new Spark Plugs (duh, but please make sure they fit your vehicle, NGK Iridium IX LFR6AIX-11 here)
- Torx Tool T-25 & T30
- Flathead Screwdriver
- Hex-bolt wrench (Not sure of the size, test it yourself)
- Deep hex-shaped tool (5/8 inch size), fitted with a spark plug holder (recommended)
- Spark plug gapper
- Torque wrench
- Keep car off for 3 hours before beginning to work, cuz parts of the car may be HOT, especially when you're from Texas and it's TRIPLE DIGIT temperatures in the summer.
- Anti-seize (0.14z is more than enough, you can get them for $1 from Autozone)
- 5 new Coil Packs (for those who want to replace them only, not required if you're only replacing spark plugs, it can be anything like IPD's HD Coils or VIVAPerformance's Plasma Direct Coil Packs)
1 - White waiting for your car to cool off, check your spark plugs to ensure that they are of optimal condition: no damage to the spark tip, and of the correct gap. The recommended gap from NGK in the S60R is 0.028" or 0.7112mm, use the spark plug gapper to ensure that it's of the right gap.
2 - Begin by opening your hood, and removing the over the engine (OTE) pipe by removing the two Torx T-25 screws on the frontal side of the engine [FIGURE 1, CIRCLED BLUE], and then the two V-clamps on the front and back of the engine with the flat-headed screwdriver (the V-Clamps are a little hard to reach, and be careful of the HOT surfaces when reaching in deep).
3 - Next, remove the blue (stock color), left Volvo engine cover by removing two of the Torx T-30 screws, and popping them off from the front. Then remove the remaining six Torx T-30 on the right Volvo engine cover. [FIGURE 1, CIRCLED RED]
4 - After removing the engine cover, you should see the top of the five coils [FIGURE 2]. I recommend replacing one spark plug at a time. Remove the hex bolt with the wrench [FIGURE 2, CIRCLED RED] off one single coil pack first. Then remove the coil pack by pulling it upwards. Be careful not to damage the coils.
5 - You should be able to see a spark plug located inside. (If you don't, you've been running with one spark plug less! Otherwise consult a psychiatrist) [FIGURE 3]. Use the deep headed hex-shaped tool along with a wrench and twist counter-clockwise (ensuring that the spark plug is being loosened parallel to the cylinder hole to avoid ruining the thread).
6 - At this point, unplug your coil pack if you wish to replace it, and then reattach the new one. Once the spark plug is removed, prepare the other spark plug by adding anti-seize paste to the thread (optional) [FIGURE 4]. Be careful to coat them on the thread only, do not stain the spark plug tip with the paste.
7 - Using the deep-headed hex tool, and using a torque wrench, attach the new spark plug, insert and turn clockwise (torqued to 21.8lbs/ft, recommended). Once tightened, reattach the coil pack and tighten with the bolt you originally removed.
8 - Repeat step 7 for the remaining spark plugs. Once done, reattach the right Volvo engine cover, and then the left, ensuring that they snap into the right place, tightened with the eight Torx T-27 screws. Once done, reattach the OTE pipe, and tighten the Torx T-25 screw first, then the V-clamps. Double-check to ensure that the OTE pipe is tight and in place.
9 - Check that your engine bay is CLEAR of your tools, and that you didn't drop anything inside. Shut engine hood, chug beer, smile.