Team3S Logo, 5k jpg
New York - Munich - Portland - San Francisco - Seattle - Stockholm - Vancouver - Zurich

FAQ: How to Change Your Spark Plugs {1}

'How-To' by Jeff Lucius

Red Gradient Line, 1k GIF


If you have about 3 to 4 hours of time, basic mechanical skills, and a few tools, you can change, re-gap, or inspect the spark plugs yourself. You can use the money you save by not paying a dealer to buy a good torque wrench and socket set. These are my modifications to Brian LaFuente's (GT-Pro) advice. The front plugs are easy and obvious. The back plugs can be accessed by tilting up the plenum; the throttle body and all hoses are left attached. Start at the back of the plenum and work forward. You will need 10, 12, and 13 mm sockets, 5/8" spark plug socket (with rubber insert to grasp plug), a flexible socket extension (like a little universal joint), 3" and 6" socket extensions, screw drivers, some wire, long needle nose pliers or forceps, a torque wrench, and a little patience.

Red Gradient Line, 1k GIF


    1. Disconnect battery negative terminal (10 mm).

    2. Disconnect the Y-pipe from the throttle body. This may require loosening or removing the two intercooler pipes attached to it, depending on your setup, and the air by-pass hose.

    3. Remove the rear IC pipe completely for more working space and stuff clean rags into the top of the turbo and the open IC pipe.

    4. Remove the bolt (12 mm) holding the oil supply line near the rear turbo for more working space.

    5. Remove the accelerator cable bracket (two 10 mm bolts) and set aside. Note the tension of the cable and/or the location of the bolts in the bracket for the installation later.

    6. Remove the two (10 mm) bolts that hold the 3-plug bracket on the passenger side of the plenum. Remove the two bolts that attach the injector wiring harness to the plenum.

    7. Remove the passenger-side bolt (13 mm) from the EGR pipe (it comes up from the rear cat near the oxygen sensor). Loosen (but do not remove) the driver-side EGR pipe bolt, and slide the metal gasket downward. Securely attach a wire to the gasket (forceps can help with this), then remove the remaining EGR pipe bolt. Set the gasket aside; it can be reused.

    8. Carefully remove the two bolts (12 mm) attaching the rear of the plenum to the stays (brackets).

    9. Remove the three (12 mm) bolts from the plenum front, the two long (12 mm) bolts from the plenum top, and the two (12 mm) nuts from the plenum front sides. The plenum may pop a little with the release of pressure.

    10. Lift the plenum straight up to clear the front studs then tilt toward the passenger side. Prop it up with something. A foot-long 2x4 works perfect. The fuel pressure regulator hose will probably slide off the throttle body, but the rest of the hoses (including the clutch vacuum assist hose on the right side of plenum) should have enough length to move the plenum around without a problem.

    11. Cover the intake manifold with a clean rag. You definitely do NOT want anything falling in there. Now is a good time to replace the gasket if it needs it.

    12. Remove the wires from the plugs. Note the routing through the brackets. They are of different lengths and not easily mixed up.

    13. Clean and vacuum the plug areas to remove dirt and oil. You do not want anything falling into the cylinders when the plugs are removed.

    14. The front plugs are easy to remove. The back ones may require moving the plenum around some. I like to note which cylinder each plug comes from for the next step.

    15. Do what you need to with the plugs. Now is an excellent time to inspect the plugs for color, oil, damage, burns, and detonation specks (you may need a magnifying glass). This can tell you how each cylinder is performing. If changing the gap, be careful to not damage the platinum tips. Stock gap is 1.0-1.1 mm (0.039-0.043"). The proper spark plugs are platinum NGK PFR6J-11 (or Denso PK20PR-P11 or equivalent) for the DOHC engine, and NGK BPR5ES-11 (or Denso W16EPR11 or equivalent) for the SOHC.

Red Gradient Line, 1k GIF

If you are replacing the wires too, note the following arrangements:  The cylinders are numbered from the driver-side (timing belt side) of engine as1, 3, and 5 for the front bank, and 2, 4, and 6 for the rear bank. The connections to the ignition coil use the following order, from the front of the car, 6, 3, 5, 2, 4, and 1. There are three coils with the following cylinder pairs firing at the same time 1-4, 2-5, 3-6. Firing order is 1, 2, 3, 4, 5, 6.

Red Gradient Line, 1k GIF


    1. Install the plugs and tighten to 25 N-m torque. Tip: barely slide the plug into the socket just enough so that it won't fall out. Gently insert the plug and tighten a little by hand. Then remove the socket, the rubber insert should still be in it. After all plugs are started, remove the rubber insert from the socket and complete the tightening process, first by hand, then with a torque wrench.

    2. Securely reattach the plug wires noting the proper routing.

    3. Remove the rag covering the manifold and the prop and lower the plenum onto the manifold studs (with a new gasket if needed). Do NOT attach bolts or nuts at this time. You will need the plenum loose for the next step.

    4. Bolt the plenum to the rear two stays first. You may need to apply your weight or tap the plenum with your fist to get the holes to line up. Be sure to reattach the grounding cable and oil pipe bracket with the driver-side stay. Insert the two bolts by hand and tighten but do not torque down.

    5. With the wire still attached to the EGR pipe gasket, insert the driver-side bolt through the EGR pipe and gasket into the plenum. Tighten a little by hand. Remove the wire, slide the gasket around, and insert the other bolt. The bolts can now be tightened (18 N-m).

    6. Install the front five plenum bolts and two nuts. Torque the two rear stay bolts, the front five bolts and two nuts to 18 N-m.

    7. Now proceed with removal steps 6 to 1 above (in reverse order of course). Be sure to check the fuel pressure regulator hose and the other vacuum hoses. The disconnected battery will reset the ECU. Let the car idle a few minutes and check for leaks or other problems.

Red Gradient Line, 1k GIF

e-mail us at...

Feedback?Questions? Comments?

Red Gradient Line, 1k GIF

3D & Ram Logo anim, 6k GIF

Team3S FAQ Page


Article 2000-2004 Jeff Lucius, All Rights Reserved.
All Images 1995-2004 Bob Forrest, All Rights Reserved.