2.5l Engine Spark plug DIY
Vehicle: 2013 Outback (timing chain endgine)
Difficulty level: 2 out of five bloody knuckles.
My general takeaway: I can only use my own experience changing plugs on other cars as a reference: This job is way easier than doing spark plugs on a Camry V6 engine which can take hours. But the plugs/coils proximity to the inner frame makes it a fiddly job. To be honest, I was originally concerned that I would need to jack the engine up to clear the inner frame, but that is not the case.. With the right tools, it’s a breeze.
The annoying part is that the space is so tight that you cant just jam a spark plug socket, extension, and socket wrench into each hole all in one shot. You are constantly assembling/disassembling in order to feed the tools in/out of the tight space.
Here’s a good primer video with the basics of spark plug removal for cars with aluminum cylinder heads:
Tools: (From left to right)
• 3/8 socket wrench
• 14 mm Spark plug socket (note: you really want to use a spark plug socket that has the little rubber insert. Otherwise, a regular socket will undo the plugs, but will not extract them from the rather deep cylinder head. I did not have one in my tool set, so I removed the rubber insert from a 5/8 spark plug socket and stuffed it into a regular 14mmdeep socket.)
• 10mm socket
• 10-inch 3/8 straight socket extension (optional)
• 3-inch wobble extension (note: this may be the second-most important tool to have. Having the wobble head on the extension gives you more leeway to work around the edges of the frame. I tried doing one plug with a regular 4-inch straight extension, and it was very clumsy work).
• 1-inch 3/8 extension (optional)
• flat head screwdriver
• Dielectric grease (not pictured) Here on Amazon
• Iridium Spark Plugs (not pictured) NGK Silver Iridium here.
NOTE: I could not find my little 1/4 socket wrench at the time of this job. If I did have it available, I would have used it and a 2-inch extension for all of the 10mm bolts and nuts. It would have been much easier that way.
Replacing the Spark Plugs
1. Disconnect wires to each of the coil packs.
2. Use 10mm socket to remove the only bolt on each coil pack. (optional: Once you break the bolt loose, disconnect the wrench and use the 1-inch extension on the 10mm socket to run the bolt out by hand. It’s way faster).
3. Pull each coil pack off. It may take some wiggling as you back the coil off the spark plug. Take your time. Those things are expensive to replace.
4. Spark plug removal:
_____a. Slide the spark plug socket (alone) into the cylinder head.
_____b. Slide the 3-inch wobble extension into the spark plug socket.
_____c. Make sure the socket is seated on the spark plug.
_____d. Attach socket wrench, and gently loosen the spark plugs. Remove the socket wrench from the extension when you start bumping into the inner frame.
5. Put a dab of anti-seize grease on the treads of the new plugs.
6. Put a dab of dielectric grease inside the rubber hole of the spark plug socket, and then . (The grease will help the socket release the spark plug once everything is tightened down. Otherwise, the socket might stay in the cylinder head when you try to pull it out. Ask me how I know this!)
7. Thread the spark plugs in by hand. Once they are hand tight, use the socket wrench to give the plug another ¼ turn.
8. Reinstall the coil packs
9. Reconnect coil wires
10. Reinstall 10 mm bolt to hold coil packs in place. Tighten them to “snug” (translation: don’t go crazy).
General Tips:
1. I found it very difficult to extract the socket/extension from the driver’s side rearward spark plug hole, because I kept bumping into an aluminum A/C line that’s attached to the inner frame. I solved this by gently removing the AC line from its plastic clip and moving it about an extra ½ inch out of the way. Make sure you reconnect the aluminum line when you are done.
2. The passenger side plugs require you to remove the air intake. Here are the steps.
_____a. Disconnect the wire to the MAF sensor located near the air filter housing.
_____b. Use flathead screwdriver to loosen the ring clamp on the air inlet tube where it connects to the air filter housing and the throttlbody.
_____c. Pry up the plastic fastener that holds the air inlet tube to the throttlebody. Remove air inlet tube, and set it aside.
_____d. Pry loose the fasteners that hold the air intake on the front radiator support. Disconnect the air intake from the air filter housing.
_____e. Open the air filter housing, and loosen the 10mm nut that’s hiding in the upper edge (secures it to upper radiator support).
_____f. Use 10 mm socket and 10-inch extension to remove the bolt that holds the airfilter housing to the inner frame.
_____g. Move the air filter housing out of the way, to gain more access to the front spark plug coil.
_____h. Put it all back when you’re done AND BE SURE TO PLUG THE WIRES BACK INTO THE MAF WHEN YOU”RE DONE.
While You’re in There:
Here are some other maintenance jobs that you can plan on doing during this job.
1. Clean MAF Sensor: https://www.subaruoutback.org/forum...rself-illustrated-guides/55657-diy-gen-4-maf-mass-air-flow-sensor-cleaning.html
2. Clean Throttlebody
3. Replace Air Filter
Vehicle: 2013 Outback (timing chain endgine)
Difficulty level: 2 out of five bloody knuckles.
My general takeaway: I can only use my own experience changing plugs on other cars as a reference: This job is way easier than doing spark plugs on a Camry V6 engine which can take hours. But the plugs/coils proximity to the inner frame makes it a fiddly job. To be honest, I was originally concerned that I would need to jack the engine up to clear the inner frame, but that is not the case.. With the right tools, it’s a breeze.
The annoying part is that the space is so tight that you cant just jam a spark plug socket, extension, and socket wrench into each hole all in one shot. You are constantly assembling/disassembling in order to feed the tools in/out of the tight space.
Here’s a good primer video with the basics of spark plug removal for cars with aluminum cylinder heads:
Tools: (From left to right)
• 3/8 socket wrench
• 14 mm Spark plug socket (note: you really want to use a spark plug socket that has the little rubber insert. Otherwise, a regular socket will undo the plugs, but will not extract them from the rather deep cylinder head. I did not have one in my tool set, so I removed the rubber insert from a 5/8 spark plug socket and stuffed it into a regular 14mmdeep socket.)
• 10mm socket
• 10-inch 3/8 straight socket extension (optional)
• 3-inch wobble extension (note: this may be the second-most important tool to have. Having the wobble head on the extension gives you more leeway to work around the edges of the frame. I tried doing one plug with a regular 4-inch straight extension, and it was very clumsy work).
• 1-inch 3/8 extension (optional)
• flat head screwdriver
• Dielectric grease (not pictured) Here on Amazon
• Iridium Spark Plugs (not pictured) NGK Silver Iridium here.
NOTE: I could not find my little 1/4 socket wrench at the time of this job. If I did have it available, I would have used it and a 2-inch extension for all of the 10mm bolts and nuts. It would have been much easier that way.
Replacing the Spark Plugs
1. Disconnect wires to each of the coil packs.
2. Use 10mm socket to remove the only bolt on each coil pack. (optional: Once you break the bolt loose, disconnect the wrench and use the 1-inch extension on the 10mm socket to run the bolt out by hand. It’s way faster).
3. Pull each coil pack off. It may take some wiggling as you back the coil off the spark plug. Take your time. Those things are expensive to replace.
4. Spark plug removal:
_____a. Slide the spark plug socket (alone) into the cylinder head.
_____b. Slide the 3-inch wobble extension into the spark plug socket.
_____c. Make sure the socket is seated on the spark plug.
_____d. Attach socket wrench, and gently loosen the spark plugs. Remove the socket wrench from the extension when you start bumping into the inner frame.
5. Put a dab of anti-seize grease on the treads of the new plugs.
6. Put a dab of dielectric grease inside the rubber hole of the spark plug socket, and then . (The grease will help the socket release the spark plug once everything is tightened down. Otherwise, the socket might stay in the cylinder head when you try to pull it out. Ask me how I know this!)
7. Thread the spark plugs in by hand. Once they are hand tight, use the socket wrench to give the plug another ¼ turn.
8. Reinstall the coil packs
9. Reconnect coil wires
10. Reinstall 10 mm bolt to hold coil packs in place. Tighten them to “snug” (translation: don’t go crazy).
General Tips:
1. I found it very difficult to extract the socket/extension from the driver’s side rearward spark plug hole, because I kept bumping into an aluminum A/C line that’s attached to the inner frame. I solved this by gently removing the AC line from its plastic clip and moving it about an extra ½ inch out of the way. Make sure you reconnect the aluminum line when you are done.
2. The passenger side plugs require you to remove the air intake. Here are the steps.
_____a. Disconnect the wire to the MAF sensor located near the air filter housing.
_____b. Use flathead screwdriver to loosen the ring clamp on the air inlet tube where it connects to the air filter housing and the throttlbody.
_____c. Pry up the plastic fastener that holds the air inlet tube to the throttlebody. Remove air inlet tube, and set it aside.
_____d. Pry loose the fasteners that hold the air intake on the front radiator support. Disconnect the air intake from the air filter housing.
_____e. Open the air filter housing, and loosen the 10mm nut that’s hiding in the upper edge (secures it to upper radiator support).
_____f. Use 10 mm socket and 10-inch extension to remove the bolt that holds the airfilter housing to the inner frame.
_____g. Move the air filter housing out of the way, to gain more access to the front spark plug coil.
_____h. Put it all back when you’re done AND BE SURE TO PLUG THE WIRES BACK INTO THE MAF WHEN YOU”RE DONE.
While You’re in There:
Here are some other maintenance jobs that you can plan on doing during this job.
1. Clean MAF Sensor: https://www.subaruoutback.org/forum...rself-illustrated-guides/55657-diy-gen-4-maf-mass-air-flow-sensor-cleaning.html
2. Clean Throttlebody
3. Replace Air Filter
