19' Forester - What tools do I need to change the spark plugs?

Subaru Forums Subaru Forester
1

Hey everyone,

I’m planning to replace the spark plugs on my 2019 Subaru Forester. I’ve heard I might need a wobble extension and a special spark plug socket, but I’m not sure if that’s all. Any advice or tips would be appreciated!

Thanks, and Happy Thanksgiving!

2

image
image430×435 57.6 KB

3

Koken Tools is currently running a black friday sale, and they make my favorite tools for this job.

First, you’ll need a 14mm spark plug socket – I’m very fond of 3300CZ-14

Second, yes you’re going to want a couple of wobbly extensions to make life easier, and again Koken has excellent offerings. You can get the full set if you want, but the 50mm and 75mm are the two lengths I use for spark plugs.

For a ratchet, you do want something with a relatively thin head – I invested in the Matco frankenratchet from MrSubaru but really any 3/8 drive ratchet with a flex head and some length to the handle would do. I used the classic Gearwrench 90T for a long time beforehand, and I still use a Tekton as my go-to hand ratchet these days. When doing spark plugs, I’m really only using the ratchet to break loose (and to final torque tighten) the plugs; the knurling on those koken extensions makes it easy to just spin the plugs out by hand once loosened.

There are a couple other things you’re going to need:

  1. You’ll want a standard-depth 10mm socket for the ignition coil bolts. (You don’t need to disconnect the electrical connectors from the coils, the boots will flex I promise, just push them out of the way toward the rear of the car)
  2. You’ll need a way to remove the battery, which probably means you’ll need a 10mm wrench of some flavor and a deep 10mm socket for the nuts on the tie-down rods
  3. You’re going to want to remove the bracket that holds the positive battery cables to the frame rail. For this, I use this [very fancy snap-on flexy socket](https://shop.snapon.com/product/Extension-Sockets---Swivel-Ball%2C-mm%2C-Industrial-(3%2F8"\)/3-8"-Drive-6-Point-Metric-10-mm-Swivel-Ball-Extension-Power-Socket/PFSXM910B) but you could probably accomplish this with a shallow 10mm and those wobble extensions at home. The 2 bolts you need to remove also have philips crosses cut in the top, but I wouldn’t recommend trying to remove them that way. Once the bolts are out, you can lift the bracket upward and bend it a little until it rests on top of the fuel pump protective cover.
  4. On the passenger side, life is going to be a lot easier if you remove the air filter housing. You’ll need an 8mm something to remove the band clamp (personally I prefer a nut driver so you don’t over-torque it on install) as well as the same long extension setup you used on the battery cable bracket in step 3.
4

@Macon
I’m pretty sure theyre jis not philips

5

Haven’t done them on a forester, but on my old wrx and 12 Legacy, access is limited, particularly on the drivers side. I found that in addition to the spark plug socket (I like them to protect the insulator) I used small extensions I could put in one after the other to get the length I needed helped - I don’t usually use a wobble for that. Looks like a similar issue for my current car (24 Legacy)

6

@Indy
Your '24 will be a bit more challenging than both your EJ-powered previous cars :slight_smile:

7

Macon said:
@Indy
Your '24 will be a bit more challenging than both your EJ-powered previous cars :slight_smile:

Ugh. I was thinking it looks about the same as my old 12 LGT - does the giant harness on the side of the engine not move or something? I was sort of hoping it was just pull the battery, shift the harness and proceed as with the old car… (current car has the FA24)

8

@Indy
Ah the 2.4 is actually slightly easier than the 2.5, basically it’s the same just the access on the driver side is even tighter

9

Bare minimum I use a 3" wobble extension with a 14mm spark plug socket. You can use a regular socket also, just be careful cause you can damage the plug if done improperly. Also need a short 10mm socket for the coils. You might want to remove the battery for more space on the driver side, so a long 10mm socket for that. And you’ll need to remove half the airbox for the passenger side, so a flathead screwdriver for the hose clamp.

10

1/4" drive 10mm ratchet with short socket to get the coils out of the way.

I use a 14mm spark plug socket with 1" extension and a swivel joint. (all 3/8 drive) sometimes moving the air cleaner housing and battery out of the way will help.

11

Watch this guy’s video.

It helps to have a really flat or low profile wobble wrench and a very long socket.

I didn’t have that, but I had a magnet to retrieve anything that might fall down the hole (like the socket I didn’t fully connect).

12

@T.gwendew
What magnet tool do you have if not minding I ask?

13

Milan said:
@T.gwendew
What magnet tool do you have if not minding I ask?

Thus guy

https://www.autozone.com/test-scan-and-specialty-tools/magnetic-pick-up-tool/p/duralast-led-magnetic-claw-pick-up/1266537_0_0?searchText=Magnet+grabber