Rick's Free Auto Repair Advice

How to replace Subaru spark plugs the easy way

Replace Subaru spark plugs the easy way with the right tools

Late model Subarus can pose serious access challenges when it comes time to replace spark plugs. The Subaru shop manual tells you to loosen the motor mounts and raise the engine to get enough space to replace spark plugs. You can do that if you want, but there are easier ways; you’ll just have to invest in some special tools that’ll pay for themselves the very first time you use them.

You need a new ratchet to replace Subaru spark plugs

There’s very little space between the valve cover and the frame rail on late model Subarus. So you need a ratchet with a low profile head. Snap-on makes the best low-profile ratchets if you want to take out a second home mortgage.

Fortunately, there are affordable alternatives. Astro Pneumatic and Tone have released reasonably priced ratchets. They’re actually 1/4″ drive ratchets heads that have been retrofitted with 3/8″ drive components. So you get the smaller ratchet head but with 3/8″ drive. See the difference.

The Astro 93808 is 8″ long ($15 on Amazon.com) and the Astro 93812 is 12″ long ($26 on Amazon.com). The TONE RH3CH ratchet is 5.7″ long ($36 on Amazon.com).

subaru ratchet for spark plugs
astro nano ratchet
You need the right spark plug sockets to replace Subaru spark plugs

Subaru spark plugs need either a 14mm or 16mm socket. The spark plugs are longer than normal plugs so you’ll need new sockets. Plus, since they’re buried deep in the spark plug tubes you want a socket that doesn’t have a rubber insert. Those can slip out of the socket and get stuck on the spark plug deep in the spark plug tube seal.

To fix that, the tool companies have come up with several new designs. Some spark plug sockets have clips that snap onto the hex flats of the plug. Other companies use magnets to hold the spark plug. Still others taper the spark plug socket so it tightens onto the plug’s hex flats.

©, 2023 Rick Muscoplat

Posted on by Rick Muscoplat



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