Mazda3 2.3l Oil Change

Oil change time! Yup. Very exciting. But I’m always surprised when I encounter a “car guy” who doesn’t change his own oil. It’s such an enjoyable little ritual. Paying the high school kid at Zippy Lube to over-tighten your filter just seems like cheating.

So hit the print button, bring this how-to out to your garage, turn on the crappy garage radio, and get your hands dirty.

Stuff needed:

  • A Mazda3 oil filter. I’ve got the 2.3 with the cartridge, so I need part L321-14-302-9U from Mazda. That comes with the two required o-rings and the filter itself.
  • 5 quarts of oil. Mazda calls for 4.25 quarts of 5w20. I like Mobil’s products. Feel free to pick anything. I don’t wanna start this with an oil debate.
  • The big oil filter socket. Since I’ve got the previously-mentioned cartridge filter, I use the huge socket that Mazda sells. I think it’s 76mm?
  • Oil pan
  • 10 and 17mm sockets. Socket wrench. And torque wrench.
  • Set of metric allen wrenches. I think you’ll need the 6mm wrench.
  • Gloves and paper towels.
  • A jack and jackstand or ramps.

Disclaimer: I am not ASE certified, nor Mazda certified, nor a real mechanic. I’m just a car guy who likes to blog. If you get hurt, I claim no responsibility.

Jack up car - install jack stand

Step 1 - jack up the car and install the jack stand.

My Mazda3 is tall enough that I can get by with a single jackstand under one side. I like to put it as you see here, under the A-arm mount. Ramps work too.

Pull off the engine cover.

Step 2 - Pull off the plastic engine cover.

You can do this with your hands. Pull from the back. It’s held in by the two pegs in the back with the arrows and one at the front. You can also unscrew the oil filler cap at this time.

Remove belly pan

Step 3 - Remove belly pan.

This is a little bit annoying. The belly pan is held in with seven (7) bolts with 10mm heads. Three in the front, and two on either side. I think the car also came with a few of those plastic retainers that you have to pry out with a screwdriver? I never reinstalled those after removing them the first time. I just trust in the OVERWHELMING amount of bolts to hold the pan in place.

Remove drain plug and drain oil

Step 4 - remove drain plug and drain oil.

The oil drain plug is on the back of the engine. 17mm bolt head. Very easy to find once the pan is out of there. Drain the oil out.

For the oil draining, I remove the jack stand and put the car back flat on the ground. This gives you a little more complete flush. And, to go back a few steps, I always drive the car around a few miles before starting this job to warm the oil up a bit. Warm oil drains better than cold oil.

Inspect the drain plug washer

Step 5 - Replace the drain plug washer.

I’m 90% sure that the drain plug washers come with the filters when you order them from Mazda. The official line is to change the crush washer every time. I’m guilty of not doing that. You’re an adult and can make that choice for yourself. Officially: change out the crush washer.

When the oil has finished draining, jack the car back up and reinstall the jack stand. Reinstall the oil drain plug. Torque to 22-30 ft/lbs.

Time to fiddle with the oil filter

Step 6 - deal with the oil filter cartridge.

Notice the socket head bolt in the middle of the filter housing? That’s the drain plug. As I said before, I think it’s 6mm. Unscrew it and a small amount (but not all!) of oil will come out. Move your pan accordingly.

Told ya it was a big socket

Told ya it was a big socket.

Once the oil has slowed, attach the big socket and unscrew the oil filter. More oil will be left in the base, so be mindful. I only splashed it all over my shirt once.

Stuff needed for step 7

Stuff needed for step 7.

This is all included in the box from Mazda. You get a clean and shiny filter cartridge, a small o-ring, and a big o-ring. The small one goes on your cartridge drain plug. The big one goes on the cartridge itself.

Swap out the drain plug o-ring

Step 7a - Change the cartridge drain plug o-ring.

The small green thing at the base of the plug? That’s the o-ring. Swap it out. And around this time is when I like to take off my gloves for some reason.

Change out the filter cartridge

Step 7b - Change the filter cartridge itself.

Old and busted goes away in favor of the new hotness. If you’re especially bored and/or crazy that day, you could cut apart the filter cartridge and see if there are any particles trapped. I always just toss it.

Clean filter and new o-ring installed

Step 7c - Install the new cartridge o-ring.

Don’t forget the big o-ring. This goes around the base of the cartridge. Looks good all clean like that, eh?

Reinstall the cartridge filter with the big socket. Mazda’s torque spec is 22 ft/lbs. Be careful over tightening as everything is made of plastic.

Remove the big socket and reinstall the 6mm filter drain plug. The torque spec is 7.6 ft/lbs. I’m guilty of just tightening it “enough” with the allen key.

Fill it up with oil.

Step 8 - Add oil.

Yes. The end is in sight. Just add oil and you’re good to go. The factory spec is 4.25 quarts. I add 4 quarts and then start the engine. This lets some oil circulate.

Turn off the engine and wait a couple minutes for the oil to drain back into the pan. Check the dip stick. Add any oil required to bring it up to full.

Reinstall the belly pan. Put the car back on the ground. Go for a test drive.

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  • mazda3 says:

    […] Mazda3 2.3l Oil Change ? […]

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    • revlimiter says:


      I’ve had my site running steadily since 1998. I’ve had lapses of interest, but I’ve kept the domain name active. It should be here for a few more years…

  • pharmacy tech says:

    What a great resource!

  • Leila Zamora says:

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  • Good article. I’ve favorited this blog so I can follow your follow-ups. Thanks for taking the time to share this.

  • Peter says:

    I’m not understanding why more than one person posting an oil change guide takes the engine cover off. I didn’t need to. Access to both dipstick and filler cap are fine. I have a 2009 3s. Are they different?

  • Kenny says:

    I also have a 2.3L Mazda 3. Have you considered the oil filter conversion kit? It allows us to use the same spin on filter that the 2.0L Mazda 3’s use. I find it alot more convenient than the cartridge factory setup.

  • Matt says:

    I also pre filled the new oil filter with new oil. 🙂
    Thanks for the torque settings.

  • harga terbaru mazda says:

    Great paintings! That is the kind of info that should be shared around the internet. Disgrace on Google for not positioning this publish upper! =)

  • Ian says:

    Nice article. I found it after writing my own article doing the same thing this weekend! Anyway, nice pictures and thanks for sharing.

    I had a little tip – cut the service hole in your belly pan a little larger. I did this to my Mazda3 on the first oil change and it’s saved me some totally-worth-it time.

    Check it out here

  • Tim says:

    I enjoyed your article, thanks so much for the torque specs

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