2016~2023: CX-9 41K spark plug change, found NGK plugs in the wild
- Thread starter MIMazdaowner
- Start date
IIRC, the spark plug holes in the skyactiv engines are deeper, so it's harder to use pliers to pull them out... likewise with putting them in... because these spark plugs have more brittle tips and are expensive, that's a risky thing to doFirst off, I'd definitely consider buying that tool if I was doing spark plugs more often. That said, I've always had an easy time changing plugs using a standard, non-mag plug socket that has no insert. All I do is unthread the plug, and then use a long enough needle-nose pliers to lift the plug out of the port. Then the same pliers are used to gently set the new plug back in, and then thread it back in with the socket.
This method has always been fast and efficient for me, but nevertheless I definitely like the looks of that tool posted by @TheMAN (what DIYer doesn't like tools)
Thanks for the heads-up on that, and I'll keep the tool you posted in mind if this becomes a problem when it's time to change them.
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- ‘16 CX-9 GT
Ty for the link. Ordered my 80k plugs a few days ago. Saved 50% compared to the Werner Mazda parts site. Greatly appreciated!
I did the spark plug change on our 2020 CX-9 at 39k. I don't use a special socket for plugs. To get the plug out of deep wells I use a magnetic pickup tool. I use the same magnet to install the plug, you can spin the magnet and it will thread the plug in. I did check the spark plug gap on the used plugs and a 0.030 wire gage wouldn't pass thru. I kept the old plugs for backup. It feels like it idles smoother.
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- South Carolina
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- 21 CX-9 13 CX-5
I have to ask, why wouldn't you want to use the correct tool for the job? A spark plug socket does more than just hold the plug, the main purpose is to protect the delicate porcelain from damage. And at $14 a pop for plugs, I say that's pretty necessary!
I have spark plug sockets but the rubber has come out and disappeared. I've also had instances where the plug would drop out of the spark plug socket and fall and get damaged. Other times the rubber would stay on the spark plug so I use another technique.
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- Canada
I had that issue - the problem is the spark plug socket itself. You want to use one with a spring loaded clamp that grips the plug, or a magnetic socket. The ones with rubber inserts are prone to the issues you mentioned.
I bought my socket for like $7 on Amazon, but there are also better quality ones out there.
I bought my socket for like $7 on Amazon, but there are also better quality ones out there.
Just a word of warning to those who are changing their own spark plugs. Do NOT use anti-seize on your plugs when installing NGKs. They are designed not to require it, and in fact warn about using it. From their web site:
"NGK spark plugs feature trivalent plating. This silver or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without lubrication or anti-seize.
Anti-seize can act as a lubricant, altering torque values up to 20 percent, increasing the risk of spark plug thread breakage and/or metal shell stretch. Thread breakage can sometimes involve removing the cylinder head for repair. Metal shell stretch changes the heat rating of the spark plug and can result in serious engine damage caused by pre-ignition. Do not use anti-seize or lubricant on NGK spark plugs. It is completely unnecessary and can be detrimental."
"NGK spark plugs feature trivalent plating. This silver or chrome-colored finish on the threads is designed to provide corrosion resistance against moisture and chemicals. The coating also acts as a release agent during spark plug removal. NGK spark plugs are installed at the factory dry, without lubrication or anti-seize.
Anti-seize can act as a lubricant, altering torque values up to 20 percent, increasing the risk of spark plug thread breakage and/or metal shell stretch. Thread breakage can sometimes involve removing the cylinder head for repair. Metal shell stretch changes the heat rating of the spark plug and can result in serious engine damage caused by pre-ignition. Do not use anti-seize or lubricant on NGK spark plugs. It is completely unnecessary and can be detrimental."
Mine looked just like yours, but at 70k miles.
So is the general consensus that 40K miles is premature for most driving conditions?
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- Canada
I would say "probably". But the maintenance schedule calls for 40k mi so I would follow that interval at least until the car is out of warranty.
IMO, the plugs are readily available, and the job itself is very easy to do with a basic socket set and the right spark plug socket. Because of that I'll probably follow the 40k mi interval even when the engine is out of warranty.
Adding to the install tips...per NGK, the torque for this plug (12 mm threads into an aluminum block) is 10.8 to 14.5 lb-ft. (But for the "good is good enough" crowd, on every box, there's a tiny illustration showing the plug being hand-tightened 1/16th turn, and then wrench-tightened another 1/2 turn. As small as a Bazooka comic!)
Fawiek
Member
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- 2018 CX-9 GT
So I need a lil help plz!
2018 CX9 GT-- original owner with 127k kms.
I just sourced NGK Iridium plugs, the same mentioned here by the OP. Looked at a few videos and write ups and decided to take on the job.
The change itself is easy except for the problem that I ran into.
The plug on the far right is restricted by two rubber hoses that is sorta in the way but manageable. While replacing that last plug (always something ain't it!?) and securing the 8mm bolt, it stripped flush to the nut that's on the valve cover. I tried tapping into it and reversing but I may need to source another tap as the one I need for this size broke on me on another project and I couldn't use it.
I was able to McGiver a metal jacket onto a nearby 8mm bolt and extended it to hold, as in the pix. Has this happened to anyone? The bolt snapped under very light pressure using a small 4 inch socket. Only thing I can think of it may have been broken on the first plug change (at the dealer at 64k km interval) and they never bothered to say anything, though this is speculation on my part.
Also, I started each by hand and then snugged them all at the same time doing a little and moving onto the next, much like you'd do tires.
Anyways, it's holding in place but obv I don't want to leave it like this. I didn't take a picture of the broken bolt but it's the 8mm that holds the far right coil pack in place.
It's surprising how firmly it's being held in place but not looking to drive around like this, though it's working like a charm.
Thoughts on fixing this plz???
Also, that metal I put in place isn't touching any of the other piping that's nearby, just in case it causes some chemical reaction or cracks under vibration.
On another note, the car is much smoother, noticeable difference in acceleration.
2018 CX9 GT-- original owner with 127k kms.
I just sourced NGK Iridium plugs, the same mentioned here by the OP. Looked at a few videos and write ups and decided to take on the job.
The change itself is easy except for the problem that I ran into.
The plug on the far right is restricted by two rubber hoses that is sorta in the way but manageable. While replacing that last plug (always something ain't it!?) and securing the 8mm bolt, it stripped flush to the nut that's on the valve cover. I tried tapping into it and reversing but I may need to source another tap as the one I need for this size broke on me on another project and I couldn't use it.
I was able to McGiver a metal jacket onto a nearby 8mm bolt and extended it to hold, as in the pix. Has this happened to anyone? The bolt snapped under very light pressure using a small 4 inch socket. Only thing I can think of it may have been broken on the first plug change (at the dealer at 64k km interval) and they never bothered to say anything, though this is speculation on my part.
Also, I started each by hand and then snugged them all at the same time doing a little and moving onto the next, much like you'd do tires.
Anyways, it's holding in place but obv I don't want to leave it like this. I didn't take a picture of the broken bolt but it's the 8mm that holds the far right coil pack in place.
It's surprising how firmly it's being held in place but not looking to drive around like this, though it's working like a charm.
Thoughts on fixing this plz???
Also, that metal I put in place isn't touching any of the other piping that's nearby, just in case it causes some chemical reaction or cracks under vibration.
On another note, the car is much smoother, noticeable difference in acceleration.
Attachments
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- South Carolina
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- 21 CX-9 13 CX-5
That's an outstanding fix! It really is! Only thing I would say is maybe put a piece of rubber between your clamp and the coilpack.
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- Canada
I have to agree, great fix! I would echo theblooms suggestion to add a bit of heat-resistant rubber to really snug the jacket up to the coilpack. You'll be fine to drive like that until you can source the right tap.
Came across this page where this guy says he never uses a torque wrench....
Mazda CX-9 Spark Plugs Replacement Guide - Skyactiv-G Turbocharged 2.5L I4 Engine - 2016, 2017, 2018, 2019, 2020 & 2021 - Picture Illustrated Automotive Maintenance DIY Instructions
How to check or change the spark plugs in a second generation 2016, 2017, 2018, 2019, 2020 and 2021 Mazda CX-9 SUV equipped with the Skyactiv-G turbocharged 2.5 liter inline four cylinder engine including photo illustrated DIY steps and the compatible replacement part numbers.
www.paulstravelpictures.com
Fawiek
Member
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- 2018 CX-9 GT
It's a great write up, though I assume your intent was to imply sass than anything else.
To be clear, the bolt broke off before it was 1/4 way in, likely was broken but left for me to find as I had no torque using a 4 inch
.Meh.
The plastic housing that's holding the nut on the valve cover, anyone know if that is easily replaced rather than having to tap the existing one? It's likely to be cross thread anyways at this point.
Alternatively, I'm thinking tap with a smaller bolt to hold into place over the existing broken bolt.
It's simply to hold the coil pack snug.
I am pretty new at doing basic service jobs on my 2016 cx-9. I changed my spark plugs recently at 139k KM (I realize that this is way over the recommended 64k KM, but no dealer/garage had recommended it in the past and I only recently started reviewing my records to see where I was it). The old plugs still looked decent as far as I can tell by comparing to online photos (similar to those shown by Fawiek above). I had similar challenges with the re-insertion of coil packs 3 and 4 due to the tough angle. Took me quite a while to figure out that they weren't lining up straight on the top of the plug.
Ultimately, I was able to get the last pack in correctly, but the 8 mm bolt holding the coil pack in place made a awful plastic grinding noise going in and the pack in not tight like the other 3. It is fully in, but I can still move it a little. I don't think the car is misfiring, but I am not sure. When packs 3 and 4 were not lined up correctly, it was clearly misfiring. Now the engine sounds pretty normal to me, more or less like it did before. I just have this doubt because the pack wiggles a little.
Should I try to realign the bolt straight (maybe it went it at a poor angle... seems unlikely), or do I need to replace the coil pack (maybe I damaged the plastic on the pack?).
I welcome any advice... thanks!
Ultimately, I was able to get the last pack in correctly, but the 8 mm bolt holding the coil pack in place made a awful plastic grinding noise going in and the pack in not tight like the other 3. It is fully in, but I can still move it a little. I don't think the car is misfiring, but I am not sure. When packs 3 and 4 were not lined up correctly, it was clearly misfiring. Now the engine sounds pretty normal to me, more or less like it did before. I just have this doubt because the pack wiggles a little.
Should I try to realign the bolt straight (maybe it went it at a poor angle... seems unlikely), or do I need to replace the coil pack (maybe I damaged the plastic on the pack?).
I welcome any advice... thanks!
