2016~2023 CX-9 41K spark plug change, found NGK plugs in the wild

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!

So for the last bolt, you're unable to tighten the bolt any further, and the coil pack feels a bit more loose than the others? It's possible that you crossthreaded the bolt that snugs the coil pack. You could probably remove the bolt and try using a thread chaser to repair the threads, but then you'd risk getting metal particles in places you don't want them.

This is just a temporary solution, but I would find a plastic washer that would fit between the bolt and the coil pack, something just thick enough to shim the bolt up against the coil pack. Cut them on one side so that you can slide one or more under the bolt without having to remove the bolt.
 
Thanks for that. It's a bit odd, because the bolt looks all the way down. There is no gap or exposed bolt anymore. (but maybe not 100% straight? see photo). There is no vertical wiggle on the pack, just a little rotational and horizontal wiggle that is noticeable.

Can I safely disconnect that hose sitting over top of the pack for closer inspection?

Thanks again!
 

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Thanks for that. It's a bit odd, because the bolt looks all the way down. There is no gap or exposed bolt anymore. (but maybe not 100% straight? see photo). There is no vertical wiggle on the pack, just a little rotational and horizontal wiggle that is noticeable.

Can I safely disconnect that hose sitting over top of the pack for closer inspection?

Thanks again!

To me, it looks like there's maybe a millimeter of space between the bolt head and the coil pack, which is probably enough to let it wiggle slightly. I checked my coil packs they don't move at all.

I'm not sure if the hose can, or should, be disconnected. It looks wedged on the fittings pretty good, and if you were to remove it, you'd need to make sure the yellow mark lines up where it did before. If you have some paper near by, you could try folding it up and wedging it between the coil pack and the bolt. That would also give you an idea of how thick the plastic washer(s) need to be to get everything tight.
 
I will try that, thx very much! Really appreciate your help.

One last question: is there any way to that my underlying spark plugs are working optimally, other than listening for misfiring? I don't hear anything obviously concerning. I've driven about 105 km since install and I'm getting about 12.3 L/100 km, which probably about the same as before (was at 11.8 before over a lot of highway driving).
 
I will try that, thx very much! Really appreciate your help.

One last question: is there any way to that my underlying spark plugs are working optimally, other than listening for misfiring? I don't hear anything obviously concerning. I've driven about 105 km since install and I'm getting about 12.3 L/100 km, which probably about the same as before (was at 11.8 before over a lot of highway driving).

If you don't have any codes and the car idles and accelerates as smoothly as it did before, you should be fine. Sounds like you had no issues with the plug installation at all, only that one coil pack.
 
...is there any way to that my underlying spark plugs are working optimally....
Working vs. working optimally. That can be a difference. At 40k miles new plugs gave the car a bit more giddy-up. The old plugs were working smoothly. The new plugs just worked better...more optimally.
 
Working vs. working optimally. That can be a difference. At 40k miles new plugs gave the car a bit more giddy-up. The old plugs were working smoothly. The new plugs just worked better...more optimally.
Fair enough. So far, I am not noticing a big difference. Gas mileage is actually improved a little now, which is nice.
 
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!
Really easy to cross thread as the angle is a bit tough, even using your fingers to start. Not sure how others managed this but if it doesn't go in right away, walk away from it for a half hour and regroup -- worth it to be patient with the thing.

No issues on my McGiver'd 4th plug housing so far ..
 
So what should the gap be on these, looks like they are pre-gapped at 0.030", is that correct for the 2.5L Turbo?
has anyone check the gap on the old plugs to see if there is any wear other than a visual look?
40K on iridium does seem maybe a little premature, but with only 4 the cost isnt too bad, especially if you source them from Rock Auto.
 
They are about 167 at my local stealership. I was like 😮. Now I know when I approach the 39k mark I will not purchase them from this dealership.
 
The gap on modern high tech spark plugs is set at the factory and not intended to be set in the field. On olden days with copper spark plugs, I know, we had to set the gap when we installed them and when we cleaned them.
 
Yes, modern plugs come pre gapoed, but no one plug can be gapped right for every application.
Plenty of times ive had to regap iridium, plat, plugs cause they didn't match my factory spec gap.
So,my question still stands, anyone know the gap for the 2.5 turbo?
And by the way, ive bought many NGK, Denso plugs that despite being factory gapped were not all the same, and some even had some mis alignment were the top iridium tip or U groove on Densos did not perfectly align with the main electrode tip, resulting in sub optimal spark.
I have a plug tester and visuslly inspect gap, alignment and spark. My tester has shown improved spark when aligned spot on.
Some cars aren't the easiest to change plugs on, this level of checks and detail can save a lot of time.
 
I just measured mine and right, they are at 0.030" +/- 0.001.

Still would like to know what Mazda says the gap SHOULD be, just because they are pre gapped at 0.030 doesnt mean its correct for our engine, unless this is the only engine using this plug.
It very well could be the correct gap, would just like to confirm it from Mazda.
Maybe I just havent looked hard enough yet, in the owners manual manybe?

I guess what Ill do is measure the old plugs when I get them out, at 51,000 miles, and having an iridium tip and platinum ground, they shouldnt be all that worn, so then I can corroborate the 0.030" spec/pre-gap.
 
Ok did my plugs. Removed the original OE Mazda olugs, the electrodes looked really good, with no wear, they still measured at 0,030in, so that confirms the NGK laser iridium replacements are gapped correctly at 0.030in. See pucs.
The only thing I noticed was the heat marks right at the base of the white ceramic next to the metal hex head. Not sure what this means.
I noticed no difference in performance after the change, but with no real wear im not surprised, nore should we given these are iridium. I think the Mazda 40k requirement might be more for heat related degredation, as seen on the insulator.
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I also scoped the cylinders, and they all looked pretty clean. 2 and 3 where near TDC so you cant see much, but here is cyl 1, 2, 3, 4 in that order A little carbon near the edges , but pretty clean for 51k, not oily in anyway, bone dry. I did run techron in the past a couple times, and used CRC GDI intake valve cleaner just prior to this plug change
This CRC cleaning I feel did improve performance. It wasnt running bad at all, but I do notice more torque, which is easy to quantify as I get more tire squeal from a start then the drive right before. Worth using the CRC even if these engines do better with valve deposits than others, they are still GDI engines!

Not sure what the rusty looking rings are near the centers on 2 and 3.
And my scope can't look back at the valves nor the cylinder walls, would be curious to see those. I might have to upgrade to a better one.
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