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

[sm1ke]

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.

 

[mzdcxuser]

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!

 

[sm1ke]

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.

 

[mzdcxuser]

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).

 

[sm1ke]

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.

 

[PTguy]

...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.

 

[mzdcxuser]

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.

 

[Fawiek]

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 ..