Knocking noise changed all spark plugs?

JTAYLOR0826

MEMBER
2021 HONDA PILOT
6 CYL
4WD
AUTOMATIC
15,000 MILES

Changed all spark plugs and now there is a knocking noise with acceleration that was not there prior to the spark plug change. The ignition coil connectors do not "click" into place but there does not seem to be a difference in the noise when I push and hold them in place. No check engine light is on. What could the knock be?

Wednesday, February 4th, 2026 AT 1:10 PM

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
54,860 POSTS

I would remove the spark plug to check for damage and to double check the correct spark plug were installed. Here are the correct spark plug which should be installed,

NGK DILKAR7H11GS (OEM)

Also, it can sound like knocking if the spark plug is not all the way seated or cross threaded, if you upload a short video of the noise I can tell for sure. Also, sometimes debris can drop into the spark plug hole while changing is being done. I should be able to tell from the video. Ken

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Thursday, February 5th, 2026 AT 10:07 AM

JTAYLOR0826

MEMBER
2 POSTS

This is the sound it is making. It does not make it when idling, only when accelerating and it gets to about 2000 rpm and stops as soon as we take foot off throttle. Could it possible be weak ignition coils? We replaced 2 of the 6 ignition coils. Also no check engine light is coming on. We removed the spark plug on cylinder and this is what it looks like, which is different than all the others. It was just replaced less than a week ago.

Image & Video (Click to make bigger)

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Thursday, February 5th, 2026 AT 10:14 AM

KEN L

MASTER CERTIFIED MECHANIC
54,860 POSTS

Yep, the video is in the new apple phone format so I cant view it because this site has not been updated yet. Sorry, you can change the setting on the phone to make it a different format so I can hear the engine noise. I don't want to steer you in the wrong direction. The spark plugs look correct. Even though the check engine light is not on it can still have a code, here is a video to show you how to run them to see. This can tell us which cylinder is having the issue.

https://www.youtube.com/watch?v=LBCpCWEFnTg&pp=0gcJCZEKAYcqIYzv

Please go over this guide and get back to us.

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Friday, February 6th, 2026 AT 7:38 AM