I just replaced my 07 engine at 66k miles. Seems the spark plug loosened up and, over time, rattled around enough to chew out the threads in the aluminum head. Somewhere in this process, the "c" shaped ground electrode broke off and bounced around inside the cylinder. This in turn caused parts of the piston to break off, which by jamming between the piston and head caused the block to crack. What a mess! BTW, it was cylinder #5, which I understand is where this usually happens.

Moral of the story? Plugs may be good for ove 100K miles, but you might want to check them every 10 or 20k miles to be sure they are still properly torqued.

 

Its a known issue-at least around azine. Sorry to hear about your troubles, sounds like you experienced a worst case sanario.

 

damn thats crazy

 

That really sucks. No one listens but I've been saying since the beginning to replace the plugs more often. I use a regular copper plug and replace every 40-60k. That way I know they're tight, no worries about siezed plugs, and as a bonus I get to see what's going on in the combustsion chamber to hopefully catch any problems before they get too bad.

 

Is cylinder 1, 2, and 3 the ones closest to the firewall, and 4, 5, and 6 the ones near the radiator and fan?

 

Sorry to hear that. I just had my plugs replaced last month, but will be monitoring them every year or two.

 

Which plugs do you use?

 

yes
123
456

-I had a plug ALMOST back out on #2

 

I wonder if stiffer motor mounts would accelerate this issue.

 

It's one of two things. They weren't tightened well or those two cylinders are more prone to detonation which can loosen plugs, maybe an intake manifold air distribution issue.

I'm very curious to hear if this has ever happened to the same two cylinders after the OEM plugs were replaced.

 

Good question, Maybe some of them weren't tightened well from the factory? from what iv read, Honda says 13lbs (I think) and NGK says 18lbs. Anyways, iv made it a point to check mine once a month since I replaced the originals.

 

Acura says 13 with anti-seize, NGK says 18-21.6 (IIRC) but with no A-S.