I've had my '00 Black S2000 since new, it's bone stock (aside from a leather center console cover and a glass window robbins top). It has 95K miles on it. It started making a tapping sound, intermittent and only at certain throttle settings but no other symptoms about four months ago. I've had the stethoscope on it and tried various things to figure out what was going on, but couldn't find any issues, I thought maybe something was going on with a valve. Finally it suddenly started running very rough, rattling, misfiring on all cylinders and making backfiring sounds, the check engine light came on flashing. I shut it off and coasted into a gas station. This happened at a light throttle setting cruising down a boulevard at about 30 mph. I had it towed home. Started to pull the spark plugs to do a compression check first and see if a mechanical problem was going on thinking I'd find a valve problem or piston problem, but discovered the #3 spark plug had come loose, and melted the coil pack. It also ate all the threads in the spark plug hole entirely. I can drop the plug all the way down to where it would be if tight without even turning it, it's a smooth hole now with no threads at all. The spark plug was intact, loose and ready to give up, but no parts of it have fallen into the cylinder. All 3 other cylinders are just fine. I had a loose spark plug happen when it was still under warranty like 12 years ago and the dealer fixed it back then, the CEL came on right away and the threads weren't damaged. Don't know if it was the same cylinder or not, the records are buried in storage.

I'm thinking about using a 'TimeSert' kit on it to replace the threads.

I was looking at these kits: Timeserts

Has anyone else experienced a loose spark plug to this level? I hate to have to be cutting metal in the spark plug hole, but don't see any other option short of pulling the head!

 

Timeserts or Heli-coils would be about your only choice.

Good luck with the fix!
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Don't use a heli-coil, please. For something like the spark plug that is routinely removed and reinstalled, a heli-coil won't hold up over time. If you're local to me (Tennessee), I have the appropriate time-sert kit and inserts to do the repair, along with the expertise and experience required for doing a head-on repair. Doesn't take more than an hour or so, and in the end you're driving off as if nothing happened.

 

Amen.

 

Jordanksartell, Thanks, for the Time-sert tip. Do you use Loc-tite or some such adhesive when inserting these? Let it dry. Then, replace spark plug?


Thanks!

 

It's good to hear that timeserts are a solid fix. I usually do all of my own work, but this one has me a bit spooked because it's a one shot deal, if I screw it up, I'll have to pull the head to make it right. I'm in Southern California and don't know anyone that I'd be comfortable with doing the work on this one. If you know anyone qualified and experienced with Timeserts in the San Diego area, let me know.

 

Time sert is self locking, that's the time in time-sert(self clocking). Once you insert it it's not going to move. It's done much like a helicoil, you tap the hole and place the insert, and instead of being a coil winding it's a solid insert.

 

Check your compression first if you can with a narrow rubber pointed adapter shoved into the hole.
If the compression is off, you'll have to pull the head anyway and the insert is a lot easier to install clean with the head off...

 

Top of Under the Hood Forum/Blue Stickies/FAQ,DIY,Maintenance/Engine Stuff/Spark Plug Thread Repair (4th post down)

Make sure you flush with shaving cream as chris_barry recommends later in the thread!

Thank me later

Utah

P.S. Scary the things my peanut sized brain retains; like where things are here....

 

Everybody has a talent.