Missing Spark Plug and Broken Coil?!?
 

My 2011 Manual Sport with 138,000 miles died on the freeway last week.

Cruising along at 70 mph, a strange, intermittent sound like a bird chirping started under the hood. Then, within a minute or so of that sound beginning, the motor died and I coasted off an exit ramp.

I can start the motor and it runs very weakly for a few seconds before dying and there is the loud compression leak sound.

Tow truck driver said it sounded like a spark plug blew out. Well I found a spark plug missing (#3) and the coil broken off where it bolts down. The bolt is still in place.

Did the piston rod break and slam the spark plug out or did the spark plug just come loose and the compression blow it out, breaking the coil?

What was the "chirping sound"? A bearing going bad before the piston rod broke or compression leaking around the loose spark plug before it came out completely?

UPDATE:

I put in a new spark plug. Only threaded in about 4 or 5 turns, but it's tight. I jammed the damaged coil onto it.

It fired right up and seems to be running perfectly fine.

Took it for a quick drive. Seems OK.

At about 30K miles, during the winter, my CEL was coming on intermittently (it also set off the VSA system alarm). Code said misfire in #2. Took it to the dealer and they changed the coil. Luckily I asked for the old coil (I really don't know if I got mine back but I got one and it smelled like gasoline).

3 days later the CEL was back on with codes misfire in #2 & #3. Dealer said it had to be the other coil. I said nah, something is fishy if a coil pack that sits outside of the engine smells like the inside of the engine.

I worked my way in from the passenger side left-handed taking of #1 coil and then plug, repeat. The spark plugs were loose on #2 & #3. #1 & #4 factory tight.

I bought the car new, it was never at the dealer after the first oil change, so why would the plugs just come loose? I'm still using the original coils and now have a spare.

To properly torque the spark plugs, you have to take off the windshield wipers. Then you have have take the rest of the car's ventilation airbox off to exposed the back of the engine. You can tighten the plugs without doing all of that work but you can't torque.

There are some old threads about plugs not being tight from factory.

What torque setting did you use Spike? I'm thinking of going with 18 LB/FT.

What threw me off when it first started happening, both the CEL and VSA lights were coming on (2011 first yr of VSA). But I found out that one begets the other: CEL will cancel proper operation of the VSA and that light comes on too telling you that it is disabled.

Even after proper torque of 13 lbf-ft (my big book covers 2009-2011) #3 came loose again. Right or wrong, I used blue thread-locker (Permatex paste in twist tube) and I haven't had a problem since.

So, if I properly torqued all of the plugs (without thread-locker) and one came loose from the same cylinder of one that worked loose "from the factory", and knowing that all spark plugs threads are equal, I have to assume that Honda's thread cutting process was flawed. For me, the blue thread-locker overcame the flaw for 3 yrs so far.

Blue is probably a good choice; hadn't thought of that. Temperature rating is good. Hopefully the threadlocker doesn't crumble when plugs are removed, else debris will fall into the cylinder. Even so, it's sure better than the plug coming loose.

I have some red for special occasions but like the taste of blue better. Sort of a sweet flavour.

I wouldn't worry if some dropped into the cylinder when removing a plug. It gets sort of chalky and should blow out upon startup.

My point is that at least for 3 yrs, the plugs didn't come loose again.

How common do you think this problem is? I'm starting to get nervous about going to pick up a '09 soon with 98k. Is this something I could easily check in a parking lot before bringing it home?

I wouldn't call it a deal breaker since some blue threadlocker fixed mine. Also, I haven't read many posts about the problem on-line and Honda didn't issue a recall (only assuming since I didn't get one on spark plugs but did get one for the airbag). So, a small number of occurrences. If the CEL (check engine light) doesn't come on in the first 50-60 miles, you should be OK. Just post, we cam help.

And I read of people using engine oil or anti-sieze compound on spark plugs. This blue medium duty threadlocker stuff sounds like a good sealant idea in my books. :thumbups: 2cents.

What torque settings are y'all using for your 'GE' coil packs? I'm thinking about 72 IN/LB (6 FT/LB) maybe, or is that too much? Thank you.

The holes in the coil packs are metal lined on the stock ones, I believe so they are not real torque picky. Plugs popping out of Japanes OHC engines,, old stuff the Miatas did it, the MR2's did it, pretty much all deep set plug engines.. Not sure why.. But I clean the threads of the hole with a plastic rifle brush then use just a tiny dab of oil on the first thread, never had issues... (VW bugs did this in the 60's.. :) )

Checking my spark plug torque this weekend, first time into it all. Getting the upper and lower cowls off was easy, no sweat at all.

Took me a while to figure out the trick to getting the electrical connectors off the coil packs. (Pinch in at the rear of the connector on the longest flat side of the connector, then push forward and pull back). It's TOUGH and it gets progressively more difficult as you progress toward the driver's side (North American) because there's not much room for your hands.

I'll remove the coil packs tomorrow and check plug tightness.

I made the same mistake the first time before taking the cowling off. You should be able to "pinch" the end of the blue tab on the wire end and the "jaws" will open and release the connector from the coil pack.

I also found that wearing a mechanic's glove helped too. Pinching the connector, while pushing and pulling on it HURTS after a while. :-)

Well, all of the mechanical work went fine and my spark plugs were tight with no looseness whatsoever.

Problems came when I tried to install the upper (plastic) cowl with all of those @%^@&(*! plastic clips. I'd press it in place and some would engage, but not others. Then I'd have to pull the cowl away to see what was up, breaking more clips. Then I'd try again and another wouldn't engage, leading to more breakage.

I made the mistake of not looking carefully at each clip when I began the installation. Some clips looked like they were okay, but one leg was cracked on some and I didn't notice. On Monday I'll go to the Honda dealer and replace all of the bad clips at once and try it again. At $3.24 Ea (!) I hope it works.

It's my daughter's car and we both want it back on the road.

https://cimg3.ibsrv.net/gimg/www.fit...1d690dd0a6.jpg

As I worked to remove the lower cowl, I had to pause and think it through. Here it is removed with the wiper mechanism intact and untouched. As I think it's been noted here, you do not need to remove the wiper mechanism from the cowl.

I left the wiper "transmission" in the car and just took the lower tray out after removing the plastic top.

https://cimg1.ibsrv.net/gimg/www.fit...46532e49cb.jpg

https://cimg3.ibsrv.net/gimg/www.fit...4bc0e31aa5.jpg

https://cimg5.ibsrv.net/gimg/www.fit...3299c9c6ec.jpg

You can see that you just pinch the signal wire end of the blue latch and the jaws on the coil packet end will release. I also marked "Original #1, etc" just to prove to myself that there was never a problem with any of the original coil packets, just #2 & #3 plugs were loose.

Good photos. In the above photo, I'm guessing that the circular component to the left is the Oxygen Sensor?