Cylinder or piston damage is possible if anything foreign got in there. Also if a piece of spark plug or head threads go bouncing around, that could have caused it. I strongly suspect it was associated with blowing the plug out. Remember that for every compression and exhaust stroke that occurs blowing things out of the hole, there are two other downward strokes that could suck things in. Without the actual pieces in hand it is difficult to guess what caused the damage. It also could be something left in the cylinder when the head was replaced. You really have to pull it apart to see what damage there is and maybe you will see what caused the damage.

On the blown out plug was there some parts of the plug like pieces of the electrode or insulator missing?

 

Mahout gives good advice and is not losing his mind. Unlike some of the trolls on here.

 

Yes, the entire plug--it was completely gone, no pieces, nothing. Just a hole, like the one in my wallet now.

I was thinking it could have sucked something in, but visual inspection showed no damage to the cylinder from something banging around in there. I guess anything is possible.

 

Welcome to the forums.

 

Thanks for the welcome.

 

FYI, the EXACT same thing than Tjones happened on my FIT. I'm at 123000 miles, changed the plugs myself at 100000; didn't use anti-seize (please don't judge...)

I was having unexplained exhaust smell coming in from the vents when the car stopped, brought the car to various places and no one could figure it out. The engine was running perfectly fine other than the exhaust smell issue. Months later, BOOM, spark plug #3 gets blown out. The local garage installed a helicoil in the head and put everything back in place. The engine runs fine now, the exhaust smell is gone, but just like Tjones, the engine is making a weird ticking sound. It gets significantly louder when the engine is under load; as soon as I let go of the gas, it can only quietly be heard.

TJones, did you get to the bottom of your problem ? Does anyone know what this new ticking can be, and if new issues can arrise from this condition ?

Thanks,
Glenn.

 

I recommend a valve clearance check and a compression test afterwards. Ticking is first on our list of sounds that involve the valves. More often than not a loose gap that lets the valve seat soundly. Not enough spring pressure.
Carefdully examine the rocker arm structure as well just in case.
cheers good luck.

 

Thanks for taking the time to answer, I appreciate it

I just got a valve adjustment less than 1000 miles ago at the dealer and it was purring perfectly right before the blowout. Could the blowout have messed up the adjustment, or done something worse ??

 

Glenn24,
My ticking was diagnosed as piston slap from something damaging the cylinder, presumably debris being sucked in from the plug explosion. It was also only when the engine was under load. After the plug ejected, Honda replaced the entire head rather than inserting a helicoil, so it was not a valve issue. They did this because I was in negotiations about how much they might help out on the repair. Since Honda was involved, they would only go with an OEM solution. I doubt they would be willing to help you out since you did the plug replacement yourself. To their credit, Honda American Corp. did pay a major part of the repair cost on my engine, which indicates to me they were willing to take some responsibility for the improperly torqued plugs. The whole experience did earn the car a new nickname, too: the Sake Bomb.

 

"My ticking was diagnosed as piston slap"


What's the status of this piston slap noise?


Thanks.

 

It's gone. They replaced the short block.

 

While I am not an expert, I do not think that debris from an exploding spark plug would cause piston slap.

Piston slap is the result of poor tolerances between the piston and the cylinder, usually due to 1) excessive wear or 2) design flaw. I do not think that the sudden trauma of a spark plug explosion would result in piston slap, but perhaps others who have greater knowledge can chime in on this.

 

Thanks for the info guys, I appreciate it very much.

looks like I'll be reading up on piston slap today !

 

^^I mention piston slap because it has been suggested as a cause of a noise associated with some of our engines. This is an issue completely unrelated to exploding spark plugs. However, we have no definitive answer to date.

 

So the ticking sound, diagnosed as piston slap, was after spark plug ejection and cylinder head replacement. The theory was that debris from the exploded plug caused wear on the cylinder wall or damaged the piston. Dismantling the whole block to find the exact cause was going to cost as much in labor as replacing the whole thing. Since Honda was offering to pay 2/3rds of the repair, I went along with it. I basically got all the replacement parts for free and paid for the labor. I don't know if I was taken for a ride, but the engine has been performing MUCH better since the whole thing went down, and I'm getting better mpg than before. That said, the tech went to the trouble of removing the three old plugs from the damaged head and putting them into the new engine

My original intent for this post was to get some help determining if the dealer was being honest on my repair, but somehow we got off into the weeds with lubricating or not lubricating plugs, torques, etc. and I just gave up.

 

Sitting in dealership following plug and coil blow out. Both coil shaft and plug are roadside. Limped to dealership on three cylinders. Awaiting more info. Similar to other posts detailing this problem.
Dennisff

QUOTE=Carbuff2;1163549]On another forum I belong to (Dodge minivans ) owners report finding loose sparkplugs after seeing misfires. This, on factory-installed plugs.

Those cars do not have coil-over-plug though. Why wouldn't the Acura (V6), Accord or CR-V (both K24 engines) owners report loose plug problems? (<--- all C-O-P designs)


For that matter, why wouldn't a bolted-on coil pack prevent a plug from coming loose?[/QUOTE]

 

Changing/increasing under load indicates piston slap...not valve clearance. You may have a scar on the bore. Or you're running poor grade of gas.

 

Today I am advised by my Honda Dealer that my 2009 Honda Fit with 90,000 miles blew out one of the plugs and took the ignition coil with it. They are going to put in a Helicoil since the threads are damaged but not beyond repair.

It is interesting to note that in January of 2015 my wife's '12 Fit with 30,000 miles did the same thing but didn't have any head damage.

 

Just to be clear: The problem is that the spark plugs were never torqued down properly from the factory, and they eventually work themselves loose? Or the plugs are working themselves loose regardless of whether they've been torqued properly?

Thanks.

 

I'll ask this afternoon when I'm suppose to pick up the car. At the moment I don't know.