Near Disaster: Check Your Spark Plugs
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From: Plano
Near Disaster: Check Your Spark Plugs
If your car has been having idling problems, or has the "Check Engine" light come on for mysterious reasons, read on. This post is a bit lengthy, but the problem was serious enough, unlikely enough, and potentially disasterous, that it merits a complete description and warning. I strongly advise you to check that your spark plugs are tightened correctly. I would also like any insight the mechanical experts on this site may offer.
My S2k was purchased in October 1999. I drive it energetically, and I have been in a half-dozen driver's education track days. But it's not modded, and I have it serviced religiously (i.e. more frequent fluid changes, and 15k and 30k services were done early). It now has just over 30k miles on it.
About 10k miles ago or so, it started idling weirdly and intermittently dying while at idle. My dealer replaced the manifold air pressure sensor and the idle air control valve, but nothing seemed to fix the problem. Their computer showed either no problem, or that I overfilled the gas tank (though I filled exactly the same way as when the light did not appear). Every few weeks, it would go through a spell of dying, and then it would disappear except for the rough idle. I had a standing arrangement with the dealer to bring the car in immediately when the problem occurred, so their diagnostics could perhaps catch the error, but never had the chance.
Last week, after a thorough service and checkup, I drove it from Texas to Laguna Seca for that great S2KCA event. It ran fine, although the idle was rough as usual. On the road and on the track, no other noticeable problems. It did get slightly less highway gas mileage than my previous, identical trip two years before (25mpg vs 28mpg).
Two days after Laguna Seca event, we started our return trip to Texas, planning to reach Palm Springs that night. Around about Bakersfield (say 300 miles away, at about 3:00pm), the "Check Engine" light came on, though the car was running fine. Using the cell, I called both my customary Dallas dealer and the local Bakersfield dealer. Both service advisors said that the "Check Engine" light indicated an emissions problem and that if it showed steady (i.e. not blinking) and the car was running fine, we could continue without worry and look at it in Dallas. So we continued towards Palm Springs but decided to call it a day at about 6:00pm in Yucca Valley.
The next morning, the car started fine, but within a mile or so it started missing badly, making a loud clicking sound and the "Check Engine" light started blinking. I limped the car a half-block to a gas station and called my Texas dealer. He advised me to have it towed into a Honda dealer immediately. I called the nearest (Honda of the Desert in Cathedral City) and they recommended a towing company. We flat-bedded the car into Honda of the Desert (HOTD) and by 1:00pm that day they had diagnosed the problem.
The spark plug in the number one cylinder had inexplicably unscrewed itself, and the resulting combustion blow-by burned the plug wire and the surrounding metal sleeve, which in turn finally caused the coil for that cylinder to die. I saw the ruined part myself, and took a photo of it which I will post when we get home.
I am not mechanically inclined, and do not work on the car; no-one works on it but my local dealer. To it's recollection, the dealer has never unscrewed, replaced or otherwise dealt with the spark plugs.
The spark plug itself, though covered with soot, is physically in perfect shape. That is, the threads are fine (not stripped or cross-threaded). It truly appears to have worked it's way out of the cylinder over time. The point is burnt out, and the body of the plug all the way back is covered in soot. The metal sleeve that protects the plug wire as it passes through the valve cover is also charred, and the bottom half inch or so is unevenly burned or melted off. And the coil was non-functional.
After a bit of Fedex rigamarole, HOTD had a new coil assemply overnighted from a Honda parts warehouse in French Camp, California. They removed the valve cover, inspected it and the valve train and found no damage. They inspected the cylinder and found no damage. They adjusted the valves and put in a new spark plug along with the new coil assembly. The total charge was about $400.00 ($300.00 plus parts) and Honda covered both it and the $180.00 tow under warranty.
I have driven the car for about twenty miles since the repair and it appears to be fine throughout the rev range. In fact, the rough idle problem is gone and for the first time in a long while the car idles smoothly as it did when new.
Tomorrow we will head down I-10 east for Texas, and we'll see how it goes.
Once again, I urge you to check your spark plugs for proper torquing, and am asking the technical experts on this board for any insight into what occurred. I can only guess that either at the factory or sometime thereafter someone did not torque the spark plug down properly.
How the car could run fine at all RPMs (except idle) yet have a spark plug gradually backing out, and show no indication in performance or diagnostics, I have no idea. It's very fortunate the problem did not occur somewhere remote on the interstate when I was driving from Texas with my 76-year-old dad, or cause major problems with the engine.
Paul
My S2k was purchased in October 1999. I drive it energetically, and I have been in a half-dozen driver's education track days. But it's not modded, and I have it serviced religiously (i.e. more frequent fluid changes, and 15k and 30k services were done early). It now has just over 30k miles on it.
About 10k miles ago or so, it started idling weirdly and intermittently dying while at idle. My dealer replaced the manifold air pressure sensor and the idle air control valve, but nothing seemed to fix the problem. Their computer showed either no problem, or that I overfilled the gas tank (though I filled exactly the same way as when the light did not appear). Every few weeks, it would go through a spell of dying, and then it would disappear except for the rough idle. I had a standing arrangement with the dealer to bring the car in immediately when the problem occurred, so their diagnostics could perhaps catch the error, but never had the chance.
Last week, after a thorough service and checkup, I drove it from Texas to Laguna Seca for that great S2KCA event. It ran fine, although the idle was rough as usual. On the road and on the track, no other noticeable problems. It did get slightly less highway gas mileage than my previous, identical trip two years before (25mpg vs 28mpg).
Two days after Laguna Seca event, we started our return trip to Texas, planning to reach Palm Springs that night. Around about Bakersfield (say 300 miles away, at about 3:00pm), the "Check Engine" light came on, though the car was running fine. Using the cell, I called both my customary Dallas dealer and the local Bakersfield dealer. Both service advisors said that the "Check Engine" light indicated an emissions problem and that if it showed steady (i.e. not blinking) and the car was running fine, we could continue without worry and look at it in Dallas. So we continued towards Palm Springs but decided to call it a day at about 6:00pm in Yucca Valley.
The next morning, the car started fine, but within a mile or so it started missing badly, making a loud clicking sound and the "Check Engine" light started blinking. I limped the car a half-block to a gas station and called my Texas dealer. He advised me to have it towed into a Honda dealer immediately. I called the nearest (Honda of the Desert in Cathedral City) and they recommended a towing company. We flat-bedded the car into Honda of the Desert (HOTD) and by 1:00pm that day they had diagnosed the problem.
The spark plug in the number one cylinder had inexplicably unscrewed itself, and the resulting combustion blow-by burned the plug wire and the surrounding metal sleeve, which in turn finally caused the coil for that cylinder to die. I saw the ruined part myself, and took a photo of it which I will post when we get home.
I am not mechanically inclined, and do not work on the car; no-one works on it but my local dealer. To it's recollection, the dealer has never unscrewed, replaced or otherwise dealt with the spark plugs.
The spark plug itself, though covered with soot, is physically in perfect shape. That is, the threads are fine (not stripped or cross-threaded). It truly appears to have worked it's way out of the cylinder over time. The point is burnt out, and the body of the plug all the way back is covered in soot. The metal sleeve that protects the plug wire as it passes through the valve cover is also charred, and the bottom half inch or so is unevenly burned or melted off. And the coil was non-functional.
After a bit of Fedex rigamarole, HOTD had a new coil assemply overnighted from a Honda parts warehouse in French Camp, California. They removed the valve cover, inspected it and the valve train and found no damage. They inspected the cylinder and found no damage. They adjusted the valves and put in a new spark plug along with the new coil assembly. The total charge was about $400.00 ($300.00 plus parts) and Honda covered both it and the $180.00 tow under warranty.
I have driven the car for about twenty miles since the repair and it appears to be fine throughout the rev range. In fact, the rough idle problem is gone and for the first time in a long while the car idles smoothly as it did when new.
Tomorrow we will head down I-10 east for Texas, and we'll see how it goes.
Once again, I urge you to check your spark plugs for proper torquing, and am asking the technical experts on this board for any insight into what occurred. I can only guess that either at the factory or sometime thereafter someone did not torque the spark plug down properly.
How the car could run fine at all RPMs (except idle) yet have a spark plug gradually backing out, and show no indication in performance or diagnostics, I have no idea. It's very fortunate the problem did not occur somewhere remote on the interstate when I was driving from Texas with my 76-year-old dad, or cause major problems with the engine.
Paul
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Joined: Oct 2000
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From: Davie, FL
Paul - This is a very important report, and I'm happy that your outcome wasn't as dire as what happened to Greg Stevens. His car died and needed an engine replacement probably due to a spark plug failure. His experience prompted me to check my plugs, and indeed one of them was very loose. Many others have reported loose plugs as well.
To all of you out there that doubt this - read the following link and then go out and check your plug torque. https://www.s2ki.com/forums/showthread.php?...loose+sparkplug
To all of you out there that doubt this - read the following link and then go out and check your plug torque. https://www.s2ki.com/forums/showthread.php?...loose+sparkplug
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From: Laurel
One in five cars in this poll: https://www.s2ki.com/forums/showthread.php?...poll+sparkplugs
I believe this is due to a wrong factory spec. I don't remember the details of the difference between the Honda and NGK recommendatoins for plug torque but it's in the thread.
I believe this is due to a wrong factory spec. I don't remember the details of the difference between the Honda and NGK recommendatoins for plug torque but it's in the thread.
Joined: Jan 2001
Posts: 3,290
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From: Atlanta
I experienced this problem with my '87 Civic SI. It blew a plug on three different occasions. It's just a matter of having the proper torque on the plug which may need to be checked every so often. Remember, the plug threads are steel but the block is aluminum so the expand and contract at different rates. This might explain why the plug will loosen over time.
Joined: Jan 2001
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From: Mish-she-gan
As often as this has happened, I keep wondering why Honda has not issued a TSB on this to either increase the torque setting recommendation, or if that's not the answer - to list checking the plugs on a regualar schedule with shorter intervals.
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From: On the lakefront...
Wow Paul, I'm glad that you caught that before what happened to me happened to you. The main thing that upsets me about having lost that engine was that it was such a strong one. It dyno'd at 210 at the wheels... 
(OK, it has a few bolt on's, but other owners who rode in my car were always saying things like, "Wow, my car is nothing like this!")
Honda replaced the long block and only time will tell if this engine will be as strong as that one. I only have about 1500 miles on this one now...
I know of two other failures along the same lines as mine. It hasn't been conclusively proven what happened exactly, but the consensus is that the spark plug coming out of the head had SOMETHING to do with it.
This is a great reminder for everyone who missed my ordeal to go out and check the plugs to make sure they are in spec...it might be good to revive that thread just to drive the point home.
And it was a pleasure meeting you, your dad and mom. What a cool story you have now!
And everyone else, check your spark plugs!!
(OK, it has a few bolt on's, but other owners who rode in my car were always saying things like, "Wow, my car is nothing like this!")Honda replaced the long block and only time will tell if this engine will be as strong as that one. I only have about 1500 miles on this one now...
I know of two other failures along the same lines as mine. It hasn't been conclusively proven what happened exactly, but the consensus is that the spark plug coming out of the head had SOMETHING to do with it.
This is a great reminder for everyone who missed my ordeal to go out and check the plugs to make sure they are in spec...it might be good to revive that thread just to drive the point home.
And it was a pleasure meeting you, your dad and mom. What a cool story you have now!
And everyone else, check your spark plugs!!
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From: SoCal
Checking the plug torque every so often is a good idea, especially if new plugs have been installed. I surmise the torque specification is enough to crush the washer, but then only torque the plug in further by only a little more torque. My checking the torque later of fresh plugs tended to show that the plug could be turned in further to torque specification after the washer had time to really seat.