spark plug denting

I drive a 2003 Cavalier. Last year I added nitrous to it and have haad no problems at all. However, during the winter, i have encountered a problem. I take my nitrous out during winter and do not use it at all.

One day I was driving normally and got up past 3000 rpm when I had a sudden lag in power and a sound like one of my cylinders was not firing properly.

My check engine light lit up and and I released the gas and cruised to a stop. My car kept running, however, but it acted as if, like it sounded like, one of my cylinders were not firing.

I drove it home and checked all my plugs. The plug closest to the driver's side wheel was pushed in a bit with some indication on the very tip that it ahd been hit. I guessed at the time that the cylinder must have hit the tip of the plug, causing the gap to become virtually non existant.

I regapped the plug and had no other problems until a week later. I had gotten up past 3000 rpm in the meantime and experienced no probs. However, this time it happened again but this time the car actually died and stopped running, causing me to pull over immediately. After trying to start up quickly and failing, I let it sit for a minute and then was able to restart it. Once again, the same problem had occurred as I rechecked the plug. I went and bought a new plug, this one much shorter than the other one. I put it in and everything ran fine until a few days later when the problem occured again. Only this time I had lots of people in my car with suitcases in the trunk, and was not over 3000 rpm when it happaned. Once again I checked and the plug tip had been dented in obviously.

I am not exactly sure how my piston could be hitting my spark plug on that side only. Perhaps whatever the bottom of the piston is attached to is loose somehow (I assume from running nitrous). Is there an easy way to open up the block and fix this?

Has anyone else had this problem? The new spark plug has already gotten a bad carbon buildup also after being in for about a week. My check engine light is off now but I assume my o2 sensor may be bad. However, if I don't go above 3000 rpm I have no problem. I would imagine the problem will only get worse, though.
Any suggestions?

Nitrous huh, ever consider you detonated a piston, Now there is a burnt section sticking above the piston top or a piece broke off and is hitting the plug. Try and get a borescope and look down the plug hole into the cylinder or pull the head, you should not be driving the car this way. Also based on the tone of your questions, you will need professional help with this.

[maxwedge] said: Nitrous huh, ever consider you detonated a piston, Now there is a burnt section sticking above the piston top or a piece broke off and is hitting the plug. Try and get a borescope and look down the plug hole into the cylinder or pull the head, you should not be driving the car this way. Also based on the tone of your questions, you will need professional help with this.

ANSWER- If I had detonated a piston I would think the problem would occur all the time, not just above 3000 rpm. I am not sure what you mean by burnt section sticking above the piston top....do you mean part of the piston is chipped off or soemthing?

As far as driving the car that way, I don't think you are in any position to state this. It is my second car that I meant to have fun with and to learn how to tool around with. A cavalier is just a cavalier, nothing too big to worry about. I got the in order to beat the hell out of, and it has held its own.

Another thing I would like to point out is that the problem never occured while I was running nitrous. It has only occured this winter, several months after I had run nitrous. The ecotec motor has served me well in the past, and I expect it is a simple fix if the right tools are to be gotten.

are you trying to compress water. depending on the motor head gaskets are known to go bad.

Since this is peculiar to the one cylinder, my best guess is that you broke one of the top ring lands on the piston. The loose piece is bouncing around the combustion chamber and once in a while manages to get compressed.

Now you say that the plug tends to foul, you might have even broken a piston ring. I predict that once this motor is taken apart you'll find a broken up piston in the suspect cylinder, cylinder scoring and the rings will no longer be in one piece. The other cylinders may have latent damage which should show up in a visual inspection.

Bob

[maxwedge] said: Nitrous huh, ever consider you detonated a piston, Now there is a burnt section sticking above the piston top or a piece broke off and is hitting the plug. Try and get a borescope and look down the plug hole into the cylinder or pull the head, you should not be driving the car this way. Also based on the tone of your questions, you will need professional help with this.

ANSWER- If I had detonated a piston I would think the problem would occur all the time, not just above 3000 rpm. I am not sure what you mean by burnt section sticking above the piston top....do you mean part of the piston is chipped off or soemthing?

As far as driving the car that way, I don't think you are in any position to state this. It is my second car that I meant to have fun with and to learn how to tool around with. A cavalier is just a cavalier, nothing too big to worry about. I got the in order to beat the hell out of, and it has held its own.

Another thing I would like to point out is that the problem never occured while I was running nitrous. It has only occured this winter, several months after I had run nitrous. The ecotec motor has served me well in the past, and I expect it is a simple fix if the right tools are to be gotten.
You came here for a technical issue, who cares about the other points you raised, something is damaged in that cylinder, the use of nitrous points to detonation especially repeatedly flattening the plug, based on your obvious inexperience in this area maybe you should heed the suggestions posted! It only happens above 3k because that is when the rod starts to stretch slightly, causing some interference, pull the head and look!

snupytcb said: are you trying to compress water. depending on the motor head gaskets are known to go bad.

A:if the head gaskets are bad wouldn't the engine idle rough as well as drive rough? I have no power loss, no noise, no check engine light until my spark plug is hit over 3000 rpm, and it doesnt do this all the time. it had happened 3 times now and rarely do i press it past 3000 rpm. when it did hit it then came with the sound, loss of power, etc. then i fix the gap and everything was back to normal.

bobss396 said: Since this is peculiar to the one cylinder, my best guess is that you broke one of the top ring lands on the piston. The loose piece is bouncing around the combustion chamber and once in a while manages to get compressed.

Now you say that the plug tends to foul, you might have even broken a piston ring. I predict that once this motor is taken apart you'll find a broken up piston in the suspect cylinder, cylinder scoring and the rings will no longer be in one piece. The other cylinders may have latent damage which should show up in a visual inspection.

A: I am not sure about a loose piece. the plug has never been compressed when under 3000 rpm at all. i would think that a piece popping all aroudn inside would mean a condition would occur at all times, not just intermittenly and over 3000 rpm... i could be wrong of course. i appreciate all the ideas and suggestions and am looking into it.

maxwedgy said:

You came here for a technical issue, who cares about the other points you raised, something is damaged in that cylinder, the use of nitrous points to detonation especially repeatedly flattening the plug, based on your obvious inexperience in this area maybe you should heed the suggestions posted! It only happens above 3k because that is when the rod starts to stretch slightly, causing some interference, pull the head and look!

A: Yes I did come here for a teceh issue, and who cares indeed about the other points. You had brought up the point that I should not be driving a car "a way" so you brought it up. No shit something is damaged i am trying to figure out what excatly. And if you read what i actually said, I NEVER HAD NITROUS DETONATION flatten a spark plug. Get this out of your head. I had not run nitrous since August. No problem until Late December with the spark plug being flattened. I am indeed inexperienced but at the same time am not stupid. I am fairly knoweldgable about engines but came to this forum to get ideas about the problem, not people telling me a car should not be driven in such ways when it was bought for such purposes to begin with. On top of that, you do not rea what I stated the symptoms were. And as I stated in my first post, I think the problem may be a connection problem with the piston connection to the rod but am unsure exaclty how the two are connected, so you aren't offering any help. The other guys on here offered their suggestions and said nothing of whether or not a car was supposed to be driven in this way blah blah blah.

Please remember that I never once experienced any engine problems while running nitrous. I took off the nitrous as I usually do in the winter when I don't run the car. It was off in August. I did not experience spark plug problems until late December. I do not run nitrous so the nitrous is not the direct cause of the piston or whatever hitting the tip of the plug, but it may very well in my opinion be the long term cause of a connection problem with the rod and piston...

What is a long term connection problem with the rod and piston? You have no idea what you are talking about, talk about "Blah", you seem to have all the answers but the " right " one. When you have run 8.90's at 150 mph using the juice come back and tell me what I said is "blah". Good luck, obviously you don't need any advice from me! I said it shouldn't be driven with the existing condition! You just don't want to hear, for the second time, to pull the head! I said nitrous detonation possibly caused piston damage, not the detonation itself causing the plug collapse. It is this misunderstanding on your part that points to the inexperience I made mention of. Your intentional misspelling of my signature smacks of disrespect and if this keeps up you face a possible ban!

maxine wedgy states: What is a long term connection problem with the rod and piston? You have no idea what you are talking about, talk about "Blah", you seem to have all the answers but the " right " one. When you have run 8.90's at 150 mph using the juice come back and tell me what I said is "blah". Good luck, obviously you don't need any advice from me! I said it shouldn't be driven with the existing condition! You just don't want to hear, for the second time, to pull the head! I said nitrous detonation possibly caused piston damage, not the detonation itself causing the plug collapse. It is this misunderstanding on your part that points to the inexperience I made mention of. Your intentional misspelling of my signature smacks of disrespect and if this keeps up you face a possible ban!

A: It makes perfecet sense to me and other automtovie techies who have stated that my problem may be a loose connection with the rod and piston. You may ask them if you like. Do you want a cookie for running 8.90's at 150mph? Big deal. I could easily have bought me a corvette or something like that but i wanted something cheap and something to mess around with. I know I am going to have to pull the head and look inside, I never said I didn't. i was wanting to get suggestions on the problem beforehand because I like to investigate things prior to doing something since I enjoy talking about car issues and working them out. Don't cry and throw a temper trantrum about mispelling your name. I doubt I face a ban. I am not having problems with other members here as they offer suggestions and no judgements. How old are you again?

All I would like is to get some info from knowledgable people here who understand the desire for learning and asking questions in regards to engine troubles. It would be best if you did not reply to my help queries anymore, especially since you think you are some kind of better person for being able to run 8.90's or something. I am fully capable of attaining that with a car also, but could care less as I like to experiment with different motors and cars and see how they act.

As far as an update for other people, I was contacted by another person on another automotive forum stating that their Chevy Cobalt was experiencing the same problem after running it on track with the supercharger. They had opened the head and found nothing broken or slipping but found out that the threads on the head for the plug were badly stripped, causing the plug to be lower than normal. However, I do know this is not the case with my car since I have checked this area.

There is not a 'loose connection between the rod and piston'. If there was, the rod would have disemboweled some time ago.

Now, you obviously have a problem with people. I can see that in the messages you write, both in tone and in what you say.

I'm not going to tell you how to fix your car. You obviously have the answers to any question you post, and seem to only want to troll here.

I will tell you to be safe and not involve anyone else in your accident when you grenade the engine and throw oil all over the ground, and possibly start a fire in the process.

Another thing - it's not very smart to argue with a moderator. Maxwedge is such and he does have the power to ban, without needing to consult others. You'd be wise to heed that.

Give it up guys, the original post has got to be a put on. Besides who in their right mind would juice a Chevy Cavalier and expect some longevity out of it afterwards.

The problem you described is not uncommon with engines using an oxidizer. Like everything else, there is usually a right way, a wrong way, and some middle ground where things might seem alright for a while, but eventually turn out badly. That seems not only to apply to your four year old 134-inch engine, but the entire thread posted about it. There seem to be several problems outlined in the posted material, not all of which are related to the engine problem, but I’ll begin by addressing that one.


First, going lean under load and the subsequent potential for detonation (audible or not) can create all manner of damage in a cylinder, and it’s usually the softest parts which reveal the damage first, like aluminum pistons and aluminum heads. Piston tops can melt, crack, break out, or even be shattered. Heads can crack, and ring lands can be cracked or burned away. Beyond detonation, simply running lean under load can have serious and damaging results. Aluminum melts around 1,100º, and using an oxidizer and not adding the necessary fuel to keep the mixture appropriate can elevate momentary cylinder temperatures dangerously close to that point. The damage is not necessarily instantly obvious, and can have a cumulative effect. The engine may only now be exhibiting the symptoms of that kind of damage. People who have had a little experience in hurrying down the pavement one way, then idling back up the return road and waiting in line to do it all over again have heard, read about, and seen the kind of damage which can occur.



The second significant problem is that there was an apparent misunderstanding of the advice you were offered. The fact that you were advised not to drive it that way probably has less to do with whether or not you feed it with anesthetic, run it at 6,000 RPM cold, or even drive it off a cliff. I understood the intent of that advice as suggesting that you not drive it until you determine what the damage truly is, since the risk of further and potentially catastrophic damage is greater. I doubt whether anyone cares how you generally use the vehicle. I especially doubt that you’ll be criticized for racing it by a guy who begins the first 60-100' of his Sunday drives on the rear wheels only. The fact that you misinterpreted that advice as an admonishment for using your vehicle in a manner inconsistent with hauling groceries or delivering pizzas is not the fault of the advisor, but the reader.

The initial advice offered was sound. Using a borescope can reveal the conditions in the suspect cylinder without having to remove the head, possibly unnecessarily. The other potential causes offered also indicate that a scope might be very useful in assessing the damage more easily. The original response was intending only to save you some time, potential frustration, and prevent further damage from what might or might not already be a fairly serious mechanical failure. Even if the damage is not related to a piston failure, there is apparently something causing interference in the cylinder. The advice not to drive it in that condition is valid, regardless of the cause.



The third significant problem is that you chose to deal with the misunderstanding in a somewhat less than acceptable manner. Insulting other members is not allowed, and that is clearly indicated in the membership and forum posting rules. Further, while forum moderators are necessarily tolerant and thick-skinned, one might think that insulting a seasoned moderator would be a less risky proposition. That would be another misinterpretation. Maxwedge would often be among the first in line to banter, lighten up the mood, and otherwise try to have a little fun in what could otherwise be a fairly drab and mundane series of questions and answers. There is a point at which comments turn from banter to openly insulting. That point is usually understood and defined by a person’s judgmental ability or sense of propriety. Lacking that ability to judge a situation and act accordingly, other intervention is necessary, which is why I’m here.

All participants are in the AF forums are entitled to some measure of respect in the responses and feedback to posts, appropriate to the topic at hand. Any member who feels he or she has not been dealt with appropriately by any other member, regardless of whether either member is a first-time poster or a founding site administrator, should have a recourse. Given that the manner in which the misunderstanding was addressed in earlier replies, and that you chose not to use the private messaging system or other options available to you, the public forum is evidently acceptable in your estimation. Therefore, this reply is also posted in the public forum.

I’d suggest that you again read the advice offered and apply it. You’ll have at least a week to try some of the suggestions and attempt to determine the root cause of the engine problem. Hopefully, some of that time might also be spent trying to rectify some other problems. That week should be adequate to assess the damage. If you feel that you have been dealt with unfairly, you have those same options still available as a recourse.

At the end of that week, you should be able to post back with your results, and we can pick up the topic again and try to help solve whatever you discover.

I wonder what happened to NoGoodScallyWag.

The reason I don't like NOS on a stock engine is exactly the problems you are having right now .......the engine was never designed to take more than 30hp before major mods are to be made ( the reason why programers only give you maybe 20lbs. and 15 hp adds). There is an old farmers trick that some old school techs still use.......take a bill out of your wallet and while the car is idleing, put it to the tailpipe I gaurente the bill during a stoke will get sucked back to the pipe instead of away like it should. Next save that bill, you just found a compresion leak thath is causing a vacume on the exhaust side indicating you have a big problem.

"Leading cause of poor spelling- to much beer and exhaust"