Spark plug. What is going on here?

[dinther]

I decided to inspect the spark plugs on my car just to verify the correct spark plugs are installed. It took me a while to actually find them as they look nothing like the conventional sparkplugs but thanks to the encyclopedia I found them after all.

I inspected from right to left and removed the highvoltage transformer thingy that is held in place by a single bolt. Once removed I could look into this deep shiny hole and at the bottom I could see the sparkplug head with a mark "B" on it. That matches the mark on the cylinder block. The second on was fine too but the third spark plug (far left one) was a different story.

While on the other ones the plastic tube leading down to the spark plug looks new and shiny plastic, the third one is covered in carbon deposits!



Also looking inside the shiny hole in the cylinder block you can see carbon deposits. Finally the plug in there does not have a mark on it.



My conclusion:

The third plug is of a wrong type and doesn't fit properly. As such it has been leaking thus causing the carbon deposits. It is a miracle the engine runs smooth and still did 40 MPG.
Also I suspect that the wrong plug might have done some damage to the thread in the cylinder block.

I really need some expert opinions on this one. I will not drive the car until I see this fixed. Also I like to know if all three plugs must be replaced at the same time or if just the bad plug needs replacement.

All pics:

http://vandinther.googlepages.com/Spark_plug001.jpg
http://vandinther.googlepages.com/Spark_plug002.jpg
http://vandinther.googlepages.com/Spark_plug003.jpg
http://vandinther.googlepages.com/Spark_plug004.jpg

[Insightful Trekker]

Clean the carbon off the ignition coil's tube and inspect for damage from excess heat. Should a misfire begin at any point in the future you now know where to look first.

You don't specify the exact nature of the "wrong" spark plug. Even a correct spark plug can do the same sort of thing if not correctly tightened. IF the plug's thread reach was insufficient such that the deeper part of the threads in the cylinder head are caked with combustion deposits then _carefully_ running a thread cutting tap down the hold to cut out the deposits should be done before reinstallation of a correct plug.

If any of the threads ripped out when removing this wrong spark plug then careful inspection should be done _before_ the above to determine what course of action would be the next best step. What action depends of many factors, cost ususlly being of prime concern. The _absolute _ best would be to remove the cylinder head for machine shop repairs. But again it always depends of the specifics and for many cases while its "better" its not always necessary.

HTH !

[Insightful Trekker]

Also:

Flooding the spark plug well with a suitable penetraiting oil _prior_ to you attempted removal, allowing sufficient time for the oil to penetrate, _and_ gently using _hand force only_ to remove the plug can prevent further damage. 1cm+- deep is sufficient. Carbon is now caked in the threads. Forcing the plug out can also damage threads.

When removing, should the plug become tighter, gently retighten to help draw the oil deeper into the threads and soften the carbon. Then proceed with removal. This process could take several repetitions before the plug is sucessfully removed. And it value for possible prevention of thread damage should not be underestimated (take your time). However, its usefullness has its limits and after more than 10 repetitions, if increasing progress is not being made, the damage may be too great to overcome.

Should an excessive amount of oil be used (sometimes beneficial) then the engine should be cranked with all spark disabled and the plug in question removed to blow out the excess oil. Hydrostatic lock will severely damage the connecting rod. Remember to cover the hole with a rag before cranking

HTH!

[Dougie]

If it ran ok, then probably nothing's broken like, for example, the pistons. There are only a couple of plug sizes (big and small), so if it fit in there at all then it's probably ok from the threads-fitting viewpoint. But it might have been cross-threaded, which would be a problem. Plug threads can be repaired with a heli-coil, although it is a bit of a hassle...

My guess is that it's just loose.

[dinther]

But what would have caused the carbon deposits? That must have been due to some kind of leakage from the cylinder right?

[dinther]

After all the jubilation about Honda service in the US, I thought I could not go wrong with an official Honda Dealer here in New Zealand.

It turns out that when Honda says they check spark plugs, they actually mean they check a single spark plug when there is no reason to suspect faulty ones. That is outlined in their procedure manual. So they refuse to take any responsibility for the fact they completely missed this nearly burned out one despite the fact I had reported that the reason for the service check was a high fuel consumption.

It now also turns out they put 10W-30 oil in the engine as it is the standard oil they use for all Honda cars. But the Insight manual is quite clear about the 0W-20 or at least 5W-20 oil.

Finally they thought it prudent to water blast off the fresh coat of wax that had been applied before the car went to service. They tell me they water blast all cars as a matter of service. Somehow I am not all that grateful for this.

I really wonder what else they have not done or done to the car. How can I possibly trust these guys to do a proper CVT flush next? Am I unreasonable here?

[Patrickmilburn]

As there are only 15 Insights in all of New Zealand, I suppose they just aren't familiar with the unique aspects of this car!
You may well be better off doing basic routine maintenance yourself.

I suggest you order a Fumoto valve as discussed elsewhere on this site to protect the delicate threads in your magnesium oil pan and start changing your own oil and filter using the proper 0W-20. Perhaps you can also order a new set of plugs from a supplier like Majestic Honda in the U.S. and save yourself some money as well.

[Insightful Trekker]

Originally Posted by dinther

Am I unreasonable here?

Well....

Fixing MPG is nare impossible. Particularly hyper MPG since almost _everything_ is against it.
(driving style being a significant part of the equation)

But why a spark plug check _without_ driveability symptoms is of any value is beyond me. Particularly if there's less than 105K US miles on the car.

Weight of the oil issues has already been answered eariler.

Water "blasting" off wax ? Hmmm. IMO musta not been much left to remove.

DO NOT FLUSH a transmission. ALMOST ALWAYS not needed and can actually _cause_ problems if not done correctly. Three fluid changes back-to-back with a brief engine / transmission run up in-between is more than sufficient to bring the quality of the fluid to "near new".


HTH!

[dinther]

Thanks for all the advice, I will replace the transmission fluid several times and see what results I get.

As for the spark plug, I need at least one new plug stamped "B" which according the encyclopedia is a 12291-PHM-A01 it is impossible to buy them in New Zealand and importing via Honda is stupidly expensive and many times the price of the ones listed here: http://www.hondapartsnow.com/model/g/33 ... _coil.html

I think I may also order a new coil while I am at it. But sadly these guys don't ship outside the states.

So three questions:

1 Do I need to replace all three plugs when I really only need to replace one faulty one
2 Does anyone know a parts reseller that will ship to New Zealand
3 If not, is anyone willing to help me to buy those parts and send them to New Zealand. (I'll pre-pay for all the expenses of course. PayPal preferred)