Piece of spark plug in fell in when changing sixth spark plug [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: Piece of spark plug in fell in when changing sixth spark plug

08-30-2011, 03:12 AM
Longtime reader and first time poster here. Yes the worst thing that could have happened to a guy trying to save money has happened. I was changing my spark plugs and when I was lifting the sixth spark plug out a piece of the porcelain broke off and fell inside the cylinder. I have a snake camera and confirmed that it was indeed down there but it is in several pieces. My first thought was that I am going to have to get a mechanic to take the head off to remove the debris. My longtime mechanic told me to fully disconnect the ignition coil and run the engine with 5 spark plugs and the porcelain would blow out the top and the rest would exit through the exhaust but this sounds a little risky to me. I don't know which route I should take for this issue. Any helpful advice would be great. I will also add that this experience has convinced me that I should not do my own auto work. Thanks in advance for any feedback!

08-30-2011, 03:27 AM
Sucks, unless you can guarantee with the scope and a vacuum that all the pieces are removed you will have to remove the head or else the pieces will eat away at the rings and cylinder wall.

08-30-2011, 05:57 AM
You kind of have 3 methodes to try, 1 will defenatly work. What I would try first is find a 1/2" to 5/8" rubber or flexable tube about 20" long, tape it to the end of a shop vac hose, or do as the mecanic suggested, or pay big time to have the head removed.
Good luck with it and let us know wich route you took.

08-30-2011, 09:48 AM
Maybe you could turn the engine by hand at the crankshaft bolt and bring the piston up and use a vacuum to suck it out. Did that once on an old chevy motor.

the roadie
08-30-2011, 10:21 AM
I'd bet compressed air through one of those 1/4" blow gun nozzles that can stick down there will make the chunks exit through the plug hole. Where else can they go?


08-30-2011, 10:50 AM
I'd bet compressed air through one of those 1/4" blow gun nozzles that can stick down there will make the chunks exit through the plug hole. Where else can they go?


Depends on if any valves are open... hopefully not an intake one. :)

Id try to vacuum it out if possible.

the roadie
08-30-2011, 11:02 AM
Depends on if any valves are open... Oh, I feel stupid. :o Thx. :bonk:

11-28-2011, 11:15 AM
Sorry it has taken me so long to reply. I took my mechanics advice on this issue and started the car with the sixth plug out. A few pieces of the spark plug ceramic blew out of the cylinder and the rest made an exit through the exhaust. I put the car in the shop because it was running a little rough after I did this but my mechanic called me the next day and said the car was running great. Im guessing the compuiter just had to reset? I haven't noticed any loss of power or any other major issues. I just want to thank you all for your helpful suggestions.

11-28-2011, 11:29 AM
Oh, I feel stupid. :o Thx. :bonk:

Do not feel stupid because you are right. Just rotate the engine by hand until both valves in that cylinder are closed, then install a copper or aluminum tube on a blow gun and put it down into the plug hole ( use as small a tube as possible so there is room for the porcilen pieces to come up the plug hole past the tube) you can use the scope to confirm that they are gone. If that does not work rotate the engine untill the exaust valve only is open and do the same thing. If the pieces are too big to come out this way you might have to do as the mechanic said and start the engine( this will cruch the porcilin till it is small enough to go out the exhaust valve. )
After starting the engine use the scope to look in the cylinder to confirm that there is no residual damage. If there is then you might have to have the head removed but if it were me it is worth the chance.

11-28-2011, 02:09 PM
I think vac 1st then turn the engine to bring it up while vac.Turning before vac or using compressed air can only push some on the cylinder walls and sides of the pistons before the top ring.

11-28-2011, 02:41 PM
Im glad the outcome was a successfull one for you.

Now my question is how can one stop this from happening, short of not doing it yourself?

Again, this is a job within the scope of most of us here, and accidents do happen. I feel that taking this to a mechanic or *gasp* the dealer is insane thinking just to have 6 plugs replaced, however you do run the risk of an accident happening.

My wifes 05 is upcoming for this (80k something miles) and I am not wanting to take it to someone to do it, and at the same time I dont want this same thing happening...

what steps can be taken to avoid anything falling down into the cylinder?


11-28-2011, 02:51 PM
I've never had a plug crack into pieces on me. I did have one on my old car crack above the hex (which was making the engine miss), but that was no big deal as it still unscrewed just fine.

Never occurred to me that this could happen :ugh:

11-28-2011, 09:54 PM
Indeed this rare, just take your time removing the plugs and you will be fine.

11-29-2011, 12:19 AM
Unscrew the plug just a half turn, then use compressed air to blow out any dirt, if you're worried about it.

Wear safety glasses.