Is a Dented Spark Plug Bad?
- Thread starter campoj2
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Campo,
something's not right in Toyota land here. Either you know more and are looking for a 2nd opinion on a guess from someone here, or you're settling for an awfully low level of information on what happened to your engine. Or, they're simply hoping that you eventually come to the conclusion that lightning struck you twice when they know full well they did something.
I'd be interested in the spark plug picture, but frankly a piston hitting the sparkplug after the engine's been running fine means the piston is disconnected from the crankshaft. This is a positive clearance engine. Further evidence of this is that they saw nothing in the cylinder using a borescope (assuming this last is true - that they looked in the cylinder with a borescope vs leaned over and saw a dent via the sparkplug hole). So according to the borescope there's nothing untoward IN the cylinder (a valve and chunks of it), which means the piston hit the plug from a broken wristpin, etc.
So. This is where I think something's not right with your dealer telling you. If the piston is not connected, then their compression test would have produced some serious noise. My conclusion is they either did not do a borescope inspection or they did not do a compression test. Pick one.
So, did the sparkplug come out in one piece or are their chunks missing?
DougM
something's not right in Toyota land here. Either you know more and are looking for a 2nd opinion on a guess from someone here, or you're settling for an awfully low level of information on what happened to your engine. Or, they're simply hoping that you eventually come to the conclusion that lightning struck you twice when they know full well they did something.
I'd be interested in the spark plug picture, but frankly a piston hitting the sparkplug after the engine's been running fine means the piston is disconnected from the crankshaft. This is a positive clearance engine. Further evidence of this is that they saw nothing in the cylinder using a borescope (assuming this last is true - that they looked in the cylinder with a borescope vs leaned over and saw a dent via the sparkplug hole). So according to the borescope there's nothing untoward IN the cylinder (a valve and chunks of it), which means the piston hit the plug from a broken wristpin, etc.
So. This is where I think something's not right with your dealer telling you. If the piston is not connected, then their compression test would have produced some serious noise. My conclusion is they either did not do a borescope inspection or they did not do a compression test. Pick one.
So, did the sparkplug come out in one piece or are their chunks missing?
DougM
I think he said in an earlier post that it just bent the metal terminal over onto the electrode?.
Campo,
Who is Big Jim and where does he work? I know a couple of honest mechanics in your area. I agree with Doug abut the noise. If it was running fineand now isn't what happened before, during and after the spark plug got bent / smashed.
Who is Big Jim and where does he work? I know a couple of honest mechanics in your area. I agree with Doug abut the noise. If it was running fineand now isn't what happened before, during and after the spark plug got bent / smashed.
- Thread starter
- #25
Doug,
2nd opions are nice and that is what I am looking for. They did a straight up engine swap, nothing else that required removal of anything, the swap was complete and the motor ran. I don't think they would grenade an engine on me, I service 5 vehicles at this establishment and never have had an issue.
How common are broken wrist pins?
The tip of the plug is bent and is now touching the electrode. The plug is in one piece.
Cappy, when are you going to be in DelCo?
2nd opions are nice and that is what I am looking for. They did a straight up engine swap, nothing else that required removal of anything, the swap was complete and the motor ran. I don't think they would grenade an engine on me, I service 5 vehicles at this establishment and never have had an issue.
How common are broken wrist pins?
The tip of the plug is bent and is now touching the electrode. The plug is in one piece.
Cappy, when are you going to be in DelCo?
Last edited:
even with a broken wrist pin the piston cannot physically contact the a spark plug of the proper length.
Just went and looked at my spare 1FZ head, the furthest tip of the plug is recessed is the combustion chamber by at least a 1/4" more likely 3/8", the combustion chamber is smaller than the piston, the piston cannot get in there,
the plug was dropped before install or there was an object in the cylinder,
only way I could see the piston kissign the plug is if the head was severely decked, compression would be super high though,
Just went and looked at my spare 1FZ head, the furthest tip of the plug is recessed is the combustion chamber by at least a 1/4" more likely 3/8", the combustion chamber is smaller than the piston, the piston cannot get in there,
the plug was dropped before install or there was an object in the cylinder,
only way I could see the piston kissign the plug is if the head was severely decked, compression would be super high though,
x2.
The piston would eat itself trying to squeeze into the combustion chamber. With the scenario you describe, you should see valve damage as well. Is the piston intact? A bore scope cannot show 'nothing'. You can get a feel for the condition of the cylinder/wall at least.
This is not kosher.
