Spark plug blew out the hole!!!
 

so i had new exhaust installed on the truck today with a 1 in 1 out magnaflow, i made it about 6 miles down the road and then the number 1 spark plug went pop. im curious if the new amount of backpressure the truck has caused this or if it was just a freak coincidence. Btw its a inline 250 motor if that helps any:waah:

Re: Spark plug blew out the hole!!!
 

It seems like this is an odd coincidence, the exhaust would only create pressure during the exhaust stroke and the exhaust valve would be open. The highest pressure would be during the compression stroke. I have a sneaky feeling that your plug hole was in bad shape, if the plug will not tighten up you made need to do a Heli-coil thread replacement. Most good auto part stores will have them. Good luck and God bless

:flagw:

Re: Spark plug blew out the hole!!!
 

Or the plug was loose to begin with...

Gary

Re: Spark plug blew out the hole!!!
 

well i did just replace the plugs last monday lol, maybe i over tightened or not enough, guess well see with the new plug :smoke:

Re: Spark plug blew out the hole!!!
 

Man that sucks, like Arizona said you can usually get lucky and do a heli-coil but hopefully it didn't take all of the threads with it on the way out.

I had a Ferd V10 back in the day that was known for doing that but I was lucky it never happened to me before I sold it. Heard some horror stories of guys having to replace multiple sets of heads though.

Re: Spark plug blew out the hole!!!
 

well the whole plug didnt blow just the white part, the rest is still threaded in the head, so im lucky i can get it out with a socket

Re: Spark plug blew out the hole!!!
 

Possibly it was bumped during the exhaust install and blew out.Or maybe it was just a factory "bad plug".Glad to hear it was an easy fix.

Re: Spark plug blew out the hole!!!
 

Oh, you're Golden then. Just pop it out and get some good quality pugs (Not sure what you were running before) and pop em in. Like panel said, if it got bumped and cracked it will blow out.

Re: Spark plug blew out the hole!!!
 

It prolly didn't "blow out"... it "broke off".

Gary

Re: Spark plug blew out the hole!!!
 

Lots of good advice goin on here. Check your plug socket, it needs to have a rubber insert, it will help you not break plugs when you are putting the El Paso cinch on em.

Re: Spark plug blew out the hole!!!
 

I think "Blow Out" sounds cooler :lol:

Re: Spark plug blew out the hole!!!
 

The only time I've seen this was with a cracked head. Coolant gets into the Cylinder and cannot be compressed. The term to cover is is "Oh you've hydraulic-ed your plugs."

Re: Spark plug blew out the hole!!!
 

We were at an All Harley Drag race about 10 or twelve years ago in Temple Texas. Joey Mancuso blew a plug out, It hit a tree limb about 3 inches in diameter above the stands and it fell into the stands right where no one was sitting and it was pretty crowded. It scared a bunch of people though:lol:

Re: Spark plug blew out the hole!!!
 

i was using ac delco plugs, i put a new one in and so far so good. only bad thing about it, is i think some of the plug might have made its way through the radiator :(

Re: Spark plug blew out the hole!!!
 

about 7-8yrs. ago a kid in my Son's band had a crappy little Furd Aerostar that blew the center white porcelain part of a plug out of the metal plug body. The base of the plug was still screwed in the head and the white part was in the wire boot hanging on the wire. Replaced it with a new plug and away he went. Think it was an Autolite------- my Son still has it. Never seen one do that in 50+ years.

Re: Spark plug blew out the hole!!!
 

prolly happened when you were torquing the plug, if you don't keep the socket centered then they will crack. I've done this a few times....and it was always after the parts store closed so I had to wait till the next day or put an old plug back in.

Re: Spark plug blew out the hole!!!
 

I have seen them blow-out before, but it was on a blown street rod. The white insulator is just crimped intop the top of the metal fitting.
I have even seen them un-screw and pop the entire plug out, but that was on a I6 Furd. Makes a horrible racket doesn't it?

Re: Spark plug blew out the hole!!!
 

the noise was embarrassing to say the least, but yea all that was left of the plug was the threaded part. :metal: