Blown sparkplug

[Uncle Dave]

Greetings all,<br /><br />I recently solved an overheat problem with manifold, exhaust riser, thermostat. The riser was especially rusted and corroded. Almost closed off completly wher the riser meeets the manifold.<br /><br />Then on trial, it ran excellent for about 30 minetes. All gaguges normal. Then the porcalin blew out of a spark plug. Limped back in with the "hole" swishing air.<br />Any ideas on why such a thing. The parts guy said it was an old plug. Because of the printing on the plug. It was an AC. The motor (Merc. 140) was running really sweet right up to the blow out. All the procalain came out. The metal part stayed in the head.<br />My only thought other than plug fatigue would be cross fire from the dist. cap.? I am changing all plugs and the dist. cap.<br /><br />Any thought or suggestions prior to firing up again would be much appreciated.<br /><br />Uncle Dave.

 

[vipzach]

Re: Blown sparkplug

There was another guy on here a few months age that had the same thing happen to his plug, but his was a champion. If I remember right it finally decided it was a bad plug. I would make sure there no parts left in the cylinder and replace them all and hope for the best. Do a search and see if you can find his thread.

 

[fastimz9]

Re: Blown sparkplug

I had this happen on my car. The porc. cracked and blew the electrode out the end. They had about 50 miles on them....They were Autolite Plat. plugs. Sometimes we just get plugs that fail....

 

[jvr440]

Re: Blown sparkplug

I had this same thing happen on my car too, except my plugs were 1 year old Champions with 20,000 miles on them. Car was running great with no sign of any problems and the plug just let go and blew out the porcelain. I was puzzled why it would do that after a year and never did find any reason other than a faulty sparkplug. Replaced them all and no problems since.

 

[Silvertip]

Re: Blown sparkplug

Funny you should mention this. My fishing buddy had this happen on his tow vehicle about three weeks ago. 61,000 miles and the porcelain blew out of the housing. Only problem was the plugs were in a 1991 vehicle which is now 14 years old. Never been changed. The mechanic twisted off three of the housings trying to get them out of the head. He fortunately extracted the pieces without having to remove the heads. There's a lesson here.

 

[Uncle Dave]

Re: Blown sparkplug

Thanks to all that replied.<br /><br />I talked to my auto mech. He said sometimes plugs just let go like that. Usually does not cause a problem if attended to immediately.<br /><br />So I put in a new plug and fired the old boy up. It ran slick as ever. It seemed to have not have any ill effects.<br />Uncle Dave