Blown Plug---2X, How Can I Fix

[chris chick]

That pesky plug under the passenger side wheel well, 2 weeks ago, somehow it worked itself free, plug bloken and fused to boot.

Replaced it and thought I had the problem licked....today, it's out again, I was able to let the engine cool down enough to hand tighten and get back home.

I'm realizing there is more to the problem than meets the eye, could the threads be damaged somehow in the block and I'm fooling myself thinking the plug is tight. Anyone ever deal with a problem like this???

any help appreciated,

chris

 

[zukman]

look at this and then do a little research.
http://www.consumeraffairs.com/automotive/ford_spark.html

 

[bisjoe]

I'm realizing there is more to the problem than meets the eye, could the threads be damaged somehow in the block and I'm fooling myself thinking the plug is tight. Anyone ever deal with a problem like this???

any help appreciated,

chris

I had this problem before, in fact was about 400 miles from home. I used some foil wrap from a stick of gum around the threads to get it back in tight enough to get back home.

The threads are probably damaged, but you can try spraying the area with WD40 and trying again, only by hand until you feel that it's in right. Sometimes even removing the washer will allow more contact with undamaged deeper threads. There may be a risk of compression linkage or even altered performance due to the tip being farther in than normal but when I have done it on older cars never had a problem.

The real fix is a heli coil insert. A slightly larger hole is tapped, and a stainless steel thread coil inserted to accept the spark plug. While this can be done on the car on easily accessible plug holes, with care, on the one you have trouble with it would require head removal to do. That's safer anyway to avoid metal in the combustion chamber.

 

[chris chick]

Well, looks like a couple of threads on the head are damaged. I popped into Autozone and grabbed a rethreader for $7, gonna slow with it, like I would a tap and die and see if I can get the plug to seat. I honestly don't think they are damaged to badly.

Right now, the plug only goes in about 2 complete turns before stopping, it goes for about 100 miles, and then I can hear the tell tale sound it's going to pop.

Anyone ever use one of the plug re-threaders???

chris

 

[gijoecam]

look at this and then do a little research.
http://www.consumeraffairs.com/automotive/ford_spark.html

Those are a completely different vehicle with two completely different engines that have two unrelated issues with the head/spark plug design. It's like comparing apples to rabbits.

Don't waste your time with the rethreader... the rethreaders aren't a viable solution IMHO.

There are two possible solutions in my book: A Timesert BigSert repair kit sized to the hole/plug you have, or yank the head and have it rebuilt. Anything else will eventually fail again. Two threads aren't going to hold very long.

-Joe

 

[chris chick]

Joe,

Thanks for the reply.

I am hoping the rethreader works, the plug is actually only catching on the first 2 threads going in, then I'm hitting the bad spot. I hope easing it a 1/4 turn in, then out, then another 1/4 I can get past the bad spot and allow the plug to seat deep......research turned up your suggestion, along with the Heli-Coil kit.

I'll give it a crack first thing in the am.

chris

 

[chris chick]

HeliCoil Kit Does the Job

If anyone ever strips a plug, I can highly recommend the HeliCoil Kit.

At first it seems a bit duanting, tapping a larger hole in your aluminum head, but once you get the balls to attempt it, it's as easy as pie. Almost fool proof.

And a very complete remedy to a stripped plug. Can't beat it for $30.

 

[OldRedB2_84]

Glad to see you got it fixed