Spark Plug Blew Out?

[dkerley03]

Yes, you read this correctly. Spark Plug Blew Out?

I installed these plugs about six months ago, to replace a set badly worn from being in to long. The plugs went in with out a problem, and in tight. I was afraid of over tightening then.

The car had started running rough at idle the night before on the way home back from Ga to KY. I thought, maybe I had bought some bad gas.

The next day, I was pulling away from a red light, normally. No heavy acceleration and POP! It began to idle rough. My first thought was that something let go such as driveshaft, rod, crank or even a piston. It was a loud pop, like the sound of a shotgun going off. I pulled over and got out to check, found no leaks or pieces. My son was looking under the hood with me and asked about the loose spark plug wire, that is when I found the plug laying on the wiring harness attached to the strut column.

We regapped, put it back in tight and the car runs great again?

Has this ever happened to anyone else? I will check my plugs new every oil change to make sure they are still tight. This was a bit scary, thought I was going to need a new engine at first.

[OrganicMechanic]

check you threads!!!

you may need to helicoil the hole.

[Farbin Kaiber]

x2. The old plugs you took out could have been crossthreaded.

[dkerley03]

Threads, OK

Yes, thank you. We checked the threads and they seem to be in good shape. There was no shavings, scrap or residue on the plug threads. The plug threaded in smoothly, it didn't feel cross threaded?
I will keep a check on them all and if it loosen like this again, I guess i need to replace the head? Is there another solution, I know on VW Air cooled you can rethread or put an insert into a head?

[Farbin Kaiber]

Yes, you can helicoil the cylinder head. Some people can do it on car, some people have to pull the head. It all depends on how good you are.

[StereoInstaller1]

Helicoil was invented to make stronger threads for spark plugs in old aircraft engines, which were aluminum.

[devonjordan]

Helicoil was invented to make stronger threads for spark plugs in old aircraft engines, which were aluminum.

But you gotta make sure that the person sdoing it knows whats up, otherwise it blows out again, and costs you a new head... ASK ME HOW I KNOW!

[Farbin Kaiber]

How do you know?

[devonjordan]

How do you know?

LOL.

My S50 Head was helicoiled... it backed out and killed the coil in the process, 2500 later and she is all freshened up, with schrick cams...

[KevlarWeave]

Helicoil was invented to make stronger threads for spark plugs in old aircraft engines, which were aluminum.

Prove it.

[Jesse30]

you could have just not tightened them down enough. i did that when i first changed the sparkplugs on my e30 when i was like 14. i was scared about ruining the head. just make sure they're all tightened up.

[dkerley03]

Spark plug Blew out again!

It has been several thousand miles and a different set of plugs! But the same position blew out again! I was told at the parts store I could possibly heliocoil it for ($50) part or use blue locktite?

Heliocoil or Blue Locktite. which bears the least risk for the engine? I want to get several more months out of the head and in the mean time get a custom build to replace the existing head with?

Guidance from your experiens is appreciated. I am trying to keep the cost down as I am still rebuilding from my December accident.

Thanks All
Dennis

[euroshark]

I hate to imagine what mess could result from using loctite on a spark plug, but if you are feeling lucky give it a shot.

My money says you will need a helicoil for a long lasting repair or just a new cylinder head.

[devonjordan]

I hate to imagine what mess could result from using loctite on a spark plug, but if you are feeling lucky give it a shot.

My money says you will need a helicoil for a long lasting repair or just a new cylinder head.

Might just keep it in place long enough for him to get his other head ready.

I would have to agree, if you care about/want a long lasting repair helicoil, otherwise locktite that bitch and be done.

[dkerley03]

Helicoil!

I really prefer the idea of Helicoil, but I have no experience in how well that works. I am sure my shop/gaarage could do it.
I have heard and read never use locktite on aluminum! That it is permenant, I don't want to ruin the head for ever!
My big concern i whether a helicoil produces hot spots or heat issues with a head. Fifty dollars to buy the Helicoil is not really bad at all compared to the price of a head or rework.
So I understand, I can take car fo this properyly and probably get a few more miles out of it.

Thanks
Dennis