Ok so I posted here looking for help a week ago and got it on the spot.

So now my question is, my cylinder # 2, the spark plug had broken and shattered in the head so I had vacuumed as much of the pieces out and now after gaping and installing only 3 of the spark plugs, the 4th one in cylinder # 2 isnt locking tight, it just swirls and doesnt want to thread in.

So I look inside and I see no threads for it to grip on to.

My question is how can I re thread the head for the spark plug to thread into.

Or does this call for a whole new head?

I also noticed scorching and scratches at the bottom on cylinder # 2, all other 3 cylinders look fine to me.

 

You can use a heli-coil or thread insert..

 

Thanks. Will a shop be able to do this without removing the head?

 

Anything is possible. But to be safe just pull it and do it right. While you're at it some people would say do them all.

 

Here.

I would want to pull the head to do it right. They basically have to bore it out with a different thread, then sleeve a piece of metal that will take it down to the same size as your plug with the correct thread pattern, etc. There will be chunks of metal after they bore it out, and if the head is on they could fall into the cylinder and cause problems. Pull it off and do it right the first time...

The scorching and marks in the cylinder is another thing that I would want to see close up with the head off. While they have it off re-threading things, I would check that problem out for sure.

 

Don't take a chance, get it done right.....any decent machine shop could can handle it

 

Yes please do it the right way.Else it could cause you a heck of a lot more money to repair.

 

I would take it all apart and inspect it, Make sure nothing fell inside the cylinder.

A machine shop should be able to heli-coil it. It cost me about 40 bucks for one of mine once. but i had the head taken apart already.

don forget to get a new head gasket and some ARP head studs since its taken appart.

 

whats the probability of the head screwing up again after its been helicoiled? Meaning is heli coil something that is temporaryily used?

 

it is considered a perminate repair. heli-coil makes a special insert for spark plugs. Go read about it on their website http://www.emhart.com/brands/heli-coil they aren't that difficult to install. if you are going to buy the kit check out recoil brand as helicoil now makes some parts of their tools from plastic.

http://www1.mscdirect.com/CGI/N2DRVSH?SISECT=0000000474

i would assume an auto parts place would sell you the kit also.

 

I personally would not use a normal heli-coil on a spark plug.

http://www.timesert.com/

I would use something similar to the time-sert stuff above. Heat transfer will drastically change using a normal heli-coil

 

I blew the plug out of my head a year or two ago. Had it Heli-coiled by my local shop for around 80 bucks. I've never had any problems with the heli-coil or the plug since, and I don't baby my car.

 

just like a lot of guys said have a machine shop do it so you know it wont be screwed up. A machine shop will also use a high quality helicoil so you dont have to worry bout that either