Had today set to do some work on the wife's car, a 99 Cavalier. Changed the air filter and oil, and was going to change the spark plugs as well. The car was still warm, so I left the plugs, and started working on my TA. I have an edelbrock performer rpm manifold in the garage, so I ripped off the stock one and got everything ready for the new manifold. At this point it started to rain, so I decide its more important to get the wifes car done and finished first. I touched the head on the Cavalier and it was cool, so I wasn't too worried about stripping the threads in the head. I change the first three plugs with no problem. Get to the last plug and the damn plug broke off inside the head! The plug threads and the ground strap are still threaded in the head. The plug broke right where the threads meet the nut/socket thing on the spark plug. I was to mad to do any more work on the car today. I have some ez outs which i'm going to try tomorrow. I hope i can get the threads out this way, and not break the ground strap either, wouldn't want it falling into the cylinder. If that doesn't work, I'm going to have to get someone else to get them out. I just hope the head doesn't have to come off for it.

I just thought i would do something nice and surprise the wife, but this isn't the surprise i had in mind. She'll be home from work in a couple of hours, I'll break the news to her then

Anyone have and tips or advice on getting the threads out?

Thanks

 

I'm taking it that the plug broke in half and that the internal parts of the plug that go down inside the motor are all still there and it's not like the whole thing - electrodes and all - came out leaving just the threaded part of the plug inthe head. If that happened then there may be crap already inside the cylinder.

If the plug just broke in half and its guts are still there and then you drill it get a fat easy out in there isn't there a risk that you'll end with fragments inside the motor from doing that.

Not much of answer I know but I'm concerned as to how you'd get an easy out down the inside of plug w/out the risk of some crap getting into the motor.

 

My suggestion is bring that cylinder to top dead center so that if anything does get in there you can vacuum a good amount out.

The only way I imagine you getting that out is to drill and chase the thread... good luck with it.

 

looks like someone is sleeping on the couch tonight. breaking plugs sucks.

 

When the plug broke, the ceramic portion that covers the electrode came out with the plug intact. The plug that broke looks just like a normal spark plug, with just the threads missing. I'm 99.99% sure nothing fell into the cylinder. I'm very lucky it broke the way it did, or else i'd have to pull the head for sure. I'm going to try the ez out method tomorrow. I pray that it works. I'd pull the head off a SBC in a heartbeat, but a DOHC 4 banger head is a little intimidating.

 

Managed to get the old plug out. Took an extractor and 4 feet of extra pipe to break it loose, but its out now.

Thanks again for the advice!