Crazy8

I think i will have to use a spark plug thread chaser to see if i can get my spark plug to go all the way in the hole. I need to know what exactly i need to do. I dont want to screw anything up. The plug right now goes to a certain point and stops, like it is cross threaded or something. Its not all the way down in the hole because it doestn look like it and the exhaust leaks around it. Do I just take the thread chaser and screw it in the hole and when it wont go anymore should i keep it going to see if it fixes it or should i stop. I really dont want to mess things up. Thanks.

shoebox

What you really want to do is get the chaser started as the original threads were. That is going to be the hard part because there is usually little room to see. A mirror might help if you need it. The best way would be to chase them from inside the combustion chamber outward, but there is no way to do that with the head on. There are not a lot of choices with the head on the car.

Crazy8

so should i just feel around till the chaser goes in?? Once i have it in, assuming i get it in, should i screw it in till it hits the cross threads or should i keep going ??

shoebox

Your problem is going to be finding the original threads. The chaser is probably going to want to follow the cross threads.

I found a tool in a NAPA flyer today that is called a "Back-Tap" tool. It rethreads from the inside out. Never seen one in use, but looks like the ticket if there is enough room to use it. It also keeps shavings from getting into the cylinder.

Crazy8

shoebox, i dont think i am going to try to fix it. I dont want to mess something up more than it already is. Do you think that if i took it to a GM dealer that they could fix it for me? How much do you think they would charge? Thanks....

shoebox

I am sure they will be glad to soak you (uh, I mean, work on it) for what they can get. They will probably try the same things and if they mess it up, they will say the head needs to come off and be willing to charge you hundreds of dollars more. If someone does work on it, you should ask exactly how they are going to try to fix it.

I don't have a clue as to what they may charge. It all depends on how much time they invest.

Crazy8

Thanks for the info.....well i have an appointment for monday morning to see what they think. I pray to God that it isnt anything major

PGR

I chased the threads on my #7 spark plug hole, without removing the the head or exhaust manifold.

The trick was using an actual Tap, a box-end wrench, and a small hand mirror. From under the car, you place the tap into the old threads, and start the tap by had. Use the mirror to insure the tap is aimed straight into the spark plug hole (its easy to go in at an angle and cross thread). Once the tap is started, give it a quarter to half turn with the box-end wrench, back it out a quarter turn, and repeat. Also, smear some light grease into the flutes of the tap - this will catch any chips and prevent them from falling into the combustion chamber.

If you are not very dextrous and have no experince with a tap, leave it to a professional. Its easy to mess up those aluminum heads.

A good mechanic at a dealership should be able to do this in less than an hour total. Took me about an hour out in my driveway. Removing the head should not be neccesary. They may need to unbolt the motor mounts an jack the engine up some, depending on which cylinder.

Crazy8

i am leaving it to the professionals....they just better not screw me or i will be PISSED ...thanks for the info and i will keep in mind that it shouldnt take very long!! Thanks.: