First Time Swapping Sparkplugs
 

Hello everyone! I was recently gifted a '96 Blazer and have been trying to make small fixes.
Upon learning that the Number Six Cylinder was misfiring I took a peek under the wheel well and much to my delight I found out that the sparkplug wire was severed!
So I decided that I should change the sparkplugs and the wiring for them. Whilist trying to get Six-Four-Two out each one snapped like so, leaving the hex in the sparkplug receptacle...
What am I doing wrong? I'm going lefty-loosy counter-clockwise and every time I do it, they snap. I can't even get them out and I'm afraid if I try really hard/use my impact drill I could accidentally mess up the threading!
I blasted some PB Blaster into the sparkplug areas and I'm gonna let it soak for awhile.

But am I doing something wrong? They keep snapping, leaving the 5/8ths hex intact.
https://cimg4.ibsrv.net/gimg/blazerf...56eab2c34f.jpg

I can only guess that they are snapping off because the axis of your socket is slipping to an angle that is no longer parallel to the spark-plug. The spark-plugs come straight out of the block and are not angled. Because it is kind of tight in the engine compartment, I could see the socket easily slipping to the side. You might have to get creative with how to apply torque to your socket.

Letting the PB Blaster sit overnight should definitely help. I also like the CRC Freeze Off as its cooling action will crack the corrosion and allow the penetrant in.

Hope this helps. Keep us posted.

The only time I've ever done this is on an old 350 and it was adamantly my own fault. By not seating the socket all the way down onto the plug before trying to loosening it, it made the socket tweak sideways as soon as I applied torque and put stress on the porcelain, thus causing it to crack off the base of the plug just like the ones in your photo.

So long as you can still get your socket on the hex portion of the plug, there shouldn't be any issue loosening it, you just might have to use a magnet on a one of those extendable stick thingies to fish it out, since you don't have the tip of the plug to grab onto any more. Luckily that's what's physically threaded into the cylinder head, not the porcelain part you broke off.


By the way, put AC Delco plugs back in it, stay away from those Bosch thingymajigs... just my opinion...

Thank you, I'm asking on a different place too and it looks like it might just be the angle I'm trying this from.
Now that I think about it, I might have to get an extension or a breaker bar something to get a better angle.
I was thinking maybe even a Swivel Head Rachet to help getting a straighter-shot on the hexhead.


I got replacement AC Delco! I'm not going with anything else as the Internet and General Consensus is AC Delco>Everything

Never heard of CRC Freeze Off, I'll have to look into it.

Thank you again!!

We usually work the spark plugs through the wheel well in the Blazers.
It helps keeping the wrench at a good angle towards the spark plus. Just needs quite a bit of an extension.
With a breaker bar you can access some of the plugs easily.

Also I do "anti-seize" (sparingly) onto the spark plug thread before putting them in.

Are you aware of the existence of spark plug sockets? These have a rubber insert that helps protect the spark plug porcelain. I think you might be going at this with a simple deep well socket. Irregardless of what you use, the socket must be on straight when applying torque or the porcelain will be cracked or broken. If this happens, broken or cracked porcelain will cause your new spark plug to misfire. Sometimes you need to use a "swivel" and an extension to keep the socket on straight. The swivel needs to be on the spark plug socket, not on the ratchet handle. My spark plug socket has the swivel built into it. Good luck!

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Thank you both for your contributions. I think I'll go with an breaker bar or/and an extension so I have the best leverage. I was trying to get them out just a few minutes ago and I was able to get one out! I think it was because I put the swivel on the sparkplug socket instead of the ratchet handle. What a goofy mistake I was making before. Its mostly the angle that I'm working with since its cramped underneath the wheel well even with the car jacked up a little bit.
I'll get both at work and come back to it later, hopefully I can get this thing rolling soon!
I'll keep you guys updated, again, many thanks for your contributions!!!

EDIT: I'm going to put anti-seize on the sparkplug threads before I put them back in, but should I also dab a little on the receptacle socket too? Also, I checked on Oreilly's Website and it said the replacement plugs I got are a guaranteed fit. Are they plug and play or do I need to do any kind of finagling at all to the sparkplug? Sorta related too, when I got my car diagnosed it said that I needed to change the B1S3 Oxygen Sensor. I feel like it could be related to the sixth cylinder sparkplug wire being severed. Would my hypothesis be correct?

Use anti-seize VERY sparingly. It's electrically conductive, so you don't want it running down onto the insulator.

Probably going to need a catalytic converter instead of a post-cat O2 sensor if it's been running very long with a dead misfire. Contrary to popular opinion, O2 sensor codes seldom mean a bad O2 sensor. You want dielectric grease on the wire terminal (not antisieze). Other than checking the gap, the spark plugs should be ready to go in. Be careful not to crack the porcelain. Good luck!

I hope I don't have to replace the catalytic converter. Is it a hard job? The part doesn't seem super expensive... I took a peek at the sensor and it doesn't seem to be fouled either. I haven't used my circuit tester on it though so we'll see what happens when I try that. I dunno how long it's been running with the misfire so hopefully I'm in the clear.

EDIT: Thank you so much to everyone!!!! I managed to get the sparkplugs out with the swivel on the socket + 20in extension + breaker bar!!! (drinks to those who suggested that)
I also tested out the O2 Sensor with my circuit tester... The receptacle wires lit it up but the O2 Sensor end itself did not light up even though it was plugged into the receptacle...
Am I doing this right? Is the O2 Sensor borked?
Tomorrow I'm going to install the new Spark Plug Wires, the packaging says they come pre-greased so that's good. Then I'll install the new sparkplugs and we should be golden!
Are there any tips for the installation of the sparkplugs? I know that you cannot cross-thread as it will screw everything up. I heard there was a trick with a piece of 1/4 Gas Tubing. I think I have some laying around I could use...

Again, many thanks to everyone helping this newbie out!!!