Sparkplug Removal Technique

[ARCHINSTL]

Well, this is something I'd never heard of before...
Like many, I get the Rockauto monthly newsletter. This month there is a feature on sparkplug removal, so I spent 4 minutes watching it.
What I'd never heard of before was the wrench saying that, with aluminum heads, you just break the plugs loose for 1/4 of a turn or so only. Then start the engine and rev it for a tad. Then turn it off and then unscrew the plugs, hopefully by hand.
The reasoning here is that there is a ring of carbon at the end of the threads where the plug inserts, and breaking the plug loose and then revving the engine blows the carbon out of the cylinder and away from the threads.
Now, he was doing this on the new-fangled coil-on-plugs used in some (all?) cars nowadays.

Is this a better way of removing plugs for our mature engines?
Tom M.

[splatterdog]

Not many plugs have threads extending in to the combustion chamber, at least as far as I've seen. Yes it can happen. I worry more about the last person that touched them. Most plugs are now recessed in the head, making for a great dirt trap. I do stop after a few turns to re-blow out the hole on those, especially gasketed plugs. The gasketed plugs trap debris that often doesn't loosen up until the plug is turned. I've seen lots of DIY'ers and shops drop lots of grit in the cylinder and plug threads. Improper torque too.

Here's some tricky late model plugs brought to you by the inventors of cab off engine repairs...[url]mms://multimedia.ford.com/seopts/Tech26_250k.wmv[/url]

[Petros]

I saw the same video, It can be a big problem on some cars. I have never had this problem with any car I have owned except the newer cars with full solid state ignition, the spark plugs last too long I think. I had this problem with my daughter's 2001 Suzuki Esteem. I bought it cheap for her because someone had managed to get some gravel in the engine (likely from falling into the chamber from being deep in the spark plug wells as Splatterdog notes), it did a lot of damage to the pistons and combustion chamber. This car has the distributorless system with 4 small coils (which btw, have turned out not to be too reliable, I have to replace two of the four coils in the last 2 years).

Rebuild parts were VERY costly for the Suzuki (very unlike our Tercel), so I bought a complete running engine from a wrecking yard (for less money than a gasket kit!). It had about 120k miles on it (same as the car we bought), and it appeared to have the original spark plugs. They were literally frozen into the head, I could not even get them to turn at all. I put penetrating oil down the wells and really reefed hard on them with my big breaker bar. I had to work them back and forth once broke free, I figured there was carbon built up on the threads and it allow the penetrating oil to get down the threads. But there was a few I was afraid I was going to break off in the head, not a good situation at all.

I have ALWAYS used anti-seize on spark plugs, especially with aluminum heads, and I have never had a plug get stuck or cross threaded either. The plugs should come out at least for an inspection every 30k miles or so anyway, but with the modern high energy ignition systems, they can go much longer before they get bad enough to cause a misfire. I supposed you can also dump Seafoam or gumout down the intake and allow it to soak overnight, than soak in penetrating oil from both sides.