Spark Plug Removal

I put iridium plugs in my 4.0 Tacoma a bunch of miles back and thought it would be more than about time to change them. Don't recall if I used anti-seize or not, but when going after the first plug it took a good 20 minutes of back and forth twisting to get it out. When it finally did get out there were no signs of galling or warped threads. A new one with anti-seize went in nicely.

The question I have is, has anyone found it easier to take a stubborn plug out with a hot or warm engine compared to the cold engine I was working with? I know it may not be a good idea to expose the valves on a fully hot engine to cool air if you remove a plug so I will not try to take any out with a fully heated engine. I don't think that any sort of thread loosing spray would help in this case either because there is no rust involved and the threads are so tight it would be near impossible for it to get in there.

 

When I have that issue, I spray a penetrating oil like WD40 or Blaster alongside the plug and let it work its way into the threads and then work it back and forth until it loosens up. Maybe five or ten minutes and it's out. It seems to dissolve the carbon and hasn't failed me yet.

 

Nope, I would NOT take plugs out of a hot engine.
Aluminum is soft to began with.

Even worse is installing a plug in a warm/hot engine.

And I understand other will say it’s ok. I’ve been in that debate before, not going back there.
Anyone can do anything they want with their engine.

My advice is more of an opinion.
So do with it as you please.

 

Cold engine as aluminum gets softer the hotter it gets and it expands at a faster rate than steel.

 

A Toyota Master mechanic told me to work on a cold/cool engine, disconnect the battery, and remove all rings, watches, and bracelets from my fingers and wrists. I am sure there will be different opinions on this but use common sense and safety, safety, safety.

 

Thanks for the input, it was good enough for me. Cold engine only. Now for the patience to go slow, back and forth until they all come out.

 

I'd loosen each one a quarter of a turn, spray some WD-40 down the tube, go inside and chill for about 30 minutes then resume the operation.
I had to do this on my old Corolla a few years ago. Worked like a charm.

 

Kroil oil, liquid wrench or squirt a 50/50 mix of atf/acetone would do wonders versus a very weak lubricant like WD40 for any tasks that requires a penetrant.

 

Cold engine for sure. Overnight if you know it's a difficult one. I like to blow them off with an air blow gun first so I'm not washing dirt into the plug threads. Be ready with the correct socket extension ratchet combination, crack it loose, spray penetrant of your liking, then I like to use a T handle, my in and out technique is out til I feel tension, in most of the way, out til I feel tension again. If it feels like it's really stiff when it's almost out, spray it again, almost all the way in, then find the sweet spot to go repeatedly in and out. That'll work it in really good. If it still feels like it's gonna rip threads out it might be a good idea to put it back in until you have a spark plug tap and correct size helicoil kit. KD makes a good kit.

 

When changing the plugs on my Expedition with the aluminum head 5.4l that was known to randomly eject spark plugs, it was suggested that you slightly tighten the plug before trying to remove it. Worked well and didn't ruin the threads in the head. The same technique has worked when removing bush hog blade bolts. I couldn't break them loose with a 5ft cheater pipe, until I first tightened them. Sounds counter intuitive, but it works. Yeah, definitely change the plugs on a cold engine.

 

I consider the tacoma 4.0 a 3/10 on difficulty.

The 5.4 is a 9/10. It's a bastard even if they aren't breaking. I used to get it orange hot, shut it down, remove coils and spray penetrating fluid on the plugs. Then carefully remove them by manipulating them like you say.

 

I don't understand why everyone puts anti-seize on spark plugs in aluminum heads? I'm a young guy, but have been professionally working on cars for over 10 years now and I've only ever heard of putting anti-seize on plugs in iron heads. Spark plugs never come from factory on any Japanese vehicle with anything on the treads. Anti seize in the wrong conditions turns rock hard. Thats why you don't put anti-seize on slide pins of brake calipers.

Right? change my mind please.

 

I had the pleasure of working on new engines, aluminum head, which used plugs that had about a 1/4” worth of threads extended into the combustion chamber. Getting them out without damaging the threads was impossible. So what I did was at the first oil change, pulled every plug and put it back in with anti seize. The choice was either do that or plan on helicoil repairing in the future. Sometimes a plug tap would fix it good enough. Going back in with new plugs without anti seize would have been foolish. Now they come with plugs that have an unthreaded portion on the end. This isn’t an issue on the 4.0 but I still anti seize my plugs on everything.

 

No argument here, I just use what I have readily available and I've used other penetrating oils, even a silicone spray. All you're trying to do here is dissolve the carbon build-up on the threads.

 

Anti-seize helps prevent galvanic corrosion. And, you dont use use anti seize on most brake slide pins because it is not compatible with rubber/nitrile. You use high temp silicone in those situations.

 

You sure we’re talking about spark plugs here? I felt dirty reading this.

 

Although anti-seize is in fact designed for corrosion resistance, just note that zinc chromate or nickel coated spark plug threads eliminate the need for compound as it is a sacrificial coating that just crumbles off when popping them loose.

The use of anti-seize on these threads should be installed with a lower torque value than if installed out of the box dry.

Absolutely use anti-seize on black oxide coated spark plugs if you ever want to get them back out.

Each to there own - their circus, their monkeys.