Impact to remove spark plugs

Hall said:
Have you already tried with a hand tool and know they're "very tight" or you just presume they will be ? Got them soaking in penetrating fluid ? I think it's Eric from S Main Auto that uses an impact on some infamous Ford 3-valve (???) heads. Apparently it's almost normal for the plugs to break off in these but he's had better luck using an impact and they not break.
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I know they are tight- can't get 2 out no matter what I do. Curse, plead, pray etc. LOL . Afraid to ruin the head getting them out. Laugh at penetrating fluid
 
Tman220 said:
At that age and 41K it seems to be it's a seasonal, nice weather type of vehicle which doesn't see a lot of rain, or salt. What makes you think you will have any trouble removing these spark plugs in the first place? Unless it's a 3-valve ford modular??
I would personally give it a shot with a socket and elbow grease first. An impact will almost guarantee damage to the threads if they are indeed stuck, which I doubt given the mileage and age.
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True maybe they are not really really stuck but I'm reluctant to apply yet more force to find out. Try other things first. PPL here have alot of experience dealing with this stuff on a daily basis and like to help. So...ask them first
 
Please try to *tighten* them just a bit, just till they move, then loosen. I don't know why this works, but I've had success several times over the years doing this.
 
joekingcorvette said:
Blow out the plug area with compressed air. Soak them overnight with PB Blaster. Use a hand wrench and turn them about 1/8 of a turn to loosen the plugs. The tighten them back about 1/8 of a turn. Keep going back and forth and they should come right out without damage to the threads. I did this on my 05 Ford F-150 5.4 and didn't break any of them.
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Yes - Do as corvette suggested -
It works - I did this on a Mustang with their lovely 2piece plugs - - - - -
 
Dave9 said:
^ That's only if you get the engine too hot, then not for the reason stated in the video but rather that it softens the aluminum.

How the coefficient of expansion affects a hole in a piece of metal is universal, the hole will always expand. The head is clamped down, but don't you think that what it's bolted to, is hotter still and also expands? It has to be engineered to allow for that or else things break and/or fasteners loosen.

You can test this yourself, find a piece of cast aluminum (whatever), and put a hole in it just large enough to put a fastener through, then notice increased slop after heating it. If you heat the fastener to the same temp too, then it has to have a lower coefficient of expansion, like a spark plug's steel threads do vs aluminum.
Click to expand...
Cylinder bores also expand when the block heats up, super tight tolerance engines like F1 cars need to the block brought up to temperature first before they start the engine to make room for the pistons when they expand with increasing temperature.
If you try to start the engine cold, the pistons will expand too fast before the block will, and scuff on the cylinder walls.
 
IndyIan said:
Cylinder bores also expand when the block heats up, super tight tolerance engines like F1 cars need to the block brought up to temperature first before they start the engine to make room for the pistons when they expand with increasing temperature.
If you try to start the engine cold, the pistons will expand too fast before the block will, and scuff on the cylinder walls.
Click to expand...
Interesting, re F1 engines. Learned something. Makes sense, though, re pulling every last bit of power out of the given displacement... u want clearance of pistons in the block (or barrel) perfect at running temp.
 
Engine at operating temperature and a 3/8 impact is how I do the original design 5.4 3v spark plugs. That method hasn’t let me down yet.
 
Practically, if the sparkplug is not plumb, with the electrode down, how are you going to dispense any refrigerant liquid onto it, i.e. so that said liquid stays on the sparkplug, and does not migrate onto the aluminum head? Even with perfect-orientation plugs, which are often in deep wells, again, how to refrigerate the plug and not the head? Simply not practical. Good penetrating oil, time, 1/8th or 1/16th turn tightening, and then loosening, a few times... over an extended period of time... and then bringing engine to operating temp... that'd be the way I'd do it.

This pre-supposes you CAN do it over several days.
 
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