Stuck spark plugs
07-24-2017, 08:42 AM
#1
Stuck spark plugs
Hi Guys
I am in the process of changing my plugs on my 85 and most of the plugs feel like they won't break loose. I'm afraid of putting too much force for fear of breaking the plugs. So once again I am reaching out to the forum for any suggestions. Thank you again for the help
I am in the process of changing my plugs on my 85 and most of the plugs feel like they won't break loose. I'm afraid of putting too much force for fear of breaking the plugs. So once again I am reaching out to the forum for any suggestions. Thank you again for the help
07-24-2017, 09:34 AM
#2
Racer
With an 85 you have iron heads so that is a plus in this case. Things get dicey with stuck plugs in aluminum heads, i.e. pulling the threads in the head out with the plug. In your case patience and time are your friends. Get some penetrating fluid like PB blaster and shoot it at the base of the plugs. Let it work for a couple days while blasting it every couple hours or as often as you can. Should be good to go. A slight and I mean slight, tap of a hammer on your ratchet my be reduced to get the plug to break free.
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Jackzap (07-24-2017)
07-24-2017, 09:35 AM
#3
Le Mans Master
Member Since: Oct 2004
Location: South-central Missouri
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I suppose the first question (for me) is: are the heads iron or aluminum?
In the mean time, for the record, I use just a tiny bit of Never Seize on the tip of my finger, and swipe the threads just one time; top to bottom before reinstalling them. It ENDED my seized plug problems for oh...20+ years now I guess - that and using a torque wrench to put no more than 18-20# to avoid issues later. Just sayin....
In the mean time, for the record, I use just a tiny bit of Never Seize on the tip of my finger, and swipe the threads just one time; top to bottom before reinstalling them. It ENDED my seized plug problems for oh...20+ years now I guess - that and using a torque wrench to put no more than 18-20# to avoid issues later. Just sayin....
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Jackzap (07-24-2017)
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Jackzap (07-24-2017)
07-24-2017, 09:49 AM
#5
If you try to loosen the plugs squarely (keeping the socket straight), you shouldn't have an issue with the plug breaking. Usually if the plug does break, the hex is still in the bore, and you can still get a socket on it.
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Jackzap (07-24-2017)
07-24-2017, 09:50 AM
#6
Racer
Making the engine hot will in most cases will only make it worse, especially when threaded into aluminum because it cools very fast. I would try getting some penetrating spray and working that in the best you can and try to work the spark plug forward and backward.
What size ratchet are you using? You may need a longer length. They can take some good force to initially break them free. I usually use my 18" 3/8 flex head long handle ratchet.
What size ratchet are you using? You may need a longer length. They can take some good force to initially break them free. I usually use my 18" 3/8 flex head long handle ratchet.
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Jackzap (07-24-2017)
07-24-2017, 10:39 AM
#7
Race Director
If the plugs have been in there that long, they probably need to be changed anyway. They are cheap. If iron heads, just crank on them. If the insulator breaks, so be it. The car will probably run better with new plugs anyway.
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Jackzap (07-24-2017)
07-24-2017, 10:45 AM
#8
Safety Car
Here's a couple of things that might help. One of the best penetrants I've run into is a 50-50 mix of ATF and Acetone. It seems to get into places even thing like PB Blaster etc don't.
Something else that works at times is paraffin. Same stuff used in home caning. Especially if you can get the plug loose a little, with the engine warm to hot, loosen the plug a little and try to get the paraffin into the area between the plug and head. With a little luck, it will melt and run down the threads adding a little slickness between the plug and head, easing loosening up the plugs later on (once cooled).
Good luck.
Something else that works at times is paraffin. Same stuff used in home caning. Especially if you can get the plug loose a little, with the engine warm to hot, loosen the plug a little and try to get the paraffin into the area between the plug and head. With a little luck, it will melt and run down the threads adding a little slickness between the plug and head, easing loosening up the plugs later on (once cooled).
Good luck.
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Jackzap (07-24-2017)
07-24-2017, 11:48 AM
#9
Le Mans Master
I agree. Turn it out
Last edited by Cruisinfanatic; 07-24-2017 at 11:54 AM.
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Jackzap (07-24-2017)
07-24-2017, 01:24 PM
#10
Thank you all for the responses. I did forget to mention that they are cast iron heads. 60,000 miles and they were replaced by previous owner. I may be misunderstanding when I hear about plugs breaking. I've read about having to use special tools if the plug breaks. Is it just the porcelain part that breaks if that should happen or is it also possible that the hex portion can break off also as to where you would not be able to get a socket on it. Just trying to take all precautions so I don't get myself into trouble.
07-24-2017, 01:40 PM
#11
Team Owner
If you feel bad enough, take the manifolds out and get an air impact wrench on it. I wouldn't set it too high. Just enough that the hammering gets something loose.
If you succeed, don't get yourself some super expensive plug. You aren't a race car and you can spend a little less. Get a decent plug but not something that lasts forever or so the advertising says. I have NGK plugs that are not iridium or platinum. Every year, they come out and get tossed. New plugs have anti-seize on them so life is good. I get to inspect the plugs for oil fouling since they are out. Rich and lean running is kinda difficult with EFI since it changes the mixture.
If you succeed, don't get yourself some super expensive plug. You aren't a race car and you can spend a little less. Get a decent plug but not something that lasts forever or so the advertising says. I have NGK plugs that are not iridium or platinum. Every year, they come out and get tossed. New plugs have anti-seize on them so life is good. I get to inspect the plugs for oil fouling since they are out. Rich and lean running is kinda difficult with EFI since it changes the mixture.
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Jackzap (07-24-2017)
07-24-2017, 02:11 PM
#12
Melting Slicks
Member Since: Nov 2013
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Thank you all for the responses. I did forget to mention that they are cast iron heads. 60,000 miles and they were replaced by previous owner. I may be misunderstanding when I hear about plugs breaking. I've read about having to use special tools if the plug breaks. Is it just the porcelain part that breaks if that should happen or is it also possible that the hex portion can break off also as to where you would not be able to get a socket on it. Just trying to take all precautions so I don't get myself into trouble.
Not something you usually encounter on a small block with Iron heads. If the porcelain cracks it's no big deal. The hex part of the plug and the threads is all metal and once piece. You can still remove it. Never heard of one just breaking off in the head on a small block.
Get the wrench on it straight and it should be fine..
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Jackzap (07-24-2017)
07-25-2017, 05:38 PM
#13
Burning Brakes
spark plug
Check one of the plugs you've taken out with the socket you're using. Make sure that the plug is tight and there's no wiggle on it. If so try a different socket. Rounding the plug trying to get it loose will make your day go from just OK to oh s**t really fast.
07-25-2017, 09:20 PM
#14
Safety Car
Totally different design than plugs for a sbc (thank goodness).
07-29-2017, 08:26 AM
#15
Most of you guys are defining a "broken plug" as the porcelain breaking. The OP is concerned about the metal shell fracturing below the hex. Tapered seat spark plugs (like the 85's iron heads use) CAN break off below the hex if the threads are rusted into the head. Usually above the threads, but below the taper that contacts the head to seal. The thinnest cross-section of the plug. It's rare, but it does happen, so the OP's concern is valid.
I work on boats and yachts. I've had to deal with plenty of rusted-solid spark plugs in the gas marine engines. I had one engine where all 8 broke off in the head. Fun times. Soak it with PB. Or the 50/50 mix. Try tightening the plug just a skoshe before loosening. If the shell does break, the porcelain should come out with the hex. All that will be left in the head is the threaded shell. A proper sized easy-out should work on the shell (be sure the piston is down before you pound the easy-out into the shell) , then chase the threads. Use anti-seize for the new plugs. Again, just a skoshe, and don'[t get any on the taper seat or the plug will loosen over time.
Be patient, and you'll get them out. Even if one or more breaks, it won't be the end of the world. All except #8 are fairly straight-in to get to on an 85.
I work on boats and yachts. I've had to deal with plenty of rusted-solid spark plugs in the gas marine engines. I had one engine where all 8 broke off in the head. Fun times. Soak it with PB. Or the 50/50 mix. Try tightening the plug just a skoshe before loosening. If the shell does break, the porcelain should come out with the hex. All that will be left in the head is the threaded shell. A proper sized easy-out should work on the shell (be sure the piston is down before you pound the easy-out into the shell) , then chase the threads. Use anti-seize for the new plugs. Again, just a skoshe, and don'[t get any on the taper seat or the plug will loosen over time.
Be patient, and you'll get them out. Even if one or more breaks, it won't be the end of the world. All except #8 are fairly straight-in to get to on an 85.
Thank you again
07-29-2017, 08:34 AM
#16
Le Mans Master
Don't think it matters much. Any parts store has it right on the counter
07-29-2017, 09:06 AM
#17
Le Mans Master
I put antiseize on every plug I put into any engine..No need to put alot on, just fill the threads. Why not, what is it going to hurt... Better to be safe then sorry...WW
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Last edited by WW7; 07-29-2017 at 09:08 AM.
07-29-2017, 11:31 AM
#18
Le Mans Master
07-29-2017, 11:54 AM
#19
Team Owner
07-29-2017, 12:06 PM
#20
Drifting
