seized spark plugs

a friend has a 54 pontiac with a bb v8 fitted.the 4 plugs on the passenger side are resisting reasonable efforts to remove them.heads are cast iron.whats the best way to get them out without stripping threads.thanx lads

 

The biggest fear I always have on stuck ones is that they will snap off, leaving the threaded portion in the head. Soaking them with something like PB Blaster or a 50/50 mix of trans fluid and acetone for a few days can help, and some heads have that "pocket" around the plug so fluid can puddle around the base of the plug, so that helps.

I have heard of heating the head around the plug with a torch, but not heating the plug, then removing it while the plug is still cool. Some people say they use those cans of compressed air that are made to clean computer keyboards to "chill" the plug, but I have never tried that one.

If it starts to move rock it back an forth both directions a little at a time until it comes out because there is usually some carbon on the bottom that will cause the plug to lock up in the threads. If you keep going one direction then the next it will break it loose easier.

Once you get it out you can buy a thread chaser at places like NAPA to retap clean thread in the head, then use antiseize on all the new plugs so you don't have that problem again.

Don

 

Hey, I use Anti-Seize on a lotta stuff, never have any more problems here in the east too...........! scrubba

 

Every time I remove plug's I use Anti-Seize. Same here no problem's.

 

I`ve had good luck with soaking them with a little brake fluid, then rocking them back and forth a bit until they come out. take your time.

 

Sounds to me that the engine is still in the car...I would try to remove them after getting the engine to operating temp.
Like Don, I would be concerned with breaking them if some gorilla used a big wrench to install them. They don't require alot of torque. And, yes, use a 'never-seize' type of lube on the new ones.
If they break then... Plan ahead.

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I've had stubborn ones I soaked with Marvel Mystery Oil for a few days and it did the trick. Jack the car up on that side a bit so it stays puddled around the plugs.

We used to use heat on marine engines, those always had stuck spark plugs. Even a small Berzomatic type torch gets them hot enough.

Bob

 

I'd love to see that big block in the engine bay...

I would bring the motor up to temp, and pb-blaster the plugs. Rock back and forth until they come loose.

 

THANX for the replies.i only became aware of the problem today following a visit to check on progress on my 38 chev.i sprayed the plugs with penetrating fluid before the car left for home.we plan on spraying it a few more times before trying to remove them again.

 

I use that stuff on almost everything

 

i think the plugs in it were fitted when it was imported from the us

 

The spark gasket seals maybe 500 PSI without leaking. With the plug tightened it is not possible for penetrating oil to get past the gasket to the threads.

 

I've seen some people with newer car have problems removing the plugs for the first time because now the car makers are saying they don't need changed for 50-100,000 miles. By that time the plugs have been in there for at least several years, if not more, and the factories aren't smart enough to use antiseize, so the gall in place.

If any of you have a new car and intend on keeping it for years you might want to pull the plugs out now and coat them to save yourself some grief later on.

Don

 

Surprisingly, it does. Been there, done that.

Don

 

That works great BEFORE they are installed but is useless getting them out. HRP

 

Lol.I got an older friend that says those sort of things"you shoulda done it like this"...

But yeah,pb blast that.I've used it on a bunch of stuff including seized engines and its never failed.
I hear heat works too.

 

also... never mix loctite with anti-seize...

 

Yeah. And never take a laxative and a sleeping pill at the SAME TIME.

Just curious: Is this a '70s engine with the smaller spark plugs and no plug gaskets (tapered seat)?

 

That's what happened to me with my 2000 chevy 1/2 ton 4X4. At 100.000 I changed the plug's and two of them scared me bad.Felt that anytime the
plug would brake off or strip the thread's.I was very lucky that day.LOL

 

Back the plug out till it stops, turn back in 1/2 turn and soak with penetrating oil (Kroil is the best) Wait 12 hours and repeat. The plug will back out a little further each day until it's free. Don't be in a hurry, work it out a little at a time letting the oil dissolve the carbon and rust.

 

If it works the plug wasn't tight.

 

Thanks for asking this. I had the same problem with two of my plugs. I just left them in because they were still working. Now, 2 years later, I know how to get them out. I didn't think penetrating fluid would work so I didn't even try it. (Duh.) Thanks for all the advice.

 

When i was a mechanic in the 70s we used graphite grease on the plugs,mostly alloy heads and that kept them free. It suprises me that penetrating can get past the seal on a plug, how the hell does it stay in the can !!!!!!!!!! JW

 

dont know that but i will try to find out tomorrow ,

 

Unless it is a Triton 5.4 or 6.8 ...... They change themselves.

 

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Almost every engine manual I've ever read says NOT to use neversieze on spark plugs. I've been doing it for at least 40 years, have no reason not to.

 

The concern with using any thread conpound on a spark plug is the possibility of losing ground...

.

 

I took a lesson from customer cars,...And agree that those 50,000 mile tune ups are not the best idea, especially with aluminum heads. The first thing to do, when buying an engine with aluminum heads is to remove the plugs and do the anti sieze thing, as well as not doing a gorilla dance , when re installing them. It can be a p.i.a. for sure,...but a lot better, than trying to install "Heli-Coil" inserts later.

4TTRUK