Was just wondering what DIY members here do when changing their spark plugs - do you apply any anti-seize grease/compound? Are we meant to? Reason I ask is I've been doing some research and came across the following advice which basically says don't use anti-seize for spark plugs going into Aluminium heads:


Anti-Seize should be used to retard the effects of galvanic corrosion which is the ionic interaction between two dissimilar metals. However, if the engine has aluminum heads copper anti-seize should not be used.

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Here's what Autolite says about using anti-seize (snicked off the net somewhere):

We do not recommend the use of any anti seize products for installing spark plugs. Anti seize compounds are typically composed of metallic,
electrically conductive ingredients. If anti seize compounds come in
contact with the core nose of the plugs, it can lead to a misfire condition.
Anti seize compounds can also have a torque multiplying effect when
installing plugs. This can lead to thread distortion and thread galling
resulting in cylinder head damage. Autolite spark plugs are nickel plated
to resist the effects of corrosion and seizing. However, plug seizure is
aggravated further when steel plugs are installed into aluminum cylinder
heads for a long period of time.

Here's what AC/Delco says:

Do not use any type of anti-seize compound on spark plug threads. Doing this will decrease the amount of friction between the threads. The result of the lowered friction is that when the spark plug is torqued to the proper specification, the spark plug is turned too far into the cylinder head. This increases the likelihood of pulling or stripping the threads in the cylinder head. Over-tightening of a spark plug can cause stretching of the spark plug shell and could allow blowby to pass through the gasket seal between the shell and insulator. Over-tightening also results in extremely difficult removal.


I'm about to put in the new plugs I bought a while ago - front 3 that is - and would like to know what seems to have worked best for people here.

Cheers,
Aj

Just dont over tighten them. You could torque them down, but generally its a quarter turn past firm... or something like that - 9 to 14 ftlbs. Repetitive over tightening stresses the threads, and heli-coiling heads is expensive work.

As for anti-seize on spark plugs - I've never heard of it being done. I've certainly never done it, or, had it recommended that I use it when installing spark plugs.

I use the stuff and so far so good no issues.

Never had to use it except as supplied with an O2 sensor. Never had it recommended nor seen any mechanic use it or any evidence of it being used on any of my plugs.

We have copper antiseize (high temp) and nickel anti seize (regular) at work, and ive heard that copper and aluminium together turns the aluminium into powder. If you were going to use any, nickel and only the tinyest bit is probably the safest way. Have you ever had much trouble removing spark plugs? Maybe just a longer handled wrench would be less trouble.

Do not use unless the threads in the head are tight, and even then, a bit of engine oil smeared onto the plug thread is fine. There should be no need for anti-seize if you replace your plugs regularly enough.

Given the rears are in there for 100k I would not call that regular.....

I use it if the threads are tight on the fronts and always on the rears, have done for years and will do for many more. Is a matter of being sensible and not doping it onto the plug, just a thin smear on the thread is all that is needed

As for autolite plugs, would not use them in a brush cutter so what ever they state I would take with a grain of salt

Personal preference, application and personal experience probably determine what to use/do. I've seen and replaced spark plugs on toyota v6's that have done well over 300,000kms (which are at 150K intervals) and have never had a stuck or seized plug. The same with commodore alloytec engines (120K intervals). On the other hand we all know that the current falcon v8's are nearly all seizing plugs into the heads even before first interval, and require ALOT of work to rectify.

Thanks guys for the replies. Replacing the front 3 tomorrow morning while she's still cold. General consensus seems to be that anti-seize is not required so that's what I'll go with. The service manual doesn't mention anti-seize either; Under "SPARK PLUG CHECK AND CLEANING" (section 16 ENGINE ELECTRICAL – Ignition System) simply says:



3. Remove the spark plugs.
4. Check for burned out electrode or damaged insulator.
Check for even burning.
5. Remove carbon deposits with a plug cleaner. Remove
sand from plug screw with compressed air.
6. Use a plug gap gauge to check that the plug gap is
within the standard value range. Replace the spark plug
if the limit is exceeded.
Standard value: 1.0–1.1 mm
7. Clean the engine plug holes.
8. Install the spark plugs.

Yes experience does count and remember I ahve been working on cars for over 20 years lol.

Magna's I have had many many of these where the rear bank plugs have been a real trial to remove, takend on a few occasions a couple hours of work to get them out, others I have taken out in seconds

have had a few where fronts have been similar but less often due to the fact that they are not in there as long

Yes experience does count and remember I ahve been working on cars for over 20 years lol.

Magna's I have had many many of these where the rear bank plugs have been a real trial to remove, takend on a few occasions a couple hours of work to get them out, others I have taken out in seconds

have had a few where fronts have been similar but less often due to the fact that they are not in there as long

I'm no mechanic but I have to agree with Mal, for the price of a sachet it's good insurance, you can get them at Supercheap for a few $$ and one sachet will last for ages, I also use dielectric grease on the boots so they don't break.

I've always used Penrite CopperEze on my plugs and have done for over 20 years, never had any problems with seized plugs.

Had to go out and buy a longer extension for my socket set as I had no idea the plugs live so deep down those plug wells. I was surprised at how little force I had to use to undo them, it honestly felt like they hadn't been tightened properly.

One thing that worries me though is this: there was a fair bit (about a teaspoon I'd say) of engine oil pooled up in the plug well and each plug I withdrew (OP here and I'm talking about the front bank) came out with oil on its threads. I guess that means my rocker cover gasket is leaking but it also means that the new plugs I installed must now have engine oil on their threads too (via oil that was in the plug well and which would have seeped down onto the threads of the plug hole). Should I be worried?

Not at all, but do get those seals replaced. They'll damage your high tension leads by swelling the rubber insulation.

Had to go out and buy a longer extension for my socket set as I had no idea the plugs live so deep down those plug wells. I was surprised at how little force I had to use to undo them, it honestly felt like they hadn't been tightened properly.

One thing that worries me though is this: there was a fair bit (about a teaspoon I'd say) of engine oil pooled up in the plug well and each plug I withdrew (OP here and I'm talking about the front bank) came out with oil on its threads. I guess that means my rocker cover gasket is leaking but it also means that the new plugs I installed must now have engine oil on their threads too (via oil that was in the plug well and which would have seeped down onto the threads of the plug hole). Should I be worried?

Mine were like that too, I'm fairly sure it was due to the spark plug seals leaking down and the oil making it's way into the threads, I initially thought valve stem seals but I've got no smoke, haven't check them since as this was the rear bank.

Yeah mine's not smoking either. Thanks for the replies. Must get those seals replaced.

Oil in the spark plug tubes & pooled on top of the spark plug is most often from a perished Tube Seal (the O-ring at the top of the spark plug tube, between the rocker cover and the spark plug tube). It's located under the rocker cover, so will need to be replaced when you next get the front/rear rocker cover gasket replaced.

Thanks mate. I take it nothing really bad will happen if I just leave it be for now till I eventually get round to replacing the rocker cover gasket?

Thanks mate. I take it nothing really bad will happen if I just leave it be for now till I eventually get round to replacing the rocker cover gasket?

Refer to my last post.

I've used antiseize on plugs in bikes, cars and industrial stuff like pumps and chainsaws for 30+ years. No problems at all. All my threads are lubricated with some form of grease, antiseize or loctite. Means they come apart as required and corect torquing to spec is simply achieved.

Steve

Refer to my last post.

Ah yes, sorry, I missed that. Thanks.