Two posts on this thread confuse me no end.
The copper grease reply makes little sense, yes some copper grease contains a very small amount of lead, it is meant to be put on the threads very sparingly and it is such a small amount of lead it will not damage your cat or lambda sensor. Although unleaded petrol has no added lead, there is traces of lead in the fuel by nature.

The other post that I feel is wrong is the remark that a plug that has not had the sealing washer properly crushed can cause a piston to be holed due to this, I'd like to read any evidence to prove this as I personally believe it is wrong. The tip of the plug it in the combustion space and the plug body cooled via the thread that is screwed into the head, the number of turns a plug needs till there is contact to the sealing washer means that there will be minimal leakage of combustion gasses through the thread, copper grease on them will reduce this even more, in all my years I have yet to hear of this phenomenon.

Copper grease comes in many many different formulations.

Almost all of them used to contain large quantities of lead.

Large containers of copper grease tend to last a long time because it is often used sparingly.
So there could be plenty of part used containers with lead still around.

I have a tin with a huge warning on it not to eat, drink or smoke while using and to thoroughly wash hands after use because of the lead content.

If any additional lead gets into combustion chamber it will pass through to the exhaust system and form a layer on the lambda sensor causing it to stop working and possibly do the same to the catalytic converter.

Some people use a lot of copper grease on their spark plugs rather than a little.

There are anti seize greases pastes that contain no lead and are therefore safe to use on plugs/ lambda sensors etc.

It is far cheaper to make sure the grease contains no lead than replace the lambda sensor and cat if it's also contaminated.

The chances are if the original poster bought new copper grease it's fine but may want to make sure. If it's an old tin from anywhere find out for sure.

It's absolutely fine for original poster to ask why lead may be a problem in fact it's a great question.

Rtv gasket maker is available silicon free so that it's safe to use on inlet manifolds because silicon causes lambda sensors and catalytic converters to stop working in same way as lead.

I thought the point of forum was to share information and try to help others.

Hi.
Well I've been using Copper grease on plugs for years. Before I took ill my annual mileage was 40,000 plus and TBH never had any issues with Lambda sensors or Cats.
My tin of Copper ease has no such warning of lead. This PDF from Copaslip has no reference to PB (Lead) in its formula. http://www.lloyd-jones.com/Styles/LAJB/Documents/MSDS%20-%20COP500.PDF

Lead/copper grease is available but at a price and not generally available to the public, it's mostly used in marine applications, if anyone has a old tin of lead/copper grease it has to be either for marine or is really old.
A google search for lead in copper grease was fruitless with the exception of marine use.

Silicon RTV should never be used on exhausts or exhaust manifolds http://www.autoserviceprofessional.com/article/93529/Catalytic-converter-diagnosis?Page=2
Have never heard of issues on the inlet side....... i would be happy to be corrected though.
I do agree that the forum is to help others and share info, but the info shared needs to be correct, if in doubt check and then post. I bet that many here would be unaware of the PB in copper grease as the mix has not been generally on sale for a very long time.

murphyv310 said:

Two posts on this thread confuse me no end.

The other post that I feel is wrong is the remark that a plug that has not had the sealing washer properly crushed can cause a piston to be holed due to this, I'd like to read any evidence to prove this as I personally believe it is wrong. The tip of the plug it in the combustion space and the plug body cooled via the thread that is screwed into the head, the number of turns a plug needs till there is contact to the sealing washer means that there will be minimal leakage of combustion gasses through the thread, copper grease on them will reduce this even more, in all my years I have yet to hear of this phenomenon.

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Jut because you've not had personal experience of something, does not make it untrue. This is why many people contribute to this forum, to gain a wider experience. Most on here try to be helpful and positive. YOU do not have any evidence that what I said is untrue, only your own opinion. I do have personal experience of this, from a previous job, working in the warranty department of a major parts supplier. A Daihatsu 1.0 3cyl engine suffered a holed piston. The melted plug had an uncrushed washer. The other two plugs were properly fitted and showed no signs of distress. Discussion with our plug supplier brought other examples they had experienced over several years.

The plug heat range is created by changing the shape of the insulator tip within the body of the plug. The NGK picture attached shows an example of this. The seating face, of which the washer is a part, is an important part of the heat path, and if it is unable to pass the correct heat, it can cause damage.

Your deriding of my warning is irresponsible. I warned that the plug should be properly fitted. This was nicely added to by jackwhoo, rightly adding that a reused plug should be fitted with a torque wrench. You seem to suggest that it does not matter if it isn't. Really? We'll look to you to recompense any subsequent failures then, shall we?

portland_bill said:

Jut because you've not had personal experience of something, does not make it untrue. This is why many people contribute to this forum, to gain a wider experience. Most on here try to be helpful and positive. YOU do not have any evidence that what I said is untrue, only your own opinion. I do have personal experience of this, from a previous job, working in the warranty department of a major parts supplier. A Daihatsu 1.0 3cyl engine suffered a holed piston. The melted plug had an uncrushed washer. The other two plugs were properly fitted and showed no signs of distress. Discussion with our plug supplier brought other examples they had experienced over several years.

The plug heat range is created by changing the shape of the insulator tip within the body of the plug. The NGK picture attached shows an example of this. The seating face, of which the washer is a part, is an important part of the heat path, and if it is unable to pass the correct heat, it can cause damage.

Your deriding of my warning is irresponsible. I warned that the plug should be properly fitted. This was nicely added to by jackwhoo, rightly adding that a reused plug should be fitted with a torque wrench. You seem to suggest that it does not matter if it isn't. Really? We'll look to you to recompense any subsequent failures then, shall we?

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Having also done many years as a secondary job in the motor trade and as back up for the Skoda rally team in the mid seventies I certainly don't come here as an idiot. While I accept and if you read back through my post I'm fully aware of plug cooling, the sealing washer though is only part of the plugs cooling, the surface area of the washer is considerably less than the area of of its threaded part, in fact the thread has a larger area than if the plug was unthreaded.
Like I have said in all the years of repairing engines, tuning, and working in garages etcetera I've not come across this. Ok you have but all I ask is a picture of the plug.............I don't think that is unfair unlike you being derogatory to me.

Also where did I say that the plug should be other that fitted correctly? I'm sure the advice should be not to overtighten the plug and fit to the manufacturers recommendations.
See my advice in Post 4 please

There is no doubt in my post.
The information posted about lead in copper type anti sieze is correct and checked before posting.

There is no point in repeating what i have already posted.

If you have inherited a tin of old anti seize or been given an old tin, by a kindly aged person clearing out their shed. you would be wise to source a new tube for your spark plugs. Use the old stuff elsewhere, don't eat it..... It may contain lead.

It's easier to avoid an expensive problem with lambda sensor and catalytic converter than fix those problems.

If anyone is interested in O2 sensor safe instant gasket they can use their time and look it up.

I thought point of forum was to be open minded, share information and help others , not find other people's posts try to pick holes.

Hi.
Who is picking holes? The lead in copper grease that you buy over the counter is long gone. I also agree that old tins really need to be binned. Lead is actually an excellent lubricant but rightly so if an old tin has a high lead content then keep it away from plug threads. My tin is near enough 10 years old and it says no lead. I'd most likely only use a lead/copper mix on brakes and other items away from the engine and not even on pre cat exhaust fixings.
So lets live in peace, there is nothing wrong with differing opinions..... that's how we learn.

No one on this thread has said there is lead in newly produced containers of anti seize, at any point.

jackwhoo said:

No one on this thread has said there is lead in newly produced containers of anti seize, at any point.

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Absolutely. I agree no one has.
At the end of the day the op has a result and that is excellent news