Technical What’s this on my spark plug?

[Mefster]

Just finished servicing our 121k 4x4 TwinAir, as no service history ()

Oil, filters and plugs done. Everything pretty clean so hopefully it’s been looked after.

Plugs were a bit of a struggle… finally manage after some penetrating oil applied. One of the plugs had a little rubber collar around the end. Nothing appeared to have detached from the coil packs. Reassembled and running fine.

I’m guessing it’s a rubber insert from a previous plug socket. Thought I’d better check it’s not a critical component unique to the TA engine!

 

[bugsymike]

Just finished servicing our 121k 4x4 TwinAir, as no service history ()

Oil, filters and plugs done. Everything pretty clean so hopefully it’s been looked after.

Plugs were a bit of a struggle… finally manage after some penetrating oil applied. One of the plugs had a little rubber collar around the end. Nothing appeared to have detached from the coil packs. Reassembled and running fine.

I’m guessing it’s a rubber insert from a previous plug socket. Thought I’d better check it’s not a critical component unique to the TA engine!

Yes looks like the rubber insert on some plug sockets to hold the plug when fitting.

 

[TTR]

Eh up,

Yup some idiot left a collar on ,

Just ensure you put a smear of coppervease on the threads and the correct torque settings ( think it’s circa 15nm ) someone will correct me .

Iridium plugs are best in the TA in my opinion

 

[Mefster]

Eh up,

Yup some idiot left a collar on ,

Just ensure you put a smear of coppervease on the threads and the correct torque settings ( think it’s circa 15nm ) someone will correct me .

Iridium plugs are best in the TA in my opinion

Thanks for that everyone. I’ve just nipped the plugs up to start- my plug wrench was at full extension with a t-handle- I’ve ordered a longer magnetic 3/8” socket so I can properly torque them.
On the subject of antiseaze: I’d read that modern plugs are designed not to have it applied- what is the consensus? (I’m also bearing in mind it was a struggle to remove the old plugs!)

 

[TTR]

Eh up

In my opinion- Bo88ocks ,

Just get a smear on and ignore the advice on modern plugs, just a sliver on the threads works a treat honest

I’ve done it since I had the TA and torque up to correct Nm

Make’s changing a doddle and no risk of snapped plugs

But everyone has their own opinions

 

[Peter Pick-Up]

Thanks for that everyone. I’ve just nipped the plugs up to start- my plug wrench was at full extension with a t-handle- I’ve ordered a longer magnetic 3/8” socket so I can properly torque them.
On the subject of antiseaze: I’d read that modern plugs are designed not to have it applied- what is the consensus? (I’m also bearing in mind it was a struggle to remove the old plugs!)

Using anti seize grease on the plug treads makes it impossible to get the correct torque, so don't use anything on them.
With grease on the plugs it's even possible to over tighten it and crack the head, or ruin the tread....!!

 

[bugsymike]

Using anti seize grease on the plug treads makes it impossible to get the correct torque, so don't use anything on them.
With grease on the plugs it's even possible to over tighten it and crack the head, or ruin the tread....!!

Apart from using a "thread chaser" on clogged or damaged threads , I have never felt the need to lubricate plug threads and just used experience when tightening plugs, no torque wrenches just over 50 years experience, they have never come loose and always were easy to change during servicing.

 

[KPat]

Apart from using a "thread chaser" on clogged or damaged threads , I have never felt the need to lubricate plug threads and just used experience when tightening plugs, no torque wrenches just over 50 years experience, they have never come loose and always were easy to change during servicing.

On Fords with cast iron cylinder heads that use taper seat spark plugs they are notorious for seizing. A bit of copper grease prevents it.

 

[bugsymike]

On Fords with cast iron cylinder heads that use taper seat spark plugs they are notorious for seizing. A bit of copper grease prevents it.

"Pinto" engines? Again no problem, all my customers were regulars and I only used NGK plugs, which in that engine were NGK AP6FS from memory.

 

[AnthonyH]

Just finished servicing our 121k 4x4 TwinAir, as no service history ()

Oil, filters and plugs done. Everything pretty clean so hopefully it’s been looked after.

Plugs were a bit of a struggle… finally manage after some penetrating oil applied. One of the plugs had a little rubber collar around the end. Nothing appeared to have detached from the coil packs. Reassembled and running fine.

I’m guessing it’s a rubber insert from a previous plug socket. Thought I’d better check it’s not a critical component unique to the TA engine!

Check its not come from your tool, mine has a rubber insert that is liable to fall out.

No grease.

 

[Pugglt Auld Jock]

Just finished servicing our 121k 4x4 TwinAir, as no service history ()

Oil, filters and plugs done. Everything pretty clean so hopefully it’s been looked after.

Plugs were a bit of a struggle… finally manage after some penetrating oil applied. One of the plugs had a little rubber collar around the end. Nothing appeared to have detached from the coil packs. Reassembled and running fine.

I’m guessing it’s a rubber insert from a previous plug socket. Thought I’d better check it’s not a critical component unique to the TA engine!

Eh up,

Yup some idiot left a collar on ,

Just ensure you put a smear of coppervease on the threads and the correct torque settings ( think it’s circa 15nm ) someone will correct me .

Iridium plugs are best in the TA in my opinion

Almost certainly the rubber collar from a spark plug socket. I have several sizes of plug socket and the rubber has fallen out of them all exept one and that one doesn't grip the plug any more. I bought two new magnetic plug sockets - 12mm and 14mm - and they are far superior to the type with the rubber retainer.

Whether to grease or not to grease spark plug threads? I started in this game in the 1960s when plugs were "bare metal" and heads were invariably cast iron. seized plug threads was a common problem especially as long reach plugs became the norm in many OHC heads. Our college instructor was a great fan for slapping a wee bit of Copa Slip grease on the threads and it was a common practice in several of the workshops I worked in. However, relatively recently spark plugs are electroplated with a "trivalent" coating on their threads which has two immediate effect - it reduces corrosion and also acts as a releasing agent when removing the plug as it "shears" when the plug is turned. It also makes a much better electrical connection between the plug and head and, because it has no lubricating properties, allows a "proper" torque tightening at installation. These electrocoated plugs are easy to identify as the threads have much of the appearance of a chromed finish. I now only use copa slip with older pattern plugs - which I still find on my old horticultural machines and the very occasional old motor cycle I get involved with. I actually use Alumslip if the head is an ally one. Having said all that, I don't actually torque plugs. Like Mike, I've been doing this for so many years I have the "mechanic's feel" for how tight to do them. In fact if it's a new crush washer type plug you can feel when the washer is crushing up and know that's when to stop tightening. Taper seat needs more "feel". I feel it needs to be taken into consideration also that a previous plug may have been installed with lubricant on it's threads which you won't be able to properly clean out of the threads in the head therefore compromising a proper application of torque and, finally, I'm also now fitting them without grease having become aware that heat transfer is a big issue on modern small turboed engines. There is an effect known as LSPI - Low Speed Pre Ignition - which can be exacerbated if the plug can't shed heat rapidly. Fitting the plug "dry" allows much better heat transfer.

This might interest you: https://ngksparkplugs.com/en/resources/5-things-you-should-know-about-spark-plugs

Here's some good stuff on LSPI, although you do have to filter out their attempts to sell you product: https://www.valvolineglobal.com/en-eur/what-is-lspi/

 

[AnthonyH]

I bought two new magnetic plug sockets - 12mm and 14mm - and they are far superior to the type with the rubber retainer.

I'm overdue buying one of these, so i'm going to go and look.

 

[Pugglt Auld Jock]

I'm overdue buying one of these, so i'm going to go and look.

Mine are just eBay purchases. Not comparable to Snap On etc. seem to get the job done though.

 

[AnthonyH]

I've just been looking for the spare spark plugs i know i have so i can measure them, but they're hiding...

My current tool seems to have a 17mm hex socket, so i guess i'm looking for one of those...