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Technical What’s this on my spark plug?

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Technical What’s this on my spark plug?

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Mefster

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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!
 

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Mefster said:
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!
Click to expand...
Yes looks like the rubber insert on some plug sockets to hold the plug when fitting.:)
 
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

👍
 
TTR said:
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

👍
Click to expand...
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!)
 
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

👍
 
Mefster said:
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!)
Click to expand...
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....!!
 
Peter Pick-Up said:
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....!!
Click to expand...
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.:)
 
bugsymike said:
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.:)
Click to expand...
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.
 
Mefster said:
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!
Click to expand...
Check its not come from your tool, mine has a rubber insert that is liable to fall out.

No grease.
 
Mefster said:
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!
Click to expand...
TTR said:
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

👍
Click to expand...
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 said:
I found this one, seems its 16mm not 17mm, as you can't buy 17mm spark plug removal tools.

Click to expand...
I'll try to post a picture of the four sockets which currently reside in my top box.



PXL_20251019_152504965.jpg

The two on the left are the old ones which had rubber inserts and the ones on the right are the new magnetic ones, you can see the magnetic ring just inside the end. Also the two on the left are 12 point (bi hex) with the two the right being six point (single hex)

PXL_20251019_153353285.jpg

They are the only two sizes I commonly use. The larger are 21mm and the smaller 16mm. Although in fact the ancient two on the left are marked 7/16 whit on the larger, which is actually an American made tool, and the smaller is marked 10mm, just to confuse! These two hardly ever come out of my tool box these days.

These two sizes seem to do everything I work on except some strimmer and leaf blowers which use a smaller hex. Luckily one of the several other older plug tools I have happens to fit them.

This last picture lets you see the size markings

PXL_20251019_152634041.MP.jpg
 
Thanks for that, informative.

I haven't bought just yet in case i missed something, but i'm now certain its 16mm i need. Magnetic is the win. The only small issue i could have is that the one on Amazon is 3/8 inch square socket, i'd prefer 1/2 inch, but maybe i have to let that go because i also need a "thin wall" for these Puntos of mine. A thicker walled socket won't go into the spark plug recess.

Many of those on ebay are 12 point sockets, are yours? I seem to think they'd be bad, i like the 6 point one i'm thinking about.

I also wonder why so many on ebay come with a swivel head bar that is attached to the socket. That just seems to be giving the spark plug an opportunity to move and de-thread.
 
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Pugglt Auld Jock said:
I should have said in my last post that it's the 16mm that fits our Pandas.

Here's a pair which would be fine I'm sure: https://www.ebay.co.uk/itm/325779473734?_skw=magnetic+spark+plug+sockets&epid=8017023215&itmmeta=01K7YGETBNSX726SP5Z5JFTH5J&hash=item4bd9f84546:g:BDUAAOSwvj1k3380&itmprp=enc:AQAKAAAA4FkggFvd1GGDu0w3yXCmi1eyaAVALW5oj/pAelgRsliFUGD49gdFjAbI8AzMxjvUwZsRdErKANc8SYXdW/FfX+V2v9s4MWIF/IXzQuLcaEIpF/yW1bdvO4/RlcYx/vxVf7bfK6EkHYex4KuwN2reY5ZKhI2wqWVg3H+ja3eeDZB+eMEQVSIsOECohibu/YY1IG6c4cG+BVLotf2wOILfbaKIWY5tSEP3gwkpBtQUkkvZB1G3AkJBy59S/ARi3Ji6Y/aZRGB2Q+c8im/lpgHtCucKCWszWytcWZ8sRimvopMU|tkp:Bk9SR4Cmu9C_Zg

I've got some Neilsen sockets and they are good enough for serious DIY use. These two sizes are by far the most common.
Click to expand...

Blimey you dug them up on ebay quick lol. For the same price as the Amazon one i get both sizes, has to be good, and a good brand, so they're the win!

They're half inch too, excellent.
 
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AnthonyH said:
Thanks for that, informative.

I haven't bought just yet in case i missed something, but i'm now certain its 16mm i need. Magnetic is the win. The only small issue i could have is that the one on Amazon is 3/8 inch square socket, i'd prefer 1/2 inch, but maybe i have to let that go because i also need a "thin wall" for these Puntos of mine. A thicker walled socket won't go into the spark plug recess.

Many of those on ebay are 12 point sockets, are yours? I seem to think they'd be bad, i like the 6 point one i'm thinking about.
Click to expand...
I too prefer half inch as, being "old school" it's the size I tend to grab first and single hex every time too! The ones I bought fit the panda 1.2 and others without any issues.

Edit. Ebay is my default rather than Amazon. Daughter swears by Amazon though!
 
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