Seized Spark Plug

Author
Discussion

giblet

Original Poster:

8,932 posts

184 months

Wednesday 23rd October 2013
quotequote all
The trusty K11 decided to cut out on me the other day as I was reversing out of the driveway. Initially I assumed it was battery related so charged it up but it still wouldn't start. Then I remembered that the plugs hadn't been changed in a while. I managed to remove the first 3 plugs and replace them, they were all pretty fouled.

The fourth plug however is proving to be a gigantic pain in the backside. I ended up snapping the arm from a recently purchased Draper spark plug wrench whilst trying to remove the plug. It seems to be seized on pretty well. Bought some PlugGas earlier and doused the plug with it, left it for 30 mins but its still not budging.

I'm trying not to be too heavy handed as I don't want to end up breaking the sodding plug but its not shifting at all. The car started fine with 3 fresh plugs but then cut out. Any ideas or suggestions?

steveo3002

10,664 posts

181 months

Wednesday 23rd October 2013
quotequote all
run the engine up till its hot then more plus gas and leave /maybe repeat

what sort of length handle did you snap off trying it?

giblet

Original Poster:

8,932 posts

184 months

Thursday 24th October 2013
quotequote all
The car no longer starts so I can't try heating up the engine. I snapped the arm off one of these. Towed it down to a local garage to see if they can remove the plug. It's rather annoying as I was planning on changing the plugs in a few weeks, should have done it earlier!

DocArbathnot

27,533 posts

190 months

Thursday 24th October 2013
quotequote all
You did the right thing.

muckymotor

2,323 posts

228 months

Sunday 27th October 2013
quotequote all
Did the garage get it out?

I once had a similar thing with a seized wheel bolt, soaked it in plus gas and even broke a wheel brace so I gave up and drove to the local tyre bay. By the time I arrived I think the plus gas had had more time to work and the fitter removed it without even breaking sweat. He looked at me as if I was stupid hehe

giblet

Original Poster:

8,932 posts

184 months

Sunday 27th October 2013
quotequote all
Yup, It spent a night soaking in plusgas before it got towed to the garage. I'm guessing that helped them remove it! Turned out to be a dodgy crankshaft sensor that was causing the cutting out. Plus were overdue a change too so its all sorted now.

lescombes

968 posts

217 months

Tuesday 29th October 2013
quotequote all
A little smear of Copper Grease on the threads helps plugs not to seize in head, same applies to glowplugs.... *wink*

trickywoo

12,310 posts

237 months

Wednesday 30th October 2013
quotequote all
lescombes said:
A little smear of Copper Grease on the threads helps plugs not to seize in head, same applies to glowplugs.... *wink*
I'd not advise this but each to their own.

Plugs really shouldn't be too tight. Hand tight plus a 'nip' is fine.

Mojocvh

16,837 posts

269 months

Friday 1st November 2013
quotequote all
Lubrcate threads only when advised not off the cuff!

one eyed mick

1,189 posts

168 months

Friday 1st November 2013
quotequote all
Have used copper grease on plugs for years ,a very slight smear ,works and causes no probs ,correct torque figs if you are pedantic are better than guessing !

Jimmyarm

1,962 posts

185 months

Friday 1st November 2013
quotequote all
Mojocvh said:
Lubrcate threads only when advised not off the cuff!
A wise man once said "Lubrication is the key to success"

He also said "treat your motor like your missus"

I agree with Mick on this, I always lightly lubricate plugs and have never had an issue.

giblet

Original Poster:

8,932 posts

184 months

Friday 1st November 2013
quotequote all
I've always gone with the hand tight plus a nip approach which has never caused me issues. I think the plugs were last changed by a garage who must have over tightened them. Turned out it wasn't the plugs that was causing the issue, so much for legendary K11 reliability

bearman68

4,795 posts

139 months

Sunday 3rd November 2013
quotequote all
Why not torque the plugs? - can't be wrong then.
Incidentaly I gather even new plugs should be gapped, as the new plugs are not always the correct gap for the engine.

Mojocvh

16,837 posts

269 months

Saturday 9th November 2013
quotequote all
Jimmyarm said:
Mojocvh said:
Lubrcate threads only when advised not off the cuff!
A wise man once said "Lubrication is the key to success"

He also said "treat your motor like your missus"

I agree with Mick on this, I always lightly lubricate plugs and have never had an issue.
http://ngkntk.co.uk/index.php/technical-centre/spark-plugs/tightening-torque/

.........NGK does not recommend the application of lubricant to spark plug threads as the resultant reduction of frictional forces at the thread faces will render the torque charts inaccurate and over tightening could occur.......

http://www.ngksparkplugs.com/techinfo/spark_plugs/...

....Torque is one of the most critical aspects of spark plug installation. Torque directly affects the spark plugs' ability to transfer heat out of the combustion chamber. A spark plug that is under-torqued will not be fully seated on the cylinder head, hence heat transfer will be slowed. This will tend to elevate combustion chamber temperatures to unsafe levels, and pre-ignition and detonation will usually follow. Serious engine damage is not far behind.

An over-torqued spark plug can suffer from severe stress to the Metal Shell which in turn can distort the spark plug's inner gas seals or even cause a hairline fracture to the spark plug's insulator...in either case, heat transfer can again be slowed and the above mentioned conditions can occur....

I do not fit spark plugs for a living.

http://www.ith.de/index.php/cmd/produkte.werkzeuge...

wink

andyiley

9,976 posts

159 months

Sunday 10th November 2013
quotequote all
I hate to disagree, but we do not torque spark plugs.

If you read the instructions on spark plug installation in any manual they say something like:

If they have a compression washer (which every one I have ever installed has had) then do them up finger tight plus 1/4 turn.

Now that is not a torque setting as far as I am aware.

Yes that does equate to a torque reading, which when greased will be less, but if you do as per the instructions you CANNOT over torque a spark plug.

I have always used a very light smear of copperslip (or similar) and have never had one even get close to siezing.

magpie215

4,594 posts

196 months

Sunday 10th November 2013
quotequote all
giblet said:
so much for legendary K11 reliability
Guess you have the later k11 with coil over plug ......unfortunately thats when they went downhill....earlier engine with dissy cap and leads is reliable

Auntieroll

543 posts

191 months

Sunday 10th November 2013
quotequote all
A few years ago Champion used to sell a tool specifically for torgueing up spark plugs, mine sits in my toolbox and is (increasingly rarely) still used for taper seat plugs which can be absolute B******s to remove. Anyone ever tried to get a set of overtightened Motorcraft (or any other come to that)plugs out of a Pinto?

I was taught never to lubricate plug threads as the grease holds grit in it which could fall into the cylinder and is AFAIK not a recognised way of extending the life of an engine.
Just blow round the plugs with an air line before removal to minimise the possibility of the above occurring.

andyiley

9,976 posts

159 months

Sunday 10th November 2013
quotequote all
Auntieroll said:
A few years ago Champion used to sell a tool specifically for torgueing up spark plugs, mine sits in my toolbox and is (increasingly rarely) still used for taper seat plugs which can be absolute B******s to remove. Anyone ever tried to get a set of overtightened Motorcraft (or any other come to that)plugs out of a Pinto?

I was taught never to lubricate plug threads as the grease holds grit in it which could fall into the cylinder and is AFAIK not a recognised way of extending the life of an engine.
Just blow round the plugs with an air line before removal to minimise the possibility of the above occurring.
As you may have realised from my post, I have never come across tapered plugs, and I am sure they are a right b@stard for getting seized/overdone more easily.

Yes you are right about the grease possibly getting bits stuck in it, but that is also why it is a good idea, because it does get stuck in it, as in does not fall into the plug hole.

Apart from that I am talking the tiniest smear, that is almost imperceptible, so not an issue anyway.

You are of course correct on your final point, you should ALWAYS blow the plug hole out first to remove any grit etc. before removing the plug.

one eyed mick

1,189 posts

168 months

Sunday 10th November 2013
quotequote all
andyiley said:
As you may have realised from my post, I have never come across tapered plugs, and I am sure they are a right b@stard for getting seized/overdone more easily.

Yes you are right about the grease possibly getting bits stuck in it, but that is also why it is a good idea, because it does get stuck in it, as in does not fall into the plug hole.

Apart from that I am talking the tiniest smear, that is almost imperceptible, so not an issue anyway.

You are of course correct on your final point, you should ALWAYS blow the plug hole out first to remove any grit etc. before removing the plug.
They are no worse than any other plug as long as a smear of copper lube mainly on the seat and they have not been putin by a gorrila