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Spark Plug Problem

sfitzy

By sfitzy,
in General Maintenance

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sfitzy Collaborator

sfitzy

Posted
Posted

I was changing my spark plugs last weekend and something strange happened.

As I was putting the new set in I got the the last plug no.6 closest to the firewall. Normally the Plug would rotate 10-11 times before I would need the torque wrench to tighten them up. But No. 6 only went around 4 times! Thinking nothing of this I went to put the coil packs back on only to find that now the no. 6 pack was sitting too high to do up the securing bolts!

So I went in again removed plug six and then had a look down it with a torch...

5-6 threads from the bottom was all this black crap. Probably carbon deposits. It was all jammed up in the thread, this didn't allow the plug to go down properly.

Has anyone got any easy solutions to this problem?

So far I have tried the following...

Cutting down a toothbrush (cleaning it up) and then using some carby cleaner to dissolve the carbon.... didn't work

Getting a cheap bottle brush and then using some carby cleaner to dissolve the carbon.... didn't work

Getting a old sprak plug cutting vertical grooves in it (like a tap/die) to collect the gunk... worked but took 6 hrs!

I would really like to know if anyone out there has a better, cheaper and easy solution than this, so I can clean the threads in the other five cylinders!

Thanks in advance

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JimX Grand Master

JimX

Posted
Posted

I've found carbon buildup to be really hard to remove. I think for a start a wire brush would be a lot better than a toothbrush, but even then I have worn out more than 2 wire brushes before I was able to clean carbon off something once. I'm not sure what sort of solvent disolves it, but finding the right type would be the first step I think. I know that carbie cleaner doesn't cut it, nor does turps or methelated spirits.

The best place to ask would be your local spare parts shop, they probably have some stuff designed specifically to disolve carbon.

Are you sure you need to clean the other 5 cylinders though? If they all went in all the way they should be fine.

wrxhoon Grand Master

wrxhoon

Posted
Posted

if the thread has carbon and u cant install the plugs all the way in u could use a tap on the thread but u have to make sure u clean all the shavings , dont drop any in the cil .

i never had the prob that bad so i couldnt screw the plugs in .

paydro Enthusiast

paydro

Posted
Posted

i had the same problem and got sick of it and though f**K it and ran the tap through and droped shavings down the cyl put everything back on and never had a problem as the shavings are only small and i didnt care as there was gona be a engine transplant going on soon any way but i never had a drama but it could all go wrong to i might have been lucky

JimX Grand Master

JimX

Posted
Posted

If you have really small metal shavings, chances are they will get burnt off when the engine fires.

What you can do if you do drop some small particles in there is put a compressed air line into the hole (not sealing it in) and switch it on. This will pressurise the cylinder with air and hopefully blow out whatever is in there. The same way that you can put a small scrunched up bit of paper into the neck of a bottle on its side and try blowing it out with your mouth. It'll come straight back out rather than blowing into the bottle. Of course, small particles may stick in the oil in the cylinder or fall down onto the rings, so it might not get everything out.

nick_w Explorer

nick_w

Posted
Posted

just a thought...

Maybe try cutting the grooves in the spark plug...as mentioned before, to act as a tap. But also break out all the guts of the spark plug aswell (or drill hole through it). This will allow you to feed an airline through the centre of the plug.

Using a box spanner (with the airline passing through it) you should be able to cut away the carbon while pressurising the cylinder at the same time to stop particles from getting in there.

Just a thought, ive never tried it or heard anyone that has.

wrxhoon Grand Master

wrxhoon

Posted
Posted

if u do that how are u going to get the shavings out that will be left stuck on the tread ? if i was going to use a tap i would put a rag inside the the cil and leave the last bit on the botton of the tread , when i finish the job blow compressed air in the hole so shavings will come out then carefully ( using a long nose or simmilar ) pull the rag out and hopefully no shavings drop in the cil .

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