Spark Plug came out!
 

Arrrrrrrgh!

Driving this morning and the engine light came on, stopped and used the code reader and got ODB 303 for a misfire on cylinder 3.

Now I have no idea how this has happened but the plug has worked itself out and fired itself into the coil pack destroying everything!

http://forum.a8parts.co.uk/picture.p...&pictureid=795

Trouble is the thread in the head has been damaged so I cannot get a new spark plug back in!

How much of a headache is it to repair the thread?

Anyone know the thread size so I can buy a chaser ?

I think its M14x1.25. I think I have a tap that size in the workshop if you need it.

Its possible to have the head helicoiled if you can't recover the thread. I had a Polo done many years ago. The challenge would be getting the tool in there since it's recessed so far, but a decent engine shop should be able to figure it out.

I have ordered a thread chaser tool to see if I can use that.

Looking at it tonight its only the first thread part that's damaged and the rest seems ok. I suspect the plug worked its way out then combustion fired it out at great speed, damaging the last thread and smashing it into the coil!

Its still an almighty pain the arse though!

The difficulty will be in making sure no metal fragments drop into the bore and down the piston skirt.....

Agreed hence I have hovered it and used the magnet to clean it up.

Also firing it up with no plug in to blow everything out.

That's what I was thinking. I'd be worried that there might be some fragments down there already.

Might be possible to get a small endoscope/borescope down there to inspect it.

I use this one: http://www.amazon.co.uk/gp/product/B00KV669US
Works quite well, but I'm yet to try poking it down a spark plug hole.

Thats not so good! How long ago was the plug changed/tightened?

Plugs were changes about a year or so ago, checked all the others and they are all tight.

90% of the thread seems OK its just the first one or so hence why I have ordered a chaser to see if I can get it back in.

Standard Spark plug chaser did not work as it cannot even make a start into the top thread. Looks like the first thread is damaged but all others are good and true.

So after a major google session and a few threads on other car forums I have found a plan B!

Purchased one of these online and could be perfect!

http://www.uktools.com/images/sea/big/VS625.jpg

http://www.sealey.co.uk/PLPageBuilde...roductid=14856