2002 mondeo spark plug destroyed. help!!

Question

i tried to start my 2002 1.8 mondeo zetec this morning, but it started to rattle, and knock as if i had pebbles inside my engine. i immediately turned the engine off and upon investigation found one of my spark plugs was destoyed. It was difficult to remove and the ceramic part has been smashed up into the plug itself. the other 3 plugs are intact and fine. could this be the timing chain that has snapped or something else completely? any suggestions greatly appreciated

Answer 1

As above, it won't have anything to do with the timing belt - remove the plug, and if the bottom part that sits within the cylinder head isn't completely intact, then you need to attempt to remove all of the pieces before restarting the engine. As above, a magnetised pickup tool is your best bet for any metal shrapnel, the ceramic bits aren't too vital to remove, but you should still try - perhaps blow them out with a high pressure air line.

Answer 2

It might be the plug has broken and those bits are causing the trouble, but it could be that you have dropped a valve or a bit of a valve has broken off and that broke the plug.  I would take all the plugs out and turn it over by hand with your finger over each plug hole.  See if there is compression in the cylinder in question.  If there is, then the major bits are probably OK.  The trouble is that if any ceramic from the plug has dropped into the bore, it wil cause bad scores fairly quickly.  I suspect you need to get the head off to clean out such sharp things properly.  If there is no compression or poor compression in that cylinder then it could be serious if the thing that got squashed in between the piston and plug knocked into the top of the piston.  

Good luck, but I think the head has to come off minimum, maybe new piston/valve etc.

If the cambelt was the cause, I woudl expect all the cyclinders to be affected as overlap will be the same in all of them.

Answer 3

If it was the timing belt it wouldn't have started the second time, it may be a defective plug, get what you can out of the cylinder with a magnet, and the rest with sticky stuff on a flex rod, what you use is up to you, just make sure it won't come off in the cylinder. then replace the plug. ( I would turn it over with the plug out first).