Broken Spark Plug

[new2 7s]

I need some advise before I do more work then needed.

 

I own a crossflow powered Caterham 7, this morning I was cleaning and reinstalling my spark plugs when one of the plugs broke off at the threads leaving the threaded portion only and what is left of the porcelain stuck in the head and flush with the top of the spark plug hole.

Do I need to remove the head to get the remains of the plug removed or can I use a drill to remove the rest of the porcelain and an easy out to remove the threaded portion of the remains of the spark plug?

 

Thanks,

Scott

Los Angeles

[tnttim]

The best way to would be to remove the head.

 

If you try to drill the spark plug the shaving will most likely go onto the top of the piston. AND we all know having stuff floating around in the cylinder is not a good thing. The metal shavings wouldn't be as bad as the porceilain be cause they melt and get soft in the chamber and will eventually blow out (if they dont get stuck in the valves). But the ceramic will not melt and will scratch and chip anything they come in contact with.

 

If you punch out the rest of the ceramic and then use the easy out to remove the threaded ferrel then you still have to worry about the debrit in the cyl. . If you have the use of a BoroScope and one of those keyboard vacuumes with a little hose on it to suck out the chips then go for it. Because if you don't get them all you still have to remove the head anyway. But you need to make sure you get any that are a grain of sand or bigger.

 

My engine has eaten a few aluminium turbo blades and I have kept an eye on the cylinders with a scope and pressure tests and havent noticed anything to bad. But with the long tubes and the intercooler I am sure what reached the engine was grain of sand or dust size.

 

I would be more afraid of damaging the threads of the cyl. head than anything. If you do you are looking at exspensive repairs or have to replace the head.

 

So.... Simply, remove the heads it is the correct thing to do. And while your there give the pistons and head a good cleaning and you may notice a bit more performance.

 

 

 

Tim

[DeanG]

Pulling the head shouldn't be too bad but will be more expensive (i.e., gasket and possibly new head bolts). It allows a good check of the flatness of the head and block. If you choose to leave the head on make sure you turn over the engine so that the valves on the cylinder in question are closed.

 

Good luck.

[new2 7s]

Thanks for the input, I was able to remove the broken piece of spark plug with a flat head screw driver and my finger tips.... I dont think any of the porceline fell into the combustion chamber.... I fired up the motor after putting a new set of plug in and everything sounds okay.