Hi

i recently discovered i had no compression on cylinder 2 of my mk2 2005 focus. I have just finished removing the head to investigate the problem. I have found a chunk missing out of one of the valves, but cannot see where the piece of valve has gone. Should this be of concern and warrant further investigation or could it have just sent it into the exhaust? Any suggestions would be much appreciated. Thanks.

1 hour ago, Oggy02 said:

warrant further investigation or could it have just sent it into the exhaust?

Ouch!

I once had a Triumph 2000 head that had a valve hole like that. It did not go very well with it!

Make sure you get that piston right down to BDC, and have a good look at the cylinder bore for scores.

Perhaps have a poke around in the inlet manifold, if it went while in over-run, there is a very faint possibility it could have got sucked back into the inlet, but highly improbable really.

Otherwise, I can not think of any problems. The bit may be lodged in the cat, but should not do any harm there. Good job it has no turbo!

 

Thanks for the info mate. The part of the cylinder i can see, seems ok for scores. As you say, i will need to wind it down to BDC to check properly. Will check the inlet aswell.

Thanks again for your help.

23 hours ago, Oggy02 said:

Any suggestions would be much appreciated

I did have another thought. Why did that valve fail? If it was an inherent defect, then all the exhaust valves were probably from the same material batch, are the same age, and have experienced almost identical lives.

I do not know what your plans are for this engine, but might it be worth investigating replacing all the exhaust valves?

(I am assuming the smaller valves are exhaust, as that is normal.)

Hi mate

sorry for late reply, did not get an alert to say id received one.

At some point in the past, which you might be able to see from the pic, someone tried to repair the hole for the spark plug. They must have drilled it at an angle and gone close to the valve seat. They also damaged the thread. Dont think that caused the damage, but going to replace the head and valves, etc

Thanks for the suggestion though.