What can cause total compression loss across all 4 cylinders without timing belt snapping and no nasty noises when it dies or trys to start?

Engine in question is a Zetec-S 1.7 VCT engine....


As I can't think of anything that would do it without the head or block them selfs blowing? and nor can anyone else explain it?

 

Snaped cam?

 

Rings? Spark plugs blown out?

 

First thing i would do is check the timing bud, pin in the crank and plate in cams, if timing is out then its possible the belt has jumped and you may have bent valves, if it was me though i would re-time the engine and stick a belt on it first and try it

 

borescope it and have a look

 

Rings to go on all four at the same time? Funny enough two of the spark plugs ceramic surround did blow the same time as engine cut out and two ht leads burnt out to.

 

I was thinking that as I checked timing belt its self and it was fine.

 

ive seen these with melted exhaust valves before