UK Car Repair: vauxaull astra,mk3 1994, oil filler cap, exhaust stroke

Question
QUESTION: first notice power loss,which increased gradually,a banging noise,when accelerating,then would start but sounded to misfire.now turns but wont start at all.

ANSWER: Hi Nick ,form the info you provided it sounds like the Cambelt had jumped a couple of teeth and finally snapped. did it die while driving or just park up and it would not start afterwards? remove the oil filler cap and turn the engine over you will need an assistant to watch inside the oil filler neck for movement if there is no movement then the belt is broken if so there is a good chance that you would need to replace the valves too - let me know if this is the case -thanks Paul

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QUESTION: after much investigating discovered that cylinders 1 and 2 have no compression. the death of the car happend gradually over the space of about five hours first power loss increasing to not start at all,what could be the cause and the solution.many thanks for your input.Nick

Answer
Hello Nick, I would remove the cambelt cover and inspect the cambelt if 1 & 2 have no compression it could mean that the valves are stuck open(If cylinder 3 had just completed a power stroke then cylinder 4 would be on the compression stroke (if the firing order is 1342) and so 3 & 4 would have both valves closed whereas 2 would be on the induction stroke and the inlet valve would be open and and 1 would be on the exhaust stroke so the exhaust valve would be open)this would give compression in 3 & 4 and no compression in 1 & 2 the gradual dying is likely to be the belt stretching or missing before it finally snapped.when you turn the engine over does it sound 'faster than normal' is the best way i can describe it (no load on the crankshaft ,just spinning )? if the cambelt is fine then look at the camshaft for damage  -  let me know the results and we can go from there .good luck - Paul