I've had problems before where the spray bars stopped working, and then ruined the cam shaft. Well I replaced the spray bars and it worked for months without a problem. Then the noise started again, so this time i've replaced the camshaft and then used the car for a couple of weeks and then it started again. I've removed the rocker cover gasket and it looks like the spray bars aren't working again. The real question is, the bolts that hold the spray bars down, one of them has ruined thread in it and the bolt doesn't push it down properly anymore, so does this bolt need to be in correctly to presurise the oil through the bars. Or is it just a case of Bars being ****ty again?

I hope this makes sense, i'm not a mechanic or anything, but don't mind getting my hands dirty.

this is a very common problem on the 1.4. the oil bar is only half the story, the pick up pipe supplies oil to the bar, and that blocks up just as easily. a clear bar wont have any oil pressure if the pick up pipe is blocked. you should clean both at every service by bathing them in petrol or similar. your new cam may be damaged from oil starvation. inspect its lobes to see if it needs replacing (again), it doesnt take long to damage a dry camshaft.