I have a cam chain that rattles on start up , which is the oil pressure not being up into the tensioner on the chain tensioner its self,the oil drains back from this part and so leaves the chain slack, so on start up you will here the chain rattle untill pressure is up , then the tensiomn is taken up on the chain and the rattle goes away ,this i belive thi is a fault in the tensioner and there is a special part to replcae the faulty part,if the rattle is longer than say 20 seconds on start up you have a problem, if its only a few seconds and then all is well, you have a problem but need not rush to sort it out , but do sort it out somewhere along the line , i am hoping i will only need the tensioner on my 60.000 mile motor , but in the worst case it could be the entire set up chain sprockets tesioner kit the lot on a high millage motor.
