Knock when first started
 

90 Ford 7.3 IDI

Sometimes when i start the truck it will knock like hell for about 3 secs and then build up oil pressure and be fine......other times it starts and dont knock.......is there an oil pump issue or something i can do to fix this problem.....doesnt matter how long it sits and its starting to do it more and more........

is it a knock or a woof? sometimes the hydro lifters will bleed down, causing a woofing back out the intake or exhaust.

Right, and you would also notice the engine will shake, like it lost a cylinder.

its def a knock........it shakes and raddles until it builds up oil pressure and then it levels out.......but dont do it all the time.......so far today it hasnt but im sure it will.....

possibly pull valve covers before first started and see if anythign is loose in the top end.

ok ill look