Ok replced oil cooler went to start it took about 2min of turning over then the oil pressure gauge went to normal truck started now evrey time i go to start the tuck it takes about 10 seconds to before it will start even after cycling motor 3 times and waiting for wait to start light to come on and glow pugs and glow plug rela are only a few months old

 

if this is a direct injection engine, sounds like high pressure oil pump is not making enough pressure, or the ipr is stuck. how much oil did you put back in it and what kind