1998 Porsche 911 oil pressure

Your engine will always read 5 bar when engine is cold,usually above idle.As it warms up it will decrease due to lower viscosity(thinner oil)If it reads 5 bar w/key on only then you may have a faulty sending unit. The reason it smokes at times on startup is because its either overfilled with oil or you oil separator is starting to leak vacuum which will suck oil into the intake and try to burn it. These engines by nature will smoke at times on startup depending on how long they sit due to the design of the crankcase.The oil level slowly rises above the cylinder walls then oil seeps past the rings causing a small amount of oil to burn off on startup.Hope this helps.

i have noticed that when i am driving it now there is blue smoke coming out the back and as i said on start up there is lots of smoke coming out

it has only started to happen in the last couple of days before that it was fine no smoke on start up and no smoke when driving

thanks mick

If this is a watercooled engine then it sounds like you have a bad oil separator. water cooled engines didn't come out untill 1999.