Pontiac Owners Club UK

What should the oil pressure be for a 3.8 v6 1998 firebird?

Currently when cold mine is half way (60psi) on idle and goes up a bit when you rev it. But as it warms up it drops to just above the 1/4 mark (which I guess is around 30-40psi) when going along. Does that sound right or is that too low? I just had the oil and filter changed (10w 40). I'm pretty sure it was on the 1/4 mark the whole time even when cold before, so at least there's a bit of an improvement!

If it's too low what could it be? Oil pump, or something more serious? I've just confirmed I have a leaking head gasket as well so that will mean engine out, but if there's loads more to also do it may not be worth it

sounds reasonable to me

main reasons for low oil pressure are pump fault/wear or big end/main bearing wear allowing oil pressure to escape round crank journals

These engines commonly suffer with inlet manifold gaskets deteriorating leading to water contaminating the oil and the oil pressure dropping that is why it comes back when you change oil and filter for a while....I.E. its not the head gaskets. If run like this for too long the engine will hydraulic and be wrecked.