Topic: Olds 403 oil pressure

[10YR TA]

My 79' with the olds 403 has 120,000 miles on her. Runs great with no problems. While driving my oil pressure gauge sits between 20 - 40. At idle down near 20. Oil is full and newly changed. Does this sound normal? Anything would be helpful.Thanks.
New to this site and I have already learned alot.

[Trans am Oz]

G'day 10YR TA

When we first got or 78 Olds powered TA we had oil pressure problems from the get go....when cruising along the road the psi would be around 30 then drop down into the red when at idle,so we got the bottom end rebuilt and now the oil pressure sits on or around 30 at idle and when cruising around the 60 mark.
Make sure you have the correct type of oil for that car... would be some thing i would check first

hope that helps

[10YR TA]

Do you reccomend a certain oil? What weight? Thanks

[ta78w72]

How did you validate the gauge accuracy? 

[10YR TA]

I haven't done anything yet.

[Jolley_Man666]

I would suggest 5w30. If that doesn't help it could be your oil pressure sending unit

[dewcrazzy]

my 403 read in the red while idling and then I went to the zone and hooked up an after market gauge and it read 45 while driving and around 25 at idle. I ran a post also and a few guys said that was about normal

[Maryland Bandit]

Bone stock 70,000 mile 403 here. When warmed up, idle oil pressures varies between 20-30 llbs. On the highway cruising, 45 lbs. Use 10w-40 oil and a can of STP oil additive, no problems. 

[Trans am Oz]

we had a dead give away with ours..motor started knocking at idle
A good spin on it was that the timing chain needed replacing and the harmonic balancer was about to fall off

[RENOVATIONS]

I would suggest 5w30.

That's some pretty thin oil

[Amtrak]

use 10w40 or 30wt oil