After my '97 SE (100000) have gone through major repair process I've noticed that oil pressure was dropping to 20-25 when engine was really hot after 20 minutes of driving and when stopping on a traffic light. When driving -the max reading was about 35-40 psi.
I got back to repair shop and mechanic wasn't certain of normal operation pressure for Bonneville, but tried new oil pressure sensor thinking it could be the problem. With a new senson gauge was showing same low numbers when car was hot ( when on cold readings were 35-50psi on idle and 60-70psi when driving same as I had before repair).
So the question would be : what is the normal operational pressure for NA Bonnie? and what could be wrong if it'* too low?

I'm not quite sure what is the , but in my case the filter was replaced with filter from company which starts with EVER* . Just FYI both intake manifolds,lower intake gasket,fuel injector O-ring, termostat, EGR valve, water pump,coolant pipe and coolant were replaced. EGR valve was replaced because of C/E code P0401 which is back after 100 mi anyway ( mechanic is saying that now it'* a bad PCM). Can this be a problem?[/quote]

Does Advance/Discount auto parts store have a web site?
Although mechanic is suggesting that car is drivable with that P0401 code, do I need to ask him for any specific readings from a scan tool and is there a site on the net with all specifications for Bonnevilles such as oil pressure and other?

Thanks for the reply, But I had to open another forum . If you ask me what happend - engine stalled on 70mph and I lost power steering and brakes. When I towed it to the shop they showed me pieces of shreded 6th rod and piston plus two big pieces of engine block. So I guess low pressure was a result of 6 rod going bad and collant in the cilinder because of intake manifold crack which I just fixed for 1500$.

i finally solved the problem with the P0401 CODE on my 97 bonneville 3800 vin K

believe it or not, it was caused by the repair shop leaving the PCV valve out when they changed the upper plenum...

it sits directly below the MAP sensor... they swapped the plenum and left the PCV valve in the old part... it caused the code to set...

i found out, that code is more about the MAP SENSOR'* ability to sense pressure change in the intake manifold when the egr valve is commanded on by the computer, than whether egr gasses are flowing or not...

since the pcv valve was missing, the MAP SENSOR was sensing no change in the intake manifold pressure, which told it the egr wasn't flowing... but it was really the fact that the PCV VALVE wasnt allowing the manifold pressure to build to a point that it could drop when the egr opened.... this in turn sent a false signal to the MAP SENSOR...

all over a missing PCV VALVE...
now a faulty one, (sticking open) could cause the same problem....

hope this helps you...

check or replace the PCV VALVE cheap insurance for less than $5 bucks..

Cam, your recent fix isn't the solution to everyone'* problem here. And please stop digging up VERY old topics. This one is also from 2003.