I just purchased a 1994 bonneville sse with 170000 miles on it and everything seemed to be fine until after a long highway drive as I was getting off of the highway the oil pressure dropped... it was still above the red but pretty low...

In seperate incidents when this has occurred the car sometimes shuts off while driving down the road. I used lucas oil fuel system cleaner in the car, as well as changing the plugs and wires but this still occurs so im assuming that it is related to the oil pressure.

Is this the case and does anyone else have this problem?

If so is there anything that anyone knows, short of a rebuild to fix the problem?

I just changed the oil and put engine restore in the car but have only driven about 70 miles...not enough time to make a difference yet. Any help would be appreciated..

you mention how the car is at ldle...how is the car'* presssure at a crusing speed

I would you recommend you get a mechanical OP gague on there

I agree with Pat. A mechanical oil pressure gauge will give a better idea of the true pressure. Also, what the pressure is at cruising speeds can be helpful. Do you know what the maintenance history of the car has been? Has the oil been changed at regular intervals? What oil and weight of oil are you using now?

At cruising speed the needle is floating around the 40 mark on the gauge but as soon as the rpm drops, if the car is warmed, the needle drops to just above the red mark...
When the car is still cold however there is no problem wilth the oil pressure.

I am looking for the cheapest solution as I only plan to have the car for a few more months,

As for the oil, it is pennzoil 10w30 and I do not know the history of the car whatsoever

Do an oil change and see what happens. Mine did the same thing, when cold, the psi was high at low and high rpm. After it warmed up, the psi was low no matter the rpm. I did an oil change and it went back to normal.

when you do the oil change use a AC Delco PF47 filter too

hey my car did the same and i was not waching close. cange oil and spark pluges and chak the comperson on the cilinder and oil prisher too be cuse you should be siting on about 1000rpm and have about 60 psi or more++++++ so cheak thos out be for something gos roung

Dogman, can you PLEASE try to make your posts make some sense? I can't understand half what you're trying to tell us.

PLEASE use a spell checker of some sort.

If, and only if an oil change does not resolve the problem, try replacing the pressure release spring. They are a few dollars at the dealer I believe.