I have a '97 SSE. I have had a lot of work done lately. Today after pulling off the freeway I noticed my oil pressure guage is moving a lot. It looks like it is moving from about 23 to over 40 when the engine is reved up like normal driving speed in town. Is this what should be happening or should the oil pressure be staying around 40 all the time. I have about 99k miles on this engine and have just replaced, the belt tensioner pulley, the radiator, water pump, the plenum, the transmission sensors, torque converter, power steering reservoir, serpentine belt, fuel guage, rear wheel cylinders, hey a bunch of stuff. Now I notice the oil pressure going up and down.

WTH!!!

Turbo5

The guage built in the dash isn't 100% accurate. For the best readings, hook up an external guage. Or, it could simply be that your pressure sending unit is faulty.

On a side note, the dash reads 65 PSI pretty constantly in my 99. It has 136,000 miles.

after the car is warmed up you will see a little movement in the OP gague

Having a 97 with 144K on it I may be able to shed more light. 40 at idle warm and 60-70 about 2K rpm on highway.

Where are you located?

I am located in Alabama. I was just coming off I-59 when I noticed this. I may be just paranoid after spending a lot of money on the car, but this oil pressure guage got my attention. It was 54 degrees out today. I had just driven about 80 miles at 75 mph.

Thanks everyone for your attention to this post. We use this car a lot. I like to run around town in it and a few years ago we took a trip to California in it with no problems at all.

Turbo5

I'm right in there with BillBoost at 127K.

As others recommend, look at a mechanical gauge first and if there'* a large disparity, change the sender.

How many miles do you have on the oil? I've noticed mine with 130K miles on it dropping at idle to a lower pressure. But when I put in new 10-30 oil it doesn't drop as much. It drops most after long drives.

I want to ask if there are any wear problems on oil pump or pressure bypass controls that might cause a problem. Note I have a 98 LeSabre.

Nailed my latest thought...how many miles on this oil change?

Well it is ready for an oil change. Do you think the oil has broken down? It did run hot when the serpentine belt came off. I had just replaced the water pump when the belt tensioner failed. I usually run the Bonneville about 5k between oil changes. I believe I will run it down and have it changed tomorrow to see if that makes a difference.

Turbo5