Decreased oil pressure

[teddysgirl]

Help!
My Buick LeSabre (1988) oil light keeps coming on. It flashes on and off at times, but mainly stays on once it does comes on. This is at normal idle or non-highway driving when the speed is low. I had a oil pressure test done and they concluded that there was only 8 pounds of pressure when there should be 35! The garage told me that it could be a number of things including the oil pump, sensors, the inserts, etc. I just found out that instead of putting the normal 10W30 SAE oil during my oil changes, the garage was putting in 5W30 SAE. Is it possible that this little viscosity stripped the pump and my only problems is the pump? Or could it be something else? I don't exactly feel like shoving a ton of cash into finding out what it is. Please, if anyone knows, save my frustration!!!

[yogi_123rd]

I believe your oil pump is showing it's age.

Infrequent oil changes, running the engine when low on oil, or running dirty oil wears the pump over the life of the engine. Modern mullti-viscosity oils are thin compared to oils used before they were invented 40 years ago.

The oil light is more of an indicator when you have NO oil pressure (very bad) than LOW oil pressure (oil is still flowing). In your case, you should try using a thick straight weight oil, 30w or 40w and see if there's any difference in how the oil light behaves. The only problems you may have using these thicker oils would be in the winter months when initially starting the car.