Since I have had this car the oil pressure has always been on 60 when giving it gas and at idol, it may go as low as 50. yesterday it started going to 30 when giving it gas and at idol it goes down to around 15 or so. I have not done anything to cause this, that I know of. I checked the oil level and it is fine. I have Mobil One Etended Performance oil in it, and I was thinking of changing the oil filter to see if that helps. So fromw hat I know about these engines is to do the following (chepest to most expensive):

1. Change oil filter
2. replace sending unit
3. Oil pump is going bad

Any ideas to what this could cause this? I do not hear my lifters tapping or anything. Is there any way to tell that the oil pressure is correct in the engine, other than changing out the sending unit?

1991 TA L98

 

You can remove sender and put a oil pressure gauge in the outlet and check it that way. Best way to be sure your getting a accurate reading. You can get a manual guage with a flexible hose from auto parts or Sears. Badman

 

15 is nothing unusual for a broken in, mild to low performance engine. It could be that you had a blockage in the oil pressure gauge passage that just cleared up. 30 psi at cruise speed is about right for a high mileage engine, as long as its still running cool and not making any irregular noise, you should be fine. You can check the pressure manually like badman said, its the first step, but I wouldn't be surprised if nothing was wrong. Hope this helps,