oil pressure up and down
Have 88 GMC 4x4 owned since new, now has 150,000 miles. Oil pressure sometimes 45lbs cold-30lbs hot. Other times 25lbs cold- 5-0lbs hot ! Gauge alert comes on at idle.
Whats going on? This has been happening for 2 months. Changed oil, filter, still no change. Could it be the sending unit? Not sure where it is, unpluged the one by the distributor...no change, aparantly that's not it!?
Anyone have a problem like this before? Would appreciate all responses.
Thank you, Roger B.