1993 Chevy S-10 Pickup, 4.3 motor, 174,000 miles, stock oil pressure gauge reads 20 lbs. with fresh oil change

Question

Running 5w-30 now, only had truck for 3,000 miles and oil pressure gauge has always fluctuated.....either sticks at 40 or gets pinned to top with acceleration. Now changed to thinner oil, pressure gauge reads 20 lbs, just barely, and rises to 40 lbs. when accelorating. Is the gauge messed up? Perhaps the oil pump is weak or on its way out? How tough is it to change the oil pump? Truck runs great otherwise. Thanks in advance.

Answer 1

To change the oil pump you must get into the oil pan. but sounds to me like wore out rings. try changing the oil pressure sending unit first or installing a separate oil gage. the after market kind and see where the oil pressure is at before changing rings or oil pump.

Answer 2

I like how people always suggest to "dump" a vehicle instead of giving you an answer. If you wanted to dump it you wouldn't be here asking how to fix it. And you probably bought it because you like it and it was what you could afford.

At any rate let me try to help you. First off it sounds like either your gage or the oil pressure sending unit is malfunctioning. You could replace the oil pressure sending unit and see if that corrects the problem. However this is not an easy task on the 4.3 liter. It is in the very back of the engine and very difficult to get something on it to change it. They do make an oil pressure sending unit socket to make it easier to change one.

Now let's say the oil pressure reading is 20 psi at idle and rises to 40 on acceleration. I wouldn't call this a terrible reading if it was accurate. I looked at the specification on AllData and their minimum specification is 24 PSI at 4000 rpm. And 18 PSI at 2000 rpm.

I would have to agree with them. As long as you have good flow then 20 PSI at idle and 40 on acceleration is not all that bad.

Enjoy your truck. I like S10 pickups

Answer 3

Do yourself a favour and dump this lemon - I had one of those and I had to replace just about everything on it it was in the shop on a weekly basis for a time.In 15 years only 174 000 miles ??

I wonder !