Oil pressure

what causes low oil pressure?

i recently had my oil changed and my oil pressure was fine but we did use the wrong oil when we changed it …it required 5w30 and we used 10w30 it ran fine but then we took it somewhere and got my oil and fuel pump changed …we changed it to the correct oil 5w30 and my pressure is lower then normal will this continue to rise now that it has the correct oil…we always used the right oil except for 1 time and my car stalled and died a few times so we had to get this checked and chaged

What was wrong with the FUEL PUMP? Or did you change your OIL PUMP? Please indicate exactly what was done, since it is difficult from your post to determine what could be wrong. Does your car actually have an oil pressure gage?

P.S. The fuel pump has nothing to do with the oil circulation system in your engine.

Using 10W30 oil won’t harm your engine one way or the other.

You don’t say what vehicle you’re driving. We need a full ID of it please. Mileage too.

Low oil pressure can come from a very low an oil level, a weak oil pump, very dirty oil or worn piston rings. (Possibly other things I haven’t mentioned as well, I’m not a tech)

I suspect the engine stalling was from a faulty fuel pump. You did say you had it changed.

Good point Doc. I flew right past that. Huge difference in answers if it was both an oil AND fuel pump or just engine oil and fuel pump.

98 chevy blazer 4 wheel drive 4.3 engine 89000 miles …my truck was fine we did a normal oil changed with the wrong oil then i started having starting problems it would turn over and not start…i took it to a mech. n he replaced the intake manifold gasket , fuel pump . n filter n changed my oil back to the right oil 5w30 but now my oil pressure is low and never was b4 i want to know if this will fix it self or if there is still a problem??

Your oil pressure would read a little bit higher when you had the 10W-30 oil in the car than with 5W-30 especially when the car was cold and warming up.

Get the car on a road with a constant 50 mph or higher speed limit and see what the reading is at those speeds when the engine is warmed up. If you watch the oil pressure guage closely you will see the needle drop off a lot when you are sitting still at stop lights, a little higher in around town driving, and higher still at highway speeds.

If you are sure the reading is not as high as it used to be that can be the oil pump failing or the screen in the oil sump (where the oil stills in the oil pan) is gunked up. A mechanic can check the oil pressure with a much more accurate guage than the one on your dashboard. If the pressure is indeed low the 1st step is drop the oil pan and check for gunk on the screen, clean it and see if the pressure returns to normal. If not, then perhaps a new oil pump is needed.

Hopefully you are justing noting a difference and it is not serious, but check it out to be sure.

That intake change bothers me,that is definitly not a minor job,what justification was given? Any chance material from the intake ended up in the oil? I can’t see changing a intake for hard starting.

Worn piston rings won’t have any effect on oil pressure.

I’m guessing you meant worn crankshaft bearings.