Oil pressure

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??

If you used a very heavy single grade oil, such as straight 40 in cold weather, you could have problems with not turning over. What was the “wrong oil”?

Changing back to 5W30 and having low oil pressure (do you have an oil pressure gage on the truck?) indicates some other problem. Thick oil will not wreck your oil pump by itself.

Please tell us more as to exactly what you did and why.

10W30 Was the wrong oil,do you thing my gauge is bad??

What is the oil pressure at different rpms and what should it be according to the specifications for the engine?
Since you are measuring with the dash gauge, you need to cross check that indication with a direct reading test gauge.

See my response to your 1st “oil pressure” post.

There are 3 or 4 different issues going on here, but oil is not one of them. You can’t blame ANY of your problems on the oil, 10-30 or 5-30, your engine will be happy. Perhaps the oil pressure sender, located on the back edge of the block right next to the recently disturbed intake manifold got disturbed too…Anyway, that’s the first thing to check, the sender.

10W30 in a 1998 vehicle is OK, especially a GM vehicle with wide tolerances. Your engine does not really care whether it has 10W30 or 5W30. Your gage could indeed be bad. You need to have the pressure measured by a mechanic and compared to what it should be. The mechanic will also have to test the sending unit and the gage.

I had a similar problem in the past; the oil light was red, but it turned out to be a short in the sending unit. To repeat, 10W30 will not damage your oil pump.