1990 Suburban 454 Oil Pressure jumping

[StMetallica]

What’s up guys. New here on but don’t know where to start so here we go.

I have a 1990 Suburban 454 2WD that I recently purchased it about 4 months ago.. Has 220k on it. When I purchased the truck the oil pressure would read at 28 - 30psi and I daily drive it. Never had an issue. About a week ago i was driving home and when I left a red light the truck hesitated like it was being restricted have it gas and it cleared up.. I noticed that the oil pressure is now reading at almost 60psi now and the truck seems the have more power as well.. enough to notice.. and my fuel gauge seems to not be moving either.. last night when I got home it felt like the truck was idling very low and almost killed itself but right before it died it idled back up.. so Idk what’s going on.

I changed the oil pressure switch recently cause the fuel pump was staying on after the truck was turned off. Nothing changed .. I also did an oil change on it about a month ago because it was super low on oil. But the gauge never changed after that until like a week ago.

I guess my main question is where do I start the process of elimination to find out why it’s hesitating plus the oil pressure issue.. thank you.

 

[midwest]

I'm no mechanic but have been around square bodies long enough to know I would not assume your pressure was 28 before, or that it is close to 60 now. First thing I would do is to get a reliable alternate method to confirm your oil pressure, other that the stock gauge. Your factory gauge could very well be exactly right, or it could be way off...

 

[Camar068]

I would do an engine oil flush and check/replace your sender. I say the engine flush cuz you say it suddenly has more power and oil pressure.

and by oil flush, I mean a drive way flush....not one that you add stuff to it and drive ~200 miles then change the oil.

 

[Gardendelite]

Good morning StMetallica, I would be curious to hear an update.

 

[Gardendelite]

PS, I have a 75 K10 with a mild 350. I ran with low oil pressure for almost 10 years. My son borrowed the truck and it overheated. Not sure what cause what but it appears to have blown one of the main bearings. I will likely never know what happened but it ran like a champ with low oil pressure for years. 10 at idle and never more than 30 at 3000 rpms.