My '96 GC with 260,000 miles has developed an oil pressure problem!

When coming to a stop after the engine is warm the oil pressure will drop to zero.

If I throw it into neutral or pick the RPM's up to 750 it comes right back to reading 25 on the gauge.

It starts & runs fine, burns no oil, & I don't hear any knocks or bearing noise.

If I were silly enough to think about changing the oil pump .......what kind of job would I be looking at?

Would using 5w-50w oil help the problem?

The vehicle is used as a backup (I don't think I put 500 miles on it in the last year), but it still looks & drives well.

I like to have it (V8) around to pull a car trailer once in awhileI'd like to keep it if it is cost effective.

Thanks in advance

UPDATE
I'm happy to report that the oil pressure problem has been solved with two simple changes, #1 - I stopped using Fram oil filters & started using Wix filters! #2 - I switched from 5w/30 oil to 10w/40 oil! Since making these changes I have used the Jeep to tow a Rally car on a heavy steel decked trailer hundreds of miles in summer heat without a single problem!
I hope this may be helpful to someone!

_________________
Rich, N2ZKX
Black 2006 KJ
“Laissez les Bon Temps Roulez"