HELP

[Johnnyutah]

Today I was driving my 90 MJ down the road and it started staling out, I noticed it was not getting past 1st gear (it’s an automatic) 

My first thought was that there was an oil leak as I had just changed it last night, but this wasn’t true. When I tried to restart it, it wouldn’t even turn over. No crank no start, but the lights were just fine so I assumed it was an alternator issue (I had just put in a new battery three days ago). 

I had it towed to a mechanic shop as I don’t have any diagnostic tools, and I get a call a couple hours later saying they found the engine so locked up they couldn’t even turn the crankshaft no matter how hard they tried. The mechanic suspects the oil pump went bad and said I may need a new engine. Is this accurate? 

Please tell me one of you wizards knows some arcane secret that will save me a whole bunch of time and money. Thank you!

[speeding_infraction]

First thing I would do is drain the oil and check the filter and see what's in it. I'm assuming you changed the oil filter as well? And be careful of the harmonic balancer bolt/threads if you try and get it spinning. 

[Johnnyutah]

Already did that, it came out clean

[speeding_infraction]

Trans in neutral when you try and turn the engine over?

[Spinnakerblue89]

Did you try tapping the starter? No crank can be a symptom of that. I believe a no crank condition may be a symptom of the CKPS as well. 

[Johnnyutah]

Tapped the starter and tried to start in neutral, even gave it a rolling start and all the same, nothing.

[watchamakalit]

Did the engine trouble begin the same time you noticed the oil pressure gauge feed line was broken off below the distributor?  If so the oil pressure line could well be the culprit to the demise of your engine.