Sounds to me like they weren't scrupulous on oil changing regimen and the motor is all 'coked up'. Maybe a Severe Duty treatment with Seafoam followed by Auto RX or similar would clean it up enough to be serviceable.

Assuming of course it's still got oil pressure and isn't knocking. It's quite obvious they don't know much about the inner workings of an engine!

'90 Troop 3.4 LS
'89 Troop RS (Has Valve Issues, needs Counseling)
HI, I'm Ed and I'm a Trooper-holic!
Keep On Troopin'......