So I brought this vivaro and they said the crankshaft bearing has gone, so I replaced the crankshaft sensor, but the engine won't turn over, so I've tried bump starting and almost ripped off the front end, so put a spanner on bottom pulley and turns both ways till a certain point and won't move.
Won't start with key won't even intertane it, I've got it a couple time to turn over by key but sounds like battery's dead recharged battery and still nothing even though everything's a lot brighter (lights and stuff)
Any ideas ?
Running Rough, Starting & Power Loss
Sounds a lot like the initial diagnosis of a shot crank bearing is spot on,
And the crank is rotating until it hits the really bad spot and locks up.
And as all the crank bearings are oil lubricated the chances are all of them are at the very least suspect.
As to why you fitted a new CAS.............
I'd say that you only option is a S/H engine.
Repairing your one wouldn't be cheaper.