not a vanagon owner here but your turbo could have worn through on the shaft. Could be looking at a rebuild
?
with torque to yield stretch bolts, the torque sequence could have come with the head gasket?
My bentley says
Torque the bolts to 40 Nm (30 ft. lb.), in the sequence shown in the pic i posted there above. Repeat the sequence, torquing the bolts to 60 Nm (44 ft. lb.). Repeat the sequence a third time, tightening each bolt an additional 1/2 turn. Alternatively, this last step may be done as two 1/4 turns.
Run the engine until it reaches normal operating temperature. Retorque the cylinder head bolts in sequence 1/4 turn without loosening. For engine codes ME and MF only, after appx. 1000 miles, retorque the cylinder head bolts an additional 1/4 turn, without loosening and without "interruption" - so very smoothly and fluidly.